NASA Technical Memorandum 104636

f

Atomic Oxygen and Space Environment

Effects on Aerospace Materials Flown

with EOIM-III Experiment

John J. Scialdone, Carroll H. Clatterbuck, Mary Ayres-Treusdell,

Gloria Park, and Diane Kolos

November 1996

Errata

Table 3, pages 9 and 10, under the Thermo-Optical Properties columns' identifications:

• The two Absorption titles should be changed to Absorptance.

• The Absorptance column on the left reflects the absorptance values before

flight. The absorptance column on the right reflects the values after flight.

References, page 33: The name of the co-author in reference 1 indicated as Visentive,

should be Visentine.

NASA Technical Memorandum 104636

Atomic Oxygen and Space Environment

Effects on Aerospace Materials Flown

with EOIM-III Experiment

John J. Scialdone, Carroll H. Clatterbuck, Mary Ayres-Treusdell,

Gloria Park, and Diane Kolos

Nationa_ Aeronautics and

Space Administration

Goddard Space Flight Center

Greenbelt, Maryland 20771

1996
This publication is available from the NASA Center for AeroSpace Information,

800 Elkridge Landing Road, Linthicum Heights, MD 21090-2934, (301) 621-0390.
Table of Contents

Abstract ........................................................................................................................ 3

1.0 Introduction ....................................................................................................... 3

2.0 Experimental ............................................................................ . ......................... 6

Table 1. Materials List ......................................................................................... 7

Table 2. Cumulative Solar Ultraviolet Spectral Incidence ..................................... 6

Table 3. Summary of Polymers Reaction Efficiencies ........................................... 9

2.1 Data and Measurements Taken ................................................................. 12

3.0 Sample Description and Flight Results .............................................................. 13

3.1 CV-1144-0 Silicone on Delrin .................................................................. 13

3.2 CV-2500 Silicone on Delrin ..................................................................... 14

3.3 Delrin II 900 ............................................................................................ 14

3.4 Epoxy Fiberglass, G-11 with a Flame Retardant ....................................... 15

3.5 Epoxy Fiberglass, G-11 with no Flame Retardant ..................................... 16

3.6 CV-1144-0 Silicone on Silver Coated Teflon ............................................. 1 7

3.7 CV-2500 Silicone on Silver Coated Teflon ................................................ 1 7

3.8 Teflon with Silver Coated Backing ........................................................... 18

3.9 Silver coated Teflon (with center hole cut-out) ........................................ 19

3.10 CV-1144-0 Clear Silicone Coating on Kapton H Film ............................... 20

3.11 CV-1142 Silicone Coating on Aluminum ................................................. 21

3.12 CV-1500 Black Silicone on Aluminum ...................................................... 22

3.13 CV-2566 Red Silicone on Aluminum ........................................................ 22

3.14 X389-7 Beta Cloth on Aluminum Backing (Beta Cloth Exposed) .............. 23

3.15 CV-1144-0 Silicone on Beta Cloth ........................................................... 24

3.16 Chemglaze Z306 Paint ............................................................................ 24

3.17 Ultem-1000 ............................................................................................ 25

3.18 Peek 450G .............................................................................................. 26

3.19 CV-2500 Silicone on Kapton-H Film ........................................................ 26

3.20 Polyethersulfone 4800 G (PES) ................................................................ 27

3.21 Polymethylpentene (TPX) Film ................................................................ 27

3.22 3M Pressure Sensitive Tape No. 5 ............................................................ 28

3.23 Uralane 5750 LV- A/B ............................................................................. 29

3.24 Uralane 5753 LV- A/B ............................................................................. 29

3.25 Epon 828/Versamid 140/Ti02 ....................................................................................................................................... 30

3.26 Aluminized Beta Cloth X389-7 (Aluminized Exposed) .............................. 31

4.0 Analysis of Results ............................................................................................ 32

5.0 Conclusions ..................................................................................................... 33

6.0 Acknowledgments ........................................................................................... 33

7.0 References ....................................................................................................... 33

8.0 Figures ............................................................................................................. 35

Atomic Oxygen and Space Environment Effects on Aerospace Materials

Flown with EOIM-III Experiment

Abstract

Polymer materials samples mounted on a passive carrier tray were flown aboard the STS-46

Atlantis shuttle as complement to the EOIM-III (Evaluation of Oxygen Interaction with Materials)

experiment to evaluate the effects of atomic oxygen on the materials and to measure the gaseous shuttle bay environment.

The morphological changes of the samples produced by the atomic oxygen fluence of 2.07E-20

atoms/cm 2are being reported. The changes have been verified using Electron Spectroscopy for

Chemical Analysis (ESCA), gravimetric measurement, microscopic observations and thermo-optical measurements. The samples, including Kapton, Delrin, epoxies, Beta Cloth, Chemglaze

Z306, silver Teflon, silicone coatings, 3M tape and Uralane and Ultem, PEEK, Victrex (PES),

Polyethersulfone and Polymethylpentene thermoplastic, have been characterized by their oxygen reaction efficiency on the basis of their erosion losses and the oxygen fluence. (See Table 1

for source name.) Those efficiencies have been compared to results from other experiments,

when available. The efficiencies of the samples are all in the range of E-24 g/atom. The results

indicate that the reaction efficiencies of the reported materials can be grouped in about three

ranges of values. The least affected materials which have efficiencies varying from 1 to 10 E-25

g/atom, include silicones, epoxies, Uralane and Teflon. A second group with efficiency from 10

to 45 E-25 g/atom includes additional silicone coatings, the Chemglaze Z306 paint and Kapton.

The third range from 50 to 75 E-25 includes organic compound such as Pentene, Peek, Ultem,

Sulfone and a 3M tape. A Delrin sample had the highest reaction efficiency of 1 79 E-25 g/atom.

Two samples, the aluminum Beta cloth X389-7 and the epoxy fiberglass G-11 nonflame retardant, showed a slight mass increase.

1.0 Introduction

The Atlantis Shuttle STS Mission 46, of July/

August 1992, carried in orbit a large number

of experiments collectively grouped under the

designation of Evaluation of Oxygen Interaction with Materials (EOIM-III)--third phase. The

experiments had been designed: (1) to provide atomic oxygen reactivity measurements;

(2) to understand its reaction mechanism and

dynamics; and (3) to characterize the induced

environment in the shuttle bay. The instruments to carry out these functions are depicted

in Figure la.

The experiment instrumentation included a

mass spectrometer for measurement of the

gaseous atomic fluxes and other instrumentation to verify the environment, the direction

and energies of the various fluxes. Among these

test experiments were 15 passive tray carriers,

identified in Figure la by the letter N, carrying

samples provided by NASA centers, Aerospace

Corporation, University of Alabama, European

Space Agency, Canada Space Agency and Japan Space Agency. These trays, shown in Figure 1 b, included nominal openings of 1/2" and

1" diameter which accommodated materials

samples mounted on aluminum backing disks.
MPESS

PALLET 2

BAFFLE

B

ATOMIC INTERACTION EXPERIMENTS:

A - HEATED PLATE (JSC), 3EA

B - ATOM SCATTERING EXPERIMENT (UAH), 1EA

C - ENVIRONMENT MONITOR PACKAGE (GSFC), 1EA

D - SOLAR UV EXPERIMENT (JSC), lEA

E - STATIC STRESS FIXTURE (MSFC), 2EA

F - UNIFORM STRESS FIXTURE (MSFC), 2EA

G - ATOMIC OXYGEN MONITOR (MSFC), 1EA

H1 - COMPOSITE STRESS FIXTURE (LaRC), 2EA

H2 - COMPOSITE STRESS FIXTURE (JSC), 2EA

FORWARD

SPECTROMETER PALLET 1

CAROUSEL 20O

A

I - SCATTEROMETER (JPL), 2EA

J - MECHANICAL STRESS FIXTURE (LeRC), 1 lEA

K - REFLECTOMETER (LeRC), 2EA

L - PINHOLE CAMERA (LeRC), lEA

M - SCATTEROMETER (AEROSPACE CORP.), lEA

N - PASSIVE SAMPLE CARRIERS, 15EA

O - VARIABLE EXPOSURE TRAY, lEA

P - FREEDOM ARRAY MATERIALS EXPOSURE

EXPERIMENT (LeRC), lEA

Q - QUADRUPLE MASS SPECTROMETER, lEA

Figure la. A line drawing of the EOIM-III payload identifying the various features.

The forward edge of the payload is at the bottom of the line drawing.

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The passive trays were not temperature controlled, however, other trays were. Among

these passive trays, the one indicated as N-5

was provided by the Materials Engineering

Branch of GSFC. It included 49 samples prepared by GSFC, 27 by GE-Astro, 4 by IITRI and

2 by Martin Marietta. The samples consisted

of thermal control paints, films, coatings and

other assembly and construction materials. This

report will cover only the samples prepared by

GSFC (Table 1), since the guest samples were

returned for analyses to their respective organizations. Of the GSFC samples, film samples

are not reported in this paper, as they were reported in another document, NASA TM104621. The analyses were carried out to evaluate the effects that the oxygen flux, in conjunction with UV radiation, ionizing radiation, thermal cycling, plasma interaction and

micrometeroid/debris, have on materials used

for or proposed for space applications. These

types of environments, especially Atomic Oxygen (ATOX) modified by orbit altitude, spacecraft inclination and by instruments' orientation, have been shown by many flight experiments to degrade materials and S/C performances. The characterization of those effects

consists of the evaluation of the exposed material thermo-optical properties, its surface erosion and/or the rates of changes of those parameters.

2.0 Experimental

The STS-46 Atlantis flew at an altitude of 228-

230km (123-124 miles) with an orbital inclination of 28 ° . The trays and other experiments

were exposed for 58 hours. The materials oriented for normal incidence were exposed to

average fluxes of 1.5 x 1015 cm 2 s1 consisting

mainly of O, N2, 02 and H. The temperature

was passively controlled and with some exceptions, it ranged between 15°C and 40°C. The

atomic oxygen fluence was 2.07 x 102o atoms/

cm 2. The fluence was reported to be in agreement with a fluence based on the Kapton erosion and its reaction efficiency (ref. 1).

Table 2 shows the solar UV spectral incidence

(as reported in ref.2) experienced during flight.

Table 2. Cumulative Solar Ultraviolet

Spectral Incidence

Wavelength, nm Cumulative incidence

J/cm z

250-200 22.4

200-150 1.1 0

150-119 0.128

121.5 0.103

119-10 0.04

The samples listed in Table 1, were vacuum

baked at 65°C for 48 hours previous to the

flight. The mass of those samples were recorded

at that time. An additional mass measurement

was carried out near the flight date. On return

from flight, the samples were reweighed. An

additional mass measurement of the samples

was carried out after exposure to a vacuum for

48 hours at 20°C. This last measurement was

performed to eliminate any contaminants

which may have been deposited on the samples

from the time of landing. The mass loss in orbit was then assumed to be the difference from

the mass measured nearest to the launch time

and the mass measured after the last vacuum

exposure at 20°C.

The results are shown in Table 3. Based on the

mass loss and the fluence, a reaction efficiency

has been calculated. It should be noted that

the samples have been protected in a container

against possible contamination.

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NOTES FOR TABLE 3

Fluence: 2.07 E20 atoms/cm 2

FLIGHT: STS-46 Atlantis

ORBIT: 228-230 km, 28 ° Inclination

Sample Area: 1.2449 cm _

Sample Area: 0.81 07 cm 2(Exposed)

(1) Control Sample Emittance: The two indicated values of the control (not flight sample)

were measured at different times as indicated

on the reflectance plots. The samples were

maintained in a clean closed container held at

ambient conditions. The flight sample emittance could not be measured because of the

measuring instrument's limitations for holding

the small flight samples.

(2) These samples indicated a mass increase following the flight exposure. The nature of the

mass increase has not been explored. It could

be attributed to increases of oxygen or contamination.

Ca) The densities' values are obtained from

manufactures' data or from literature. The actual values for the tested coatings may be different due to their preparations, their coating

layering and/or air inclusions. They are included

so that they may be used, if desired, to obtain

reaction efficiency in terms of eroded volume,

cm3/atom.

(4) The percent change of the absorptance is

affected by the thickness of the coating and

the backing materials.

As a reference, the commonly agreed oxygen

reaction rate for Kapton is 4.26 x 10 .24 g/atom

or 3 x 1 0.24cm3/atom.

11
The characterization of each sample is indicated

in the following pages, and it includes: the

sample descriptions, the measurements taken,

and the exposed sample analyses.

The samples were prepared and mounted in

accordance with the sketch below. In general,

the sample material was applied to an aluminum substrate either directly or with an adhesive, or the sample was simply supported in the

receptacle. These samples were then assembled

and held in place as shown in the aluminum

tray, Figure lb. The samples were partially

shielded and held in place with the aluminum

cover, as shown in Figure lc below.

2.1 Data and Measurements Taken

The effect of the space environment on the

samples is indicated by providing the following descriptive parameters.

The sample weight loss (g): this is the difference between the weight of the samples before and after the flight missions.

Comparisons of the spectral reflectance, the

integrated absorption and emittance of the

coatings, before and after space environment

exposure were made. These were measured

using the Perkin Elmer (P.E.) _-9 spectrophotometer.

SAMPLE ON SUBSTRATE SURFACE

CARRIER

,_ COVER PLATE

WAVY SPRING WASHER

(AS REQ'D)

ASSEMBLY

i I. 0.520 -" '_1 -L

CARRIER

FILLER (AS REQ'D)

.030

±

I

-_--

032 At STOCK ---_I=

+0.000

0.495 _

SAMPLE SUBSTRATE

NOTE: THE DIMENSION ARE IN INCHES

Figure lc. Sample Carrier Assembly

12
The Electron Spectroscopy of Chemical Analysis (ESCA/XPS) was used as part of the surface

analysis to determine elemental and chemical

composition of the samples within a depth of

100 _, (up to some 50 monolayers) employing

x-rays to emit photoelectrons.

Photographic and microscopic documentation

shows the reference and flight surface appearances and related evaluation of the changes that

may have occurred following space exposure.

3.0 Sample Descriptions and

Flight Results

The figure number indicated with the sample

title refers to the pictorial view of the flight control sample.

3.1 CV-1144-0 Silicone Coating on Delrin II

(Figure 2)

Sample Description

This sample is made of a one part, diethyl silicone copolymer dispersion overcoat specifically

designed for atomic oxygen surface protection.

The silicone has low outgassing, and excellent

adhesive properties. It contains a thinner and

is ready for use as-received for brush, dipping,

and spraying application.

Sample Configuration

The silicone sample thickness was 0.30988 cm

and its mass was 0.04610 grams. The Delrin

was self supporting and was not attached to a

substrate. The silicone was applied directly to

the Delrin surface by brush and properly cured.

Visual Inspection

The shielded area of this exposed sample is

white and shiny and the outer edge is recessed.

The exposed area is yellowed, raised, and pitted. There is an oval spot near the center that

is not as shiny as the rest of the area.

High Magnification Inspection

The sample shows a faint yellowing when compared to the control. This point is too subtle to

document. Cracks, especially near the edge of

the material, are evident. Those cracks get finer

towards the center of the sample. Possible particle impact areas exist. The control sample,

on the other hand, is transparent and no yellowing or cracking is visible.

ESCA Analysis

The sample is a Delrin II 900 NC10 with a CV1144-0 silicone over coating. The control specimen contains carbon, oxygen, and silicon. The

chemical states of carbon and silicon correspond to the silicone. The flight specimen does

not indicate any change in chemical composition. The same elemental composition, as well

as the identical chemical states, were detected

on the flight specimen as the control specimen.

Radiative Properties

The loss of reflectance is shown in Figure 3. The

absorptivity changed from 0.401 to 0.492. The

emissivity as measured on the control sample

was 0.926 - 0.91 2. The emissivity for the preand post- flight sample are not reported since

the sample could not be fitted in the available

spectrophotometer.

Physical Analysis

The mass gained by the sample was 7.3 xl 0 .4g.

The percent of the mass change when attributed to the coating was estimated to be 0.1280.

Oxygen Erosion

The reaction rate based on the above mass

gained, the fluence of 2.07 x 10 _2° atom/cm 2

and the exposed area of 0.81 073 cm 2 is 4.355

E-24 g/atom. This is a negative reaction rate,

i.e., a gain of mass as a function of atoms impingement.

13
3.2 CV-25OO Silicone Coat On Delrin

(Figure 4)

Sample Description

This sample is a two component, clear, CV-2500

silicone overcoat for surface protection from

extreme environmental conditions. It has excellent low outgassing, and is commonly used

for protection of electronic assemblies and components. It is also usable as an adhesive in low

strength applications.

Sample Configuration

The thickness of the silicone was 0.37084 cm

and its mass was 0.29302 grams. The silicone

was applied directly to the surface of the Delrin

by brush and properly cured.

trol sample was 0.929 with an eventual change

with time to 0.920. The reflectance in Figure 5

shows changes in the range of 400 to 1000

nm and from 1700 to 2400 nm.

Physical Analysis

The mass loss of the sample was 3.82 x 10 .4 g

which attributed to the coating, corresponds

to a coating percentage loss of 0.224.

Oxygen Erosion

The oxygen reaction rate based on the above

mass loss, the oxygen fluence and the exposed

sample area of 0.81073 cm 2 is 2.276 x 1024g/

atom.

3.3 Delrin II 900 (Figure 6)

Visual Inspection

The CV-2500 silicone coating on Delrin on the

shielded area of the flight sample was compressed and smooth. The exposed area, on the

other hand, was discolored (yellow) and shiny.

Low magnification of the sample showed evidence of cracking.

High Magnification Inspection

The high magnification showed more visible

cracking.

ESCA Analysis

This sample is a CV-2500 silicone coating on a

Delrin II NC900 substrate. There is no chemical change in the CV-2500 silicone coating as a

result of the space exposure. Both samples,

the flight and the control, indicate similar composition on the surface and contain C, O and

Si. The binding energies of the Si and O peaks

match the binding energy values of silicone.

The control sample contained, in addition to

silicone, some SiO 2.

Radiative Properties

The absorptance of the coating changed from

0.394 to 0.466 and the emittance of the conSample Description

Delrin II is an acetyl homopolymer crystalline

injection molding resin having excellent stiffness, tensile strength, and creep resistance under a wide range of temperature and humidity

conditions.

Sample Configuration

The thickness of the sample was 0.33553 cm

and its mass was 0.55317 grams. The Detrin

sample was attached directly to the surface of

a an aluminum carrier disk with a pressure sensitive transfer adhesive.

Visual Inspection

The shielded area of the Delrin 900 NC 10 was

depressed and smooth. The exposed area was

raised and soft.

High Magnification Inspection

The Delrin exposed area was smoother than the

protected area.

ESCA Analysis

The control specimen of the structural polymer

called Delrin II 900 NC1 0 has carbon, oxygen,

and a small amount of fluorine. The 67% of

14
carbon is in C--O bond, and 33% isin C-(H,C)

bonds. Theflight specimen,on the other hand,

hascarbon, oxygen, siliconand atrace amount

of chlorine. The silicon, fluorine and chlorine

appearto be surfacecontaminants. Thechemical state of carbon on the flight specimenconsistsof 59% of C=O, 19% C-O, 22% C-(H,C)

bonds.

Radiative Properties

The reflectance of this sample is shown in Figure 7. Loss of reflectance occurred in the 400-

700 nm wavelengths, with a few percentage

losses in the range beyond 1000 nm. The absorptance changed from .384 to .403. The

emittance of the control was .910 and with time

became .895.

mosetting epoxy resin binder. The G-11 is similar in all properties to the grade G-11 non-flame

resistant, but is formulated to have at least a V1 classification when tested to UL 94.

Sample Configuration

The thickness of the G-11 epoxy fiberglass was

0.15011 cm, and its mass was 0.33968 grams.

The sample was self supporting and not attached to a substrate.

Visual Inspection

The shielded area of the sample is tan/yellow,

uniformly textured (not smooth) and slightly

reflective. The exposed area was darker, less

reflective, white with a regular pattern which is

clearly visible within the sample.

Physical Analysis

The mass loss was 3.0 x 10 .3 g of the total.

Oxygen Erosion

The oxygen reaction rate based on the weight

loss, the exposed area and the fluence of 2.07

x 102o was 1.7905 x 10 .23g/atom.

3.4 Epoxy Fiberqlass, G-11, with a Flame

Retardant (Figure 8)

Sample Description

The G-11 epoxy fiberglass was a reinforced laminate product of multi-layers of a continuous filament of glass fabric, impregnated with a therHigh Magnification Inspection

The exposed region is darker and appears

smoother than the shielded part.

ESCA Analysis

The sample is a composite used for structural

purposes. The flight specimen showed a few

damaged areas where the surfaces had been

scratched. The scratched area, and the unaffected area on the flight specimen, as well as

the control specimen, were analyzed. The elemental compositions and the chemical state

of carbon of these three areas are listed in the

table below. The atomic percents listed in the

table are approximate numbers.

C

O

N

Si

Br

Sb

Elemental Composition and the Chemical States of Carbon

in the G-11 Epoxy Fiberglass

Elements Control Scratched Area Unaffected Area

(Flight) (Flight)

82 atom %

12

5

0.3

61 atom %

31

2

5

67 atom %

26

2

3

1.6

1

Bonding States Control Scratched Area Unaffected Area

O-C=O 35%

C=O 49% 31% 23%

C-O 19% 39%

C-(H,C) 51% 15% 38%

lb
The presenceof antimony on the scratchedarea

suggeststhat the surfacewas damaged with a

substance that contained antimony.

Radiative Properties

Figure 9 shows that there was some small improvement in the reflectance of the sample. The

absorptance changed from 0.643 to 0.657. The

emittance of the control was .906 and later was

0.903.

Physical Analysis

The epoxy fiberglass mass loss was 1.0 xl 04g.

Oxygen Erosion

The reaction rate computed for this sample was

5.958E-25 g/atom.

3.5 Epoxy Fiberglass, G-11, with No Flame

Retardant (Figure 10)

Sample Description

The G-11 epoxy fiberglass was a reinforced laminated product of multi-layers of a continuous

filament glass cloth which has been impregnated with a thermosetting epoxy resin binder.

This product was laminated under high pressure and temperature to form a dense solid

product capable of having good mechanical

and electrical properties. It has no flame retardant properties.

Sample Configuration

The thickness of the G-11 epoxy fiberglass was

0.18288 cm and the mass of the sample was

0.33570g. The sample was self supporting and

was not attached to a substrate.

Visual Inspection

The shielded area of the epoxy fiberglass is dull

and pale mustard in color. The exposed area

was "velvety" with a mustard color.

High Magnification Inspection

The sample exposed surface is smoother and

darker than the shielded area.

ESCA Analysis

This sample is a G11 epoxy fiberglass structural

polymer. The control specimen has carbon,

oxygen, nitrogen, silicon, fluorine, and trace

amounts of chlorine and sulfur. The carbon on

the control specimen is in C-(H,C), C-O, C-F

bonds. The flight specimen has all the elements

in the control specimen except chlorine. There

was more oxygen and less carbon on the flight

specimen than the control specimen. Furthermore, no C-F bonds were detected on the flight

specimen. Only the C-(H-C) and C-O bonds

were detected.

The increase in oxygen concentration and the

absence of C-F bonds indicate the chemical

change that occurred on the exposed surface.

Radiative Properties

Figure 11 of the sample reflectance shows that

with the exception of a loss of reflectance in

the 400-650 nm region, the sample developed

a slightly improved reflectance. The absorptance changed from 0.692 to 0.720 and the

control emittance was 0.91 0 and later 0.908.

Physical Analysis

This sample showed a mass increase of 6.87 x

104g.

Oxygen Erosion

Based on the mass increase of the sample, a

negative reaction rate of 4.023 x 10 .24g/atom

can be calculated. The increase does not appear to be resulting from contamination.

16
3.6 CV-1144-0 Silicone on Silver Coated

Teflon (Figure 12)

Sample Description

This sample was a one part diethyl silicone copolymer dispersion applied over a Teflon (FEP)

surface. This silicone was specially designed

and processed for atomic oxygen resistance in

space applications and has an extremely low

outgassing property. The CV-1144-0 was prepared by the manufacturer as a RTV dispersion

in a thinner for application by brush, dipping,

or spray.

Sample Configuration

The thickness of the sample was 0.1 7754 cm

and its mass, 0.1 0883 grams. The silver Teflon

(FEP) was attached to an aluminum carrier disk

with a pressure sensitive transfer adhesive. The

silicone on Silver was exposed to the environment.

Visual Inspection

The exposed material is transparent and shiny.

The shielded area is clear. At the intersection

of the shielded and exposed area, the coating

is less reflective (flat appearance). The exposed

area is tinted a faint yellow and is raised and

slightly convex.

High Magnification Inspection

Networks of cracks are visible at the edges of

the exposed area. Some large individual cracks

extend toward the center. Fine cracks in the

center are visible at high magnification.

ESCA Analysis

This is a silverized Teflon (FEP) with CV-1144-0

overcoating. The silver side had been exposed

to the oxygen erosion. Both the control and

the flight specimens contain carbon, oxygen,

and silicon. The concentrations of each element were approximately the same and the

chemical states of carbon were the same on

both specimens. This indicated that the exposure to space has no effect on the silver side.

Radiative Properties

The reflectance versus wavelength are shown

in Figure 13. The exposed material shows a

slight loss of reflectance. The integrated absorptance changed from 0.730 to 0.749. The control

sample emittance prior to flight was 0.896.

Physical Analysis

The mass loss of the sample was 0.00016 g.

The percentage of change when attributed to

the coating was 0.0089.

Oxygen Erosion

The reaction rate based on the above mass loss,

the AO fluence of 2.07 x 10 .20 atom/cm 2 is

9.8318 x 10 2s g/atom.

3.7 CV-2500 Silicone on Silver Coated Teflon

(Figure 14)

Sample Description

This sample was a clear, two component CV2500 silicone applied over a silver coated Teflon

(FEP) surface by brush. This silicone has extreme low outgassing properties and is used as

an embedding or potting compound where

good environmental protection for electronic

assemblies and components is essential.

Sample Configuration

The thickness of the sample coating was

0.1 371 6 cm and its mass was 0.07331 grams.

The Teflon (FEP) film was attached to an aluminum carrier disk with a pressure sensitive transfer adhesive. The silver side was exposed to

the environment.

Visual Inspection

The coating over the silver was transparent,

shiny and reflective. The shielded area was a

recessed, impressed line at an interface between

17
the shielded and the exposed areas. Approximately 1/4 x 1/4 cm chip of coating wasmissing (half from exposed area and half from

shielded area). The exposed area was raised

and slightly convex.

High Magnification Inspection

A visible crack in the surface of the exposed

area was more pronounced at the outer edges.

A break in the surface coating was exposed on

the subsurface layer; this exposure was in the

shielded region.

ESCA Analysis

This sample consists of a silver Teflon (FEP) with

CV-2500 silicone coating. The elemental compositions of the control and the flight specimens are carbon, oxygen, and silicon. The

concentrations of each element were the same

and the chemical states of carbon were the

same on both specimens. This indicates that

the exposure to space has no chemical effect

on the surface of the silver Teflon.

Radiative Properties

The reflectance versus wavelength is shown in

Figure (15). A slight loss of about 2-3% occurred throughout the scanned wavelengths.

The absorptance increased from 0.692 to 0.714.

The emittance of the control sample was 0.885.

Physical Analysis

The mass loss of the sample was 1.9 x 10 s g.

The percentage of mass change attributed to

the coating was 0.01 31.

Oxygen Erosion

The reaction rate based on the above mass loss,

the fluence of 2.07 x 102°and the sample's exposed area of 0.81072 cm 2 is 1.1325 x 10 .25g/

atom.

3.8 Teflon with Silver Coated Backing

(Figure 16)

Sample Description

This sample is a Teflon (FEP) film with a vapor

deposited silver coating on one surface.

Sample Configuration

The thickness of the sample is 0.1 071 88 cm

and its mass is 0.04860 grams. The Teflon (FEP)

sample was attached to an aluminum carrier

disk with a pressure sensitive transfer adhesive.

The Teflon (FEP) film was exposed to the environment.

Visual Inspection

The sample is reflective. The intersection of

shielded and exposed areas is recessed and

scratched.

High Magnification Inspection

There is no difference between the shielded area

and the control sample.

ESCA Analysis

The sample is a silver Teflon (FFP) film with the

Teflon side up. The control specimen has carbon and fluorine. The control specimen consists of mostly [-CF 2 - CF2-] bonds that are typical of Teflon surfaces. The flight specimen

which contains carbon, oxygen and fluorine,

shows some conversion of the [-CF2-CF2- ] bonds

to [-CF2-CFH- ] bonds.

Radiative Properties

The reflectance versus wavelength is shown in

Figure 1 7. The reflectance changed less than 6

percent from 600 to 2400 nm. The absorptance changed from 0.065 to 0.112. The emittance of the control sample was 0.793 originally and changed to 0.808.

18
Physical Analysis

The mass loss is 4.6 x 10 Sg. The change of the

coating mass was estimated at about 0.00288

percent.

Oxygen Erosion

The oxygen reaction rate based on the given

fluence, and the sample exposed area of

0.81073cm 2 is 2.7410x 10 .25g/atom.

3.9 Silver Coated Teflon (with center hole

cut-out) (Figure 18)

Sample Description

The silver coated Teflon (FEP) is a copolymer

film. This sample has a center hole cut out configuration for atomic oxygen effects on the surface edges.

Sample Configuration

The thickness of the sample was 0.10795 cm

and its mass was 0.04252 grams. The sample

was attached to an aluminum carrier disk with

an acrylic transfer adhesive. The silver surface

was exposed to the environment.

Visual Inspection

The interface between shielded and exposed

areas has a line, which is scratched and recessed.

The exposed area is slightly yellowed. A 1/2

cm diameter "hole" is cut at the center of the

sample.

High Magnification Inspection

The sample shows cracks around the 1/2 cm

diameter hole.

Spherical regions ringing the cracks are only in

the exposed region. At high magnification the

cracks appear superficial with possible deposits. Color of sample in these regions changes

from black to blue and then to tan.

ESCA Analysis

The sample is a silver Teflon with the silver side

up. This specimen has a 1/2 cm hole in the

center to study the edge effects near the opening. Three areas were analyzed: the control

specimen, near the inner edge on the flight

specimen, and away from the edge on the flight

specimen. The elemental compositions of the

three analyzed areas are as shown in Table 4

below.

Table 4. Elemental Composition of the Three Areas Analyzed on the Control

and Flight Samples

Flown Sample Flown Sample

Elements Control Sample Near Edge Away from Edge

C 80 atomic % 51 atomic % 54 atomic %

O 17 20 18

N 2 -- 12

Ag 0.4 10 6

Ni 1 3 3

Si -- 8 4

F -- 2 1

S -- 4 2

C1 -- 4 1

19
To determine whether the fluorine found on

the flight specimen is a surface contaminant or

from the Teflon layer that is below the exposed

silver surface, the two areas on the flight specimen were sputter etched. After the surfaces

were sputter etched, the fluorine concentration

increased by five times. This proves that the

Teflon layer which was underneath the silver is

very near the surface due to the erosion of the

silver layer. Thus, we can conclude that the

atomic oxygen eroded the silver, and this erosion is accelerated near the edge.

Radiative Properties

The reflectance vs. wavelength is shown in Figure 19. The reflectance was changed to less

then 1% from about 700 to 2400 nm while an

increase of the same amount is shown below

700nm. The absorptance changed from 0.550

to 0.546. The emittance of the control sample

was 0.059 to 0.062.

Physical Analysis

The mass loss was 0.00199g. The percentage

of mass change, based on the coating was

about 0.435.

Oxygen Erosion

The reaction rate based on the known fluence,

and the exposed area of 1.2429 cm 2is 1.189 x

10 _3g/atom.

3.10 CV-1144-0 Clear Silicone on Kapton H

Film (Figure 20)

Sample Description

The Kapton H, is a polyimide film, overcoated

with a one part silicone material which is specifically designed to .provide atomic oxygen

protection to the Kapton surface. The CV-1144-

0 silicone is a low outgassing dimethyl diphenyl silicone copolymer used for high and low

temperature applications.

Sample Configuration

The silicone thickness on the Kapton surface was

0.1 7297 cm and its mass was 0.09347 grams.

The Kapton was attached to an aluminum carrier disk by use of a pressure sensitive acrylic

transfer adhesive. The silicone was brush coated

to the Kapton and properly cured.

Visual Inspection

The surface is shiny and transparent. The

shielded area is recessed at the edge. The exposed area is raised above the retained area.

Tracks of raised and recessed areas exist between

the substrate and coating.

High Magnification Inspection

A network of cracking was visible at the outer

edge of the exposed area. Finer cracks were

visible near the center.

ESCA Analysis

This is a Kapton H film with a CV-1144-0 silicone coating. The control specimen had carbon, oxygen, and silicon. The 59% of carbon

is a C-O bond, and the remainder is 41% C-

(H,C) bonds. The 34% of silicon is in a form of

silicone, 42% is a SiOx, and 24% is SiO 2.

The flight specimen has carbon, oxygen, silicon, nitrogen, and a trace amount of tin. The

80% of carbon is a C--O bond, and the remainder is 20% C-(H,C) bonds. The 26% of silicon

is silicone, 56% is SiOx, and 18% is SiO 2. This

shows that some silicone on the surface of the

flight material has oxidized to form oxides. The

emerging nitrogen peak on the flight specimen

corresponds to Kapton which is under the silicone coating. Thus, we can conclude that the

atomic oxygen had oxidized some of the silicone and that the coating had been eroded.

20
Radiative Properties

Figure 21 shows the reflectance of the sample,

small changes on the order of 1-2% have occurred as a result of the exposure throughout

the range of the wavelengths. The absorptance

changed from 0.758 to 0.769. The emittance

of the control sample was originally 0.882

which increased to 0.91 4.

Physical Analysis

The mass loss of the sample was 4.46 x 10 .4 g.

The percentage of mass loss attributed to the

coating is 0.1196.

Oxygen Erosion

The reaction rate, based on the given fluence,

mass loss and the exposed area of 0.8107 cm 2

is 2.6575 x 10 .24g/atom.

3.11 CV-1142 Silicone Coating on Aluminum

(Figure 22)

Sample Description

This is a one part phenyl silicone sealant. It is a

non-corrosive, translucent, non-slumping, one

part moisture cured material specially designed

and processed for applications requiring extreme low temperatures, low outgassing and

minimal volatile condensable. This silicone is

usable for sealing, caulking, and is usable as an

adhesive.

High Magnification Inspection

The sample surface is slightly discolored within

the exposed area, which is barely visible at low

magnification. This variation may be mostly

due to linear marking at the edge of the supported region. High magnification shows no

change from the exposed to shielded regions.

ESCA Analysis

The control specimen of the CV-11 42 silicone

coating contains carbon, oxygen, and silicon.

The carbon on the surface contains C-(H,C)

bonds, and the silicon is 100% in the form of

silicone. The flight specimen has carbon, oxygen, silicon, and a trace amount of tin. The

flight specimen has a lower carbon concentration and higher oxygen and silicone concentration than the control. The chemical state of

carbon is the same as the control specimen,

but the silicon has 56% Si-O as in silicone and

44% is SiO 2. This indicates that some of the

silicone on the surface had been treated in space

to form SiO 2.

Radiative Properties

The reflectance of the sample shown in Figure

23 indicates a change of the absorptance from

0.564 to 0.592. A change of about 15% occurred at the lower wavelengths. The emittance of the control was 0.888, which increased

with time to 0.998.

Sample Configuration

The thickness of the silicone was 0.15113 cm

and its mass was 0.08847 g. The silicone was

applied directly to an aluminum carrier disk and

properly cured.

Visual Inspection

The sample surface is translucent and flat. The

shielded area is clear. The exposed area is tinted

and yellow/gray in Color.

Physical Analysis

The mass loss of the sample is 2.18 x 10 .4 g.

The loss attributed to the coating was about

2.6 x 1 0.3 percent.

Oxygen Erosion

The reaction rate, based on the exposed surface, was 1.299 x 10 .24g/atom.

21
3.12 CV-1500 Black Silicone on Aluminum

(Figure 24)

Sample Description

CV-1500 is a one part electrically conductive

phenyl silicone. It is non-corrosive, black in

color, non-slumping, and specially processed

for applications requiring low temperatures and

minimal volatile condensable under extreme

conditions.

Sample Configuration

The thickness of the silicone sample was

0.24409 cm and its mass was 0.21290 g. The

silicone was applied to the surface of an aluminum carrier disk and properly cured.

Visual Inspections

There were no visible differences between the

shielded and the exposed areas.

High Magnification Inspection

The exposed region is similar to the shielded

region with voids where the silicone was depleted.

ESCA Analysis

The sample is a black, electrically conductive

silicone coating called CV-1500. This specimen

showed identical behavior as the CV-1142 coating. The control specimen has carbon, oxygen, and silicon on its surface. The flight specimen had carbon, oxygen, silicon, and a trace

amount of tin. The carbon concentration is

lower and the oxygen and silicon concentrations are higher in the flight specimen than in

the control specimen. While the carbon bonding state remains the same, the flight specimen

shows more oxidized silicone than the control

specimen.

Radiative Properties

Figure 25 shows the reflectance versus wavelength for this silicone coating sample. The

absorptance changed from 0.931 to about

0.927. The reflectance remained below 10%

throughout the shown wavelength spectrum.

The emittance of the control was 0.880.

Physical Analysis

The mass loss of the sample was 3.75 x 104 g.

If attributed to the coating, the percentage loss

is 3.56 x 10 .3.

Oxygen Erosion

The reaction rate for the exposed area, based

the above loss, and fluence is 2.23452 x 10 .24

g/atom.

3.13 CV-2566 Red Silicone on Aluminum

(Figure 26)

Sample Description

The CV-2566 silicone is a two part, flowable,

red silicone specially processed for applications

requiring low temperatures, low outgassing and

minimal volatile condensables under extreme

operating conditions. This silicone is based on

a diphenyl dimethyl silicone used for sealing,

encapsulation, and as an adhesive.

Sample Configuration

The thickness of the silicone was 0.25806 cm

and its mass was 0.24561 g. The silicone was

applied directly to the surface of an aluminum

carrier disk and properly cured.

Visual Inspection

The color of CV-2566 was dark orange, shiny

and opaque. The shielded area has a convex

curvature. The exposed area is raised, sharply

convex, and cloudy, but less cloudy at the interface between the exposed and the shielded

areas.

High Magnification Inspection

The sample shows a crack network around the

outside diameter of the exposed area. The central portion shows mud cracks across the exposed region.

22
ESCA Analysis

The control specimen of this CV-2566 coating

had carbon, oxygen, silicon, and a small

amount of fluorine. Since fluorine is not a constituent in the CV-2566 composition and it is

present in a small amount, it is assumed to be a

surface contaminant. The chemical states of

carbon and silicon are typical of the silicone.

The flight specimen had carbon, oxygen, and

silicon. It also had the same chemical states of

carbon and silicon. No chemical changes were

detected on the flight specimen.

Radiative Properties

The absorptance of the coating changed from

0.679 to 0.695. The reflectance, as shown in

Figure 27, changed throughout the wavelength

by about one to two percent. The emittance

of the control sample was 0.899 changing with

time to 0.904.

Physical Analysis

The mass loss of the sample was 3.76 x 10 .4 g

and if attributed to the coating, the percentage loss of the coating was 1.873 x 10 .3.

Oxygen Erosion

The reaction rate of the coating, based on the

fluence and exposed area, is calculated to be

2.24048 E-24 g/atom.

3.14 X389-7 Beta Cloth on Aluminum

Backing (Beta Cloth Exposed) (Figure 28)

Sample Description

Beta cloth is tightly woven "beta" fiberglass

fabric having a light sizing to provide flexibility. A Teflon (PTFE) coating is applied to one

surface side of the fabric to provide abrasion

resistance and to meet non-combustible properties for an oxygen atmosphere. The other

side of the beta fabric has been coated with a

layer of vapor deposited aluminum for thermal

stability. The material is used in applications

for ESD and for thermal control.

Sample Configuration

The thickness of the beta cloth was 0.10972

cm and its mass was 0.04583 g. The beta cloth

PTFE surface was exposed to the environment.

The aluminum surface was attached with an

acrylic adhesive to the carrier aluminum disk.

Visual Inspection

The Beta cloth shows slight discoloration (yellowed) on its exposed surface.

High Magnification Inspection

Differences between the control and the exposed samples were evident.

ESCA Analysis

This is an aluminized beta cloth (X389-7), which

has the beta cloth side facing up. The flight

and the control specimens contain carbon, oxygen, fluorine, and a small amount of silicon.

The concentration of each element on the specimens are similar and the chemical state of the

carbon indicates that both surfaces are made

of Teflon coated beta cloth that are identical in

composition. No atomic oxygen effects were

observed.

Radiative Properties

There is an improvement in reflectivity as shown

in Figure 29. The absorptance changed from

0.277 to 0.281. The emittance of the control

sample was 0.873 and then 0.906 at the time

of the last measurement.

Physical Analysis

The mass loss of the sample was 2.6 x 10 .5 g.

The percentage change based on the Beta cloth

was 1.52 x 10 _.

Oxygen Erosion

The reaction rate, based on exposed area, was

calculated to be 1.549 x 10 .25g/atom.

23
3.15 CV-1144-0 Silicone on Beta Cloth

(Figure 30)

Sample Description

Beta cloth is a tightly woven "beta" fiberglass

fabric having a light sizing to provide flexibility. A teflon coating (PTFE) is applied to the

fabric surface to provide abrasion resistance and

to meet combustion specifications in an oxygen atmosphere. The other side of the beta

glass fabric has been coated with a layer of vapor deposited aluminum for thermal stability.

A thin layer of translucent CV-1144-0 silicone

coating has been applied to the Teflon surface

of the beta cloth for atomic oxygen protection.

Sample Configuration

The thickness of the beta cloth/CV-1144-0 silicone coating was 0.16383 cm and its mass was

0.1 0212 g. The thickness of the CV-1144-0 was

0.0283 cm. The sample was attached to an

aluminum carrier disk with an acrylic transfer

adhesive.

Visual Inspection

The Beta cloth is coated with a clear silicone

coating. The shielded area is visibly white with

an exposed "yellowed" area.

High Magnification Inspection

The sample is yellowed with surface crazing.

ESCA Analysis

The sample is a fiberglass cloth that is coated

with Teflon and then with CV-1144-0. The control specimen contains carbon, oxygen, and

silicon. This composition reflects the CV-1144-

0 layer. There was 62% of C-O bond and 38%

of C-(H,C). The silicon had 58% in Si=O and

42% in Si-O bonds. The flight specimen, on

the other hand, had carbon, oxygen, nitrogen,

and silicone. The carbon concentration decreased from 53 atom percent in the control

specimen to 43 atom percent; the oxygen concentration increased from 23 atom percent to

32 atom percent. The silicon concentration

remained the same. The chemical state of the

flight specimen shows that more silicon on the

flight specimen is oxidized to Si=0 bonds than

the control specimen.

Radiative Properties

The reflectance of the sample is shown in Figure

31. The absorptance of the exposed sample

changed from 0.410 to 0.459 and the emittance

of the control sample was 0.908 and later 0.922.

Physical Analysis

The mass change of the sample was 5.3 x 10 s

g. The percentage attributed to the coating

was 9.8 x 10 s.

Oxygen Erosion

The reaction rate based on the exposed area

was 3.158 x 1 02s g/atom.

3.16 Chemglaze Z-306 Polyurethane Paint

(Figure 32)

Sample Description

Chemglaze Z-306 is one part flexible polyurethane paint. The paint was a flat black absorptive polyurethane which fully cures by reacting

with moisture in about 10 days. The paint exhibits excellent abrasion resistance, low outgassing, and adhesive properties.

Sample Configuration

The thickness of the Z306 black paint was

0.09271 cm and its mass was 0.01 790 g. The

paint was applied directly to the aluminum carrier disk.

Visual Inspection

The shielded area of the paint is a flat black.

The exposed area is a "velvet" black.

24
High Magnification Inspection

The exposed region is darker and appears

smoother than the shielded, with striations.

ESCA Analysis

This is a polyurethane coating called Chemglaze

Z-306. Both the control and the flight specimen contain carbon, oxygen, nitrogen, and silicon on the surface. The flight specimen, however, has 30% less carbon, 14% more oxygen,

and 16% more silicon. The control specimen

has 7% of carbon in O-C = O bonds, 20% in CO bonds, and 73% in C-(H,C) bonds. The silicon on the flight specimen is highly oxidized.

The atomic oxygen has oxidized the silicon that

is on the surface.

Radiative Properties

The reflectance versus wavelength is shown in

Figure 33. The absorptance of the exposed

sample changed from 0.959 to 0.981. The emittance of the control sample was 0.912 and later

0.914.

Physical Analysis

The sample lost 3.32 x 10 .4 g. The percentage

loss of the coating was 3.28 x 10 2.

Oxygen Erosion

The oxygen reaction rate was 1.978 x 10 .24g/

atom, based on the exposed area and the given

fluence.

3.17. Ultem-lO00 (Figure 34)

Sample Description

Ultem-1000 is polyetherimide polymer material without glass fabric reinforcement. It is a

high performance material noted for its high

strength, long term high temperature heat resistance and electrical properties.

Sample Configuration

The thickness of the Ultem sample was 0.14859

cm and its mass was 0.09644 g. The sample

was attached to an aluminum carrier disk with

an acrylic transfer adhesive.

Visual Inspection

The shielded area of the sample was shiny, of

amber color, with minute bubbles on the outer

edge of disk. The exposed area was cloudy,

opaque, dull, with small triangular smudge

marks.

High Magnification Inspection

The exposed area of the Ultem was opaque.

The shielded region was transparent. The region had no discernible features at low magnification. High magnification showed etched

and a finely scratched surface.

ESCA Analysis

The sample was an amorphous thermoplastic

polyetherimide called Ultem-1000, often used

for molding structure. The control specimen

contains carbon, oxygen, nitrogen, silicon, and

trace amounts of chlorine, sulfur, and sodium.

The flight specimen showed the same four basic elements as the control specimen, but did

not show the trace elements. The carbon on

the control specimen consisted of 5% O - C =

O bond, 1 3% C-O bond, and 82% C - (H,C)

bonds. The carbon on the flight specimen had

12% C=O, 22%C- O, and 66%C-(H,C)

bonds. It appears that the exposure to atomic

oxygen altered the bonding state of the

polyetherimide to a more oxygenated state.

Radiative Properties

The change in reflectance was shown in Figure

35. The absorptance of the sample changed

from 0.596 to 0.659. The control emittance

was 0.897 and later 0.899.

25
Physical Analysis

The flight sample lost 1.157 x 10 _ g or 6.1 x

10 .2 percent of the original weight.

Oxygen Erosion

The reaction rate was 6.894 x 10 .24g/atom.

3.18 PEEK 45OG (Figure 36)

Sample Description

PEEK 450G is a Polyetheretherketone polymer

material. It is noted for its high temperature

applications, good abrasion and excellent

chemical resistance, and electrical properties.

Sample Configuration

The thickness of the sample was 0.12217 cm

and its mass was 0.05782 g. The sample was

attached to the carrier disk with a pressure sensitive acrylic transfer adhesive.

Visual Inspection

The shielded area of Peek 450G is shiny, clear

and taupe in color. The exposed area is cloudy,

dull and opaque.

High Magnification Inspection

The exposed surface is opaque and sand colored with little discernible morphology, even

at high magnification. The surface has a spotted, etched look with faint scratches.

ESCA Analysis

The flight and the control specimens contained

carbon, oxygen, nitrogen, and silicon. The

concentration of each element was the same

between the two specimens. The chemical

states of carbon were also the same. No

changes in the chemical composition were detected as the result of the exposure to space

environ ment.

Radiative Properties

The reflectance of the Peek sample dropped

about 5% throughout the explored wavelengths, as shown in Figure 37. The absorptance changed from 0.61 7 to 0.681. The emittance of the control sample was 0.880 and

eventually 0.894.

Physical Analysis

The sample loss was 9.71 x 10 .4 g, or as a percentage loss, it was 0.1 366.

Oxygen Erosion

The reaction rate of the PEEK was calculated to

be 5.78 x 10 .24g/atom based on the exposed

area.

3.19 CV-2500 Silicone on Kapton H Film

(Figure 38)

Sample Description

A two part, clear silicone, specifically designed

for applications requiring low outgassing and

minimal volatile condensables, was applied on

the Kapton surface.

Sample Configuration

The thickness of the silicone was 0.15189 cm

and its mass was 0.07679 g. The silicone was

applied to the Kapton surface after a proper

primer application. The Kapton was applied to

carrier substrate disk by a pressure sensitive

acrylic transfer adhesive. The thickness of the

Kapton is 0.0283 cm.

Visual Inspections

The shielded area of the silicone coated Kapton

was depressed. The exposed area of the substrate was crazed. The entire surface had a

uniform color and texture.

High Magnification Inspection

The sample included bubbles below the surface. The surface is crazed.

ESCA Analysis

The sample was a Kapton H film with a CV2500 silicone overcoating. The control and

26
flight specimenshad the same amounts of carbon, oxygen, and silicon on the surfaces. No

chemical changes were observed between the

control and the flight specimen.

Radiative Properties

The reflectance of the sample is shown in Figure 39. It showed small variations throughout

the scanned wavelength.

Physical Analysis

The mass loss of the sample was 3.03 x 10 .4g.

The percentage of coating loss was 3.39 x 10 2.

Oxygen Erosion

The reaction rate, based on the above mass loss

and the exposed area, was 1.805 x 10 .24g/atom.

3.20 Polyethersulfone 4800-G (PES)

(Figure 40)

Sample Description

Victrex PES is a transparent Polyethersulfone

polymer material having exceptional mechanical properties, high temperature, and excellent

electrical properties over a varying temperatures

range. The PES is commonly used in medical

applications because of its excellent resistance

to sterilization methods.

Sample Configuration

The thickness of the sample was 0.14935 cm

and its mass was 0.09954 g. The sample was

attached to an aluminum carrier disk with an

acrylic pressure sensitive transfer adhesive.

Visual Inspections

The shielded area of the sample was clear, with

a light brown tint. The exposed area was

opaque, cloudy and tan.

High Magnification Inspection

The exposed area was opaque and yellowed.

ESCA Analysis

The sample was a Polyethersulfone called

Victrex PES4800G. The flight and control specimens contained carbon, oxygen, nitrogen, silicon, and sulfur. There was a slight decrease in

carbon concentration and increase in oxygen

concentration. While the control specimen

consisted of 96% C - (H,C) bonds and 4% C -

O bonds, the flight specimen had 28% of C -

(H,C),18%C---O, 53%O-C=O. Since the

Polyethersulfone primarily consists of C - C and

C - O bonds, the C = O and O - C = O bonds

detected on the flight specimen reflect the

transformed composition from the atomic oxygen exposure.

Radiative Properties

The changes in reflectance produced by the

flight are shown in Figure 41. The absorptance

increased from 0.539 to 0.619. The emittance

of the control sample was 0.889 and eventually 0.895.

Physical Analysis

The exposed sample lost 9.41 x 10 .4 g and, in

terms of coating of percentage loss, about 2.10

x 10 3.

Oxygen Erosion

The oxygen erosion rate of the exposed area

was 5.607 x 10 .24g/atom.

3.21 Polymethylpentene (TPX) Film

(Figure 42)

Sample Description

Polymethylpentene (TPX) is a transparent film

having excellent electrical, chemical and high

temperature properties. It is said to possess the

lowest specific gravity of any known thermoplastic. It is commonly used for cable and wire

wrap.

2/
Sample Configuration

The thickness of the sample was 0.14605 cm

and its mass was 0.06735 g. The TPX film was

attached to an aluminum carrier disk with a

pressure sensitive acrylic transfer adhesive.

Visual Inspections

The sample shielded area was clear and shiny.

The exposed area was cloudy and opaque.

High Magnification Inspection

The exposed film was clouded.

ESCA Analysis

The sample material was a molding structure

made of polymethylpentene. The control specimen was carbon, oxygen, and a trace amount

of sulfur. The 66% of carbon was in C - O bond

and the other 34% was the C - (H,C) bonds.

The flight specimen, however, had carbon, oxygen, and small amounts of nitrogen and silicon. As with other specimens, the carbon concentration decreased and the oxygen concentration increased on the flight specimen from

the control specimen. However, these changes

in elemental composition are small and not reflected in the carbon bonding state. The chemical state of carbon on the flight specimen was

similar to the control specimen.

Radiative Properties

The changes in reflectance of the exposed

sample are shown in Figure 43. Its absorptance

changed from 0.489 to 0.540. The emittance

of the control sample was 0.856 and later

0.873.

Physical Analysis

The sample lost 8.41 x 1 0.4 g. In terms of percentage loss in thickness, it was 0.11 89.

Oxygen Erosion

The oxygen reaction rate, based on the sample

exposed area, was 5.01 x 1 0.24g/atom.

3.22 3M Pressure Sensitive Tape No. 5

(Figure 44)

Sample Description

3M Scotch Brand Electrical Tape 5 is a one rail,

transparent polyester film with a thermosetting,

pressure-sensitive acrylic adhesive. It was a

single coated tape featuring an acrylic adhesive system that offers excellent resistant to most

common solvents and hydraulics fluids. It has

excellent electrical properties, and good adhesive strength to most surfaces.

Sample Configuration

The thickness of the sample was 0.0889 cm and

its mass was 0.00829 g. The tape was attached

directly to an aluminum carrier disk with its own

adhesive.

Visual Inspections

The shielded area of the tape was flat and transparent. The exposed area was gray, opaque

and slightly darker with a gray spot off the center. No discernible morphology was apparent

at low magnification.

High Magnification Inspection

The tape had a translucent surface with a gray

layer in the exposed region. High magnification showed an etched surface.

ESCA Analysis

The sample was a polyester tape and was identified as 3M tape #5. The flight and the control specimen both have carbon, oxygen, nitrogen, and a small amount of silicon. There

was less carbon and more oxygen on the flight

specimen than the control specimen. The

chemical states of carbon of both specimens

also reflect the difference in carbon and oxygen concentration. The carbon in the control

specimen is O - C = O, C - O, and C - (H,C)

bonds. The carbon in the flight specimen was

in C = O, C - O, and C - (H,C) bonds.

28
Radiative Properties

Figure 45 shows the sample changes in reflectance from 300 to 2400 mm. The loss was close

to 10% in most of the region. The absorptance

changed from 0.434 to 0.523. The control

emittance was 0.735 and eventually changed

to 0.751.

Physical Analysis

The tape mass loss was 1.062 x 10 .3 g and the

thickness change was about 1.114 percent.

Oxygen Erosion

The reaction rate was calculated to be 6.328 x

10 .24g/atom.

3.23 Uralane 5750LV-A/B (Figure 46)

Sample Description

Uralane 5750 (Diphenylmethane disocyanate/

Polyols in Solvent) is a translucent, soft, two

part, polyurethane conformal coating designed

specifically for insulating printed circuit boards

and electronic components. The material exhibits excellent resistance to heat as well as

humid conditions. As a cured coating, it has

very low outgassing and condensable properties for use in outer space and high vacuum

environments.

Sample Configuration

The thickness of the sample was 0.11201 cm

and its mass was 0.19765 g. The coating was

applied directly to the surface of an aluminum

carrier disk.

Visual Inspections

The shielded area of the Uralane Coating was

transparent and shiny. The exposed area was

cloudy, dull and opaque.

High Magnification Inspection

The sample exposed region was opaque and

grayish in color.

ESCA Analysis

The sample was a Uralane 5750 LV A/B coating. Both the control and flight specimens had

carbon, oxygen, nitrogen, and silicon. However, the concentrations of these elements on

the flight specimen differ from the control specimen. The flight specimen had slightly less carbon and nitrogen, while having more oxygen

and silicone. The chemical state of carbon on

the control specimen was 67% C-(H,C), 26%

C-O, and 7% O-C--O. The carbon on the flight

specimen was bonded 58% C-(H,C), 34% CO, and 8% C--O.

Radiative Properties

Figure 47 shows the reflectance changes of the

Uralane sample. Losses in reflectance of the

order of 7-8% have occurred over the entire

analyzed wavelengths. The absorptance

changed from .558 to .648. The emittance of

the control sample changed from .843 to .878

during the interval of the measurement.

Physical Analysis

The mass loss was 1.48 x 10 .4 g with a change

in coating thickness of about 0.1046 percent.

Oxygen Erosion

The reaction rate for the sample, based on the

exposed area, was 8.8188 x 10 .25g/atom.

3.24 Uralane 5753 LVoA/B (Figure 48)

Sample Description

Uralane 5753 (Aromatic Disocyanate/Hydroxy

Terminated Polyols) is a translucent amber,

100% solid, two part polyurethane encapsulant and coating material, which, when cured,

provides excellent electrical insulation and hydrolytic stability to electrical and electronic components.

Sample Configuration

The thickness of the sample was 0.12877 cm

and its mass was 0.033879 g. The Uralane
material was applied directly to the surface of

the aluminum carrier disk.

3.25 Epon 828/Versamid 140/Titanium Dioxide (Figure 50)

Visual Inspections

The shielded area of the Uralane 5753 was shiny.

The exposed area was cloudy, dull and opaque.

High Magnification Inspection

The exposed region of the sample was grayish

and opaque with no visible features. The

shielded region had a clear appearance.

ESCA Analysis

This is a Uralane 5753LV-A/B over coating on

an aluminum substrate. Both specimens, flight

and control, consisted of carbon, oxygen, nitrogen and silicon. The reference specimen also

contained a small amount of fluorine. When

the surfaces are sputter etched, the silicon and

fluorine concentrations decreased, indicating

that they reflect only surface compositions. The

chemical state of carbon on both specimens

showed similar bonding states that correspond

to polyurethane. There is no chemical change

in the Uralane coating as a result of the space

exposure.

Sample Description

Epon 828 is an undiluted clear difunctional

Bisphenol A/epichlorohydrin derived liquid epoxy resin. The Versamid 140 is a medium viscosity, reactive polyamide resin, based on

dimerized fatty acid and polyamines. The Epon,

when cross linked, or hardened with an appropriate liquid curing agent will provide excellent mechanical and adhesive properties. A

white titanium dioxide pigment has been added

for application identification.

Sample Configuration

The thickness of the sample was 0.10261 cm

and its mass was 0.02650 grams. The epoxy

sample was adhesively bonded directly to the

surface of an aluminum carrier disk.

Visual Inspection

The shielded area of the Epon 828 with

Versamid 140 and Ti02 was pale yellow and

shiny. The exposed area was white, dull, with

dirt specks with metallic flakes.

Radiative Properties

Figure 49 shows that the sample reflectance loss

occurred mainly between 300 and 1400 nm.

The absorption increased from 0.612 to 0.651.

The emittance of the control sample changed

from 0.880 to 0.912 during the measurement

period.

Physical Analysis

The sample mass loss was 4.8 x 10 .5 g and the

percentage of change was about 3.67 x 10 .2.

Oxygen Erosion

The reaction rate was calculated to be 2.8601

x 10 .25 g/atom.

High Magnification Inspection

The exposed area of the sample was white while

the shielded region was slightly yellowish. High

magnification showed the exposed area was less

smooth and had a "frosted" appearance.

ESCA Analysis

The sample was an epoxy 828 with Versamid

140 curing agent and with Ti02 pigment. The

control specimen contained carbon, nitrogen,

silicon, and oxygen. The 44% of carbon is C =

O, 27% is C - O and 29% is C - (H, C). The

flight specimen had carbon, oxygen, aluminum

and silicon. The flight specimen had substantially less carbon, 37 atomic % as opposed to

3O
77 atomic %. It showed an increasein oxygen, 47 atom % from 11 atom %, and in silicon concentration. Therewas somealuminum

on the flight specimenthat was transferredfrom

the aluminum sample tray. The Ti02coating

was not detected. The chemical state of carbon on the flight specimen was 62% O-C--O

and 38% C-(H,C). The atomic oxygen hasaltered the chemical state of this material.

Radiative Properties

The reflectance of the sample decreased about

10% between 400 and 1600 nm, as shown in

Figure 51. The absorptance changed from

0.212 to 0.289 and the emittance of the control changed from 0.905 to 0.898 during the

measurement period.

Physical Analysis

The sample mass loss was 1.65 x 10 .4 g with a

mass loss of 2.685 x 10 .2 percent.

Oxygen Erosion

The oxygen reaction rate was 9.831 x 10 .25x g/

atom.

3.26 Aluminized Beta Cloth X389-7

(Aluminized Exposed (Figure 52)

posed environment. The cloth was attached

to the aluminum carrier disk by use of a pressure sensitive acrylic transfer adhesive. The aluminum surface faced the environment.

Visual Inspections

The sample was an aluminized textured, glass

fabric cloth that was uniformly woven.

High Magnification Inspection

The metallization on the cloth was missing from

the uppermost surface of several fiber bundles.

ESCA Analysis

The sample was an aluminized beta cloth X389-

7 with the aluminum side exposed to space.

The control specimen consisted of carbon, oxygen, nitrogen, silicon, flourine, aluminum, and

a trace amount of sodium. The 95% of carbon

was hydrocarbon, while 5% was fluorocarbon.

The flight specimen contained carbon, oxygen,

silicon, calcium, fluorine, aluminum and sodium. The carbon and fluorine concentration

decreased, and the oxygen, aluminum, and silicon concentration increased on the flight specimen. Only hydrocarbon was detected on the

flight specimen. The sources for calcium, sodium, and nitrogen are not known at this time.

Sample Description

Beta Cloth is a tightly woven "beta" fiberglass

fabric having a light silene sizing to provide flexibility. A Teflon (PTFE) coating was applied to

one surface to provide abrasion resistance and

to meet combustion properties in an oxygen

atmosphere. The other side of the beta glass

fabric had been coated with a layer of vapor

deposited aluminum for thermal stability. The

material is used in applications for ESD and thermal control.

Radiative properties

As shown in Figure 53, the reflectance of the

flight sample changed about one percent

throughout the measured wavelengths. The

absorptance changed from 0.263 to 0.266 and

the emittance of the control sample remained

at 0.1 25.

Physical Analysis

The sample gained 0.2 x 10 s g or 1.2 x 10 .2

percent of the original mass.

Sample Configuration

The thickness of the beta cloth was 0.11125

cm and its mass was 0.46756 g. The aluminized surface of the beta cloth faced the exOxygen Erosion

The reaction rate, based on exposed area, the

mass gained and the oxygen fluence, was calculated to be 7.15 x 10 2_ g/atom.

31
4.0 Analysis of Results

The morphological changes resulting from the

exposure of the 25 samples to atomic oxygen

and other space effects are shown in Table 3.

The table shows for each sample described in

the preceding pages the following:

Oxygen reaction efficiencies in terms of mass

loss/atomic oxygen, based on the total area

or the exposed area of the sample.

• The reflectance of the sample before and

after environment exposure.

• The absorptance before and after with the

respective percentage change.

The emittance for the control sample (the

non-exposed) was measured at a distance

of several months apart.

The approximate density of the exposed

materials was taken from literature or the

manufacturer's catalogs.

The reaction rate efficiencies of test materials

can be grouped as follows: the least affected

in terms of the erosion have efficiencies from 1

x 10 .25to 10 x 102s (g/atoms). This group includes 9 samples, of which 3 are silicones, 2

are epoxies, 2 are Uralane and one of each, a

beta cloth and a Teflon.

A second group has efficiencies varying from

10 x 1 02s to about 43 x 10 -2s,and it includes 9

materials consisting of 8 silicones and the polyurethane Z-306 Chemglaze black paint. This

group includes the commonly referenced reaction efficiency of Kapton (3 x 1024cm3/atom

or 4.26 x 10 .24 g/atom when the Kapton density is taken to be 1.42 g/cm3).

A third group, with efficiencies from 50 to 69 x

10 2s includes 5 organic samples: Pentene, one

sulfone, one PEEK, 3M tape and one Ultem.

A single material, Delrin II, had the largest erosion efficiency, 1 79 x 10 2s g/atom.

Three materials, Aluminum beta cloth X389-7,

Epoxy fiberglass G1 1, and CV-1 144 Siclicone

on Delrin, had an increase in mass which could

be translated in a positive reaction rate of about

7 x 10 -26,4 x 10 -24,and 4.35 x 10 24, respectively.

The fiberglass sample showing this behavior is to

be compared to a similar fiberglass sample (SP-4)

which included a fire retardant component and

has an erosion efficiency of 5.9 x 10 2_ g/atom.

The spectral reflectances of these samples,

measured before and after the flight using a

(P.E.) _,-9 spectrophotometer, are shown on the

respective figures. The figures list the integrated

absorptances of the samples before and after

flight exposure and two values of the emittance

for the non-exposed control sample. These

values for the non-exposed samples were taken

at a time interval of several months from each

other. The emittances of the flown samples

could not be measured because of their physical sizes.

Table 3 shows the percentage of change of the

absorptances. The percentage of change for

the sample EPON 828 Versamide 140

amounted to a value as large as 36%. Two

samples CV-2500 silicone on Kapton H film and

CV-1500 black silicone show a small absorptance change (less than one percent). These

thermo-optical changes reflect the sample coating thickness (on the order of 2 to I 0 x 10 .3in,

as indicated in the sample description) and the

nature of the substrates.

Table 3 also lists a coating material density value.

This value was taken from manufacturers' catalogs or from literature. It may be used to obtain approximate values of the volume reaction

efficiency (cm3/atom). The actual density may

be somewhat different because of the sample

preparation, the layering of the coating, voids

32
and other factors employed on the application

of the coating.

5.0 Conclusions

Twenty-five material samples, mostly polymeric

coatings, varying in the thicknesses between 2

and 10 x 1013in., were attached to aluminum

disc substrates and mounted in a tray and carried aboard the STS-46 Atlantis shuttle. They

were exposed to the shuttle bay environment

at an orbit of 228-230 km and at a 28 ° inclination. The exposure of these coating samples in

space complemented several other tests on the

effect of the atomic oxygen and space environment on materials and the measurement of

the environment in the shuttle bay in space.

The exposure of those coatings to the induced

gaseous plasmas, radiation, and to a ram oxygen fluence of 2.07 x 102o atom/cm 2 resulted

in their erosion and morphological changes.

Those changes have been verified using XPS

analysis, microscopic observations, and thermooptical measurements. The results have been

tabulated. The measured reaction efficiencies,

based on the mass loss expressed in grams of

materials removed per oxygen atom, have been

reported. The results show that the reaction

efficiencies of the materials reported here can

be grouped in about three ranges of values.

The least affected materials with efficiencies

varying from 1 D25 to 10E-25 (g/atom) include

silicone, epoxies, Uralane and Teflon. A second group from about 10E -25 to 45 E-25 includes additional silicones coatings and includes

the Z-306 Chemglaze paint. This range of values includes the Kapton which is commonly

reported to have an efficiency of 42.6 x 10 .25

(g/atom). The third range from 50 to 75E-25

includes organic compounds such as Pentene,

PEEK, Ultem, Sulfone and 3M tape. A Delrin

sample indicated the highest reaction (1 79 x

10 .25) and three samples showed a slight increase in mass rather than loss. The thermooptical changes in absorptance and reflectances

resulting from the exposure have been reported. A few samples suffered considerable

changes in absorptance.

6.0 Acknowledgments

We wish to thank J. Townsend, W. Peters, F.

Gross, J. Colony, and J. Benavides who have contributed either in the submission of samples to

be exposed or to the analysis of the experimental results. Special thanks to L. Leger of the

Johnson Space Center (JSC) for providing us

space in the EOIM-III experiment.

7.0 References

1. Leger L., S. L. Koontz, and J. Visentive, An

Overview of the Evaluation of Oxygen Interaction

with Materials - Third Phase (EOIM-III) Experiment: Space Shuttle Mission 46, AIAA-93-0497,

31 st Aerospace Science Meeting and Exhibit,

January 11, 1993, Reno, Nevada.

2. Koontz S. L., J. Leger, et al., Oxygen Interaction With Materials III - Mission and Induced Environments Journal of Spacecraft and Rocket,

Vol 32 No. 3, May-June 1995.

3. Scialdone, J. J., C. H. Clatterbuck et. al.,

Evaluation of Certain Material Films Flown on

EOIM III, NASA TM 104621, GSFC, Sept. 1 995.

4. Banks, B., S. K. Rutledge, J. A. Brady, and J.

E. Merrow, Atomic Oxygen Effect of Materials,

NASA Conference Publication 3035 Part 1,

NASA Langley, June 28, 1988.

33

FIGURES

35
Figure 2. CV-1144-0 Silicone on Delrin--Left, flight sample; right, control sample

100 I I I I I I I I I I I I

90

8O

70

_'60 " _'-_

oZ -/ w,j_

_ 50

..JW -- /

u. 40 "'

ft. - //

30

20 -//

10

0 I I I I

200 400 600 800 1000

SAMPLE: PRE-FLIGHT A = 0.401

(SP1) POST-FLIGHT A = 0.492

FILE# 1970_C

i

• _ PRE-FLIGHT

i

- POST-FLIGHT

_7

I I I I 1 I I

1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.926 5NOV1991

E = 0.912 10MAY1993

Figure 3. CV-1144-0 Silicone Coating on Delrin --Reflectance vs. Wavelength

36
Figure 4. CV-2500 Silicone on Delrin--Left, flight sample; right, control sample

100 I I I I I I I I I I I I

90

PRE-FLIGHT

70!80 _'_ _ _ POST-FLIGHT

_. 40

_° _

10

m

0 i

200

SAMPLE:

(SP2)

V •

I I I I I I I I I _ I

400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

WAVELENGTH (nm)

PRE-FLIGHT A = 0.394 CONTROL SAMPLE: E = 0.929

POST-FLIGHT A = 0.466 E = 0.920

FILE# 1970_C

Figure 5. CV-2500 Silicone Coating on Delrin

2600

5 NOV 1991

12 MAY 1993

3/
Figure 6. Delrin II 900--Left, flight sample; right, control sample

1O0

9O

I I I I I ! I I I

7O

LU 60 °

Z - \/ <

_- 50

=40 I U

30

m

20

10

0 I

200

SAMPLE:

(SP3)

FILE# 1970_.C

I

400 600

I

8OO

PRE-FLIGHT

POST-FLIGHT

I l I

m

PRE-FLIGHT

" POST-FLIGHT

1\

Figure 7.

v

I I I I I I I

1000 1200 1400 1600 1800 2000

WAVELENGTH (nm)

A = 0.384 CONTROL SAMPLE: E = 0.910

A = 0.403 E = 0.895

m

2200 2400 2600

5NOVl_1

8FEBI_3

Delrin II 900--Reflectance vs. Wavelength

38
Figure 8. Epoxy FiberglassG-11 (FlameRetardant)--Left, flight sample; right, control sample

100 I I I I I i I I I I I I

9O

80

7O

L_ 60

0

Z

<

_- 50

o

uJ

_ 40

UJ

II -

30

20

10

0

200

i

PRE-FLIGHT

1

-- pO,C_T.FLIGHT

SAMPLE:

(SP4)

//

j// \

/,i %\

2J

I I I I I I I I I I i i

400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

PRE-FLIGHT A = 0.643 CONTROL SAMPLE: E = 0.906 6 NOV1991

POST-FLIGHT A = 0.657 E = 0.903 22JUN1993

FILE# 1970 E

Figure 9. Epoxy Fiberglass G-11 (Flame Retardant)--Reflectance vs. Wavelength

39
Figure 10. Epoxy FiberglassG-11, No FlameRetardant--Left, flight sample;right, control

sample

IO0

9O

8O

7O

uJ 60

(..)

z

I--- 50

_O

uJ

..I

u. 40

uJ

n30

20

10

0

200

I I I I I I I I I I I I

B

-- PRE-FLIGHT

POST-FLIGHT

/

I/

! I I

400 600

I

800 1000

SAMPLE: PRE-FLIGHT A = 0.692

(SPS) POST-FLIGHT A = 0.720

f--

\

I I I I I I I I

1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH {nrn)

CONTROL SAMPLE: E = 0.910 6NOV1991

E = 0.908 2s MAR1993

FILE# 1970_E

Figure 11. Epoxy Fiberglass G-11, No Flame Retardant--Reflectance vs. Wavelength

40
Figure 12. CV-1144-0 Silicone on SilverCoated Teflon--Left, flight sample; right, control

sample

100

9O

80

70

w 60

(.D

z

<

I- 5O

(DIJJ

u_ 40

I..IJ

or"

I I I I I I I I I I I I

m

30

20

0 i l i

200 400 600 800

n

PRE-FLIGHT

-- POST-FLIGHT m

jr

m

I

1000 2600

I I I I I I I

1200 1400 1600 1800 2000 2200 2400

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.730 CONTROL SAMPLE: E = 0.896 7 NOV199_

(W22) POST-FLIGHT A = 0.749 E = 0.909 22JULt993

FILE# 1970 G

Figure 1 3. CV-1144-0 Silicone on Silver Coated Teflon--Reflectance vs. Wavelength

41
Figure 14. CVo2500 Silicone on SilverCoated Teflon--Left, flight sample;right, control

sample

I00

90

I I I I I I I I I I I I

m

80 _ PRE-FLIGHT

= -- POST-FLIGHT

70

w 60 /'

°Z

<

_ t

_- 50

0

._1

u_ 40

30 _

_

20

. .,/@>1 _

-f

lO /

0 i i i I I

200 400 600 800 1000

I I I I I I I

1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0,692 CONTROL SAMPLE: E - 0.885 7 NOV1_1

(W23) POST-FLIGHT A = 0.714 E " CONTROL N/A 22JUL1_93

FILE# 1970._G

Figure 15. CV-2500 Silcone on Silver Coated Teflon--Reflectance vs. Wavelength

42
Figure 16. Teflon with SilverCoated Backing--Left, flight sample;right, control sample

100

90

80

70

w 60

(D

z

5O

0

IJJ

u_ 40

i.u

rc

3O

2O

i

10

0

2OO

SAMPLE:

(W24)

- /,

II

I

i

PRE-FLIGHT -

-- POST-FLIGHT m

m

I I I I I I I I I I I

400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

PRE-FLIGHT A = 0.065 CONTROL SAMPLE: E = 0.793 31OCT1991

POST-FLIGHT A = 0.112 E ---- 0,808 12MAY1993

FILE# 1970b

Figure 1 7. Teflon with Silver Coated Backing--Reflectance vs. Wavelength

43
Figure 18. Silver Coated Teflon with Center Hole Cut-out--Left, flight sample;right, control

sample

100

9O

8O

I I I I I I I I I I I I

m

7O

w 60

(_)

z

_- 50

(.)

IJJ

.d

u_ 40

W

rr

30

i

2O

10

0

200

/'/

J

I I I I I I I I I I

400 600 800 1000 1200 1400 1600 1800 2000 2200

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A=0.550 CONTROL SAMPLE: E=0.059

(W25) POST-FLIGHT A = 0,546 E = 0.062

FILE# 1970 K

Figure 19.

PRE-FLIGHT

POST-FLIGHT

m

I I

2400 2600

5 NOV 1991

21 SEP 1993

Silver Coated Teflon with Center Hole Cut-out--Reflectance vs. Wavelength

44
Figure 20. CV-1144-0 Clear SiliconeCoating on Kapton H Film--Left, flight sample; right

control sample

1 O0 I I I i I I I I I I I I

9O

8O

7O

w 60

0

z

<i: I- 5O

o

L.U

...J

u_ 40

I.U

rr

m

PRE-FLIGHT

POST-FLIGHT m

.o10 - ) _

0 I i ! I I I I I I I I

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.758 CONTROL SAMPLE: E = 0.882

(W26) POST-FLIGHT A = 0.769 E = 0.914

m

I

2600

7 NOV 1991

22 JUL 1993

FILE# 1970 F

Figure 21. CV-1144-0 Clear Silicone Coating on Kapton H Film--Reflectance vs. Wavelength

45
Figure 22. CV-1142-0 Silicone Coating on Aluminum --Left, flight sample; right control

sample

100

90

8O

7O

LU 60

(..)

Z

<

I-- 50

O

LLI

LL

ILl

ec

I I I I I I I I I I I I

f

_//

3O

2O

10 '

m

0 I I I I

200 400 600 800 1000

SAMPLE: PRE-FLIGHT A = 0.564

(W27) POST-FLIGHT A = 0.592

FILE# 1970B

m

PRE-FLIGHT

-- POST-FLIGHT

m

I I I I I I I I

1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.888 31OCT1991

E = 0.998 12MAY1993

Figure 23. CV-1142 Silicone Coating on Aluminum--Reflectance vs. Wavelength

46
Figure 24. CV-1500 Black Silicone on Aluminum--Left, flight sample; right, control sample

100 I I I I I I I I I I I I

m

9O

80

7O

w 60

0

z

I- 50

o

w

.,..I

w 40

LI.I

rr

3O

2O

m

PRE-FLIGHT

POST-FLIGHT

B

10

_ :,._ _ _..-.. --_

I I I I

0

200 400 600 800 1000

I I I

2200 2400 2600

I I I I I

1200 1400 1600 1800 2000

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.931 CONTROL SAMPLE: E = 0.880 7Nov199_

(W28) POST-FLIGHT A = 0.927 E = N/A 22JULY1993

F_LE# 1970 G

Figure 25. CV-1500 Black Silicone on Aluminum--Reflectance vs. Wavelength

4/
Figure 26. CV-2566 Red Silicone on Aluminum--Left, flight sample; right, control sample

100

90

8O

7O

., 60

0

Z

_ 50

w

u_ 40

IJ.I

rr

___ I I I I I I I I I I I I --

m

PRE-FLIGHT

POST-FLIGHT

I

X-.-,

3o

20 r

0 I I I I

200 400 600 800 1000

i

I

2600

I I I I I I i

1200 1400 1600 1800 2000 2200 2400

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0,679 CONTROL SAMPLE: E = 0.899 7Novl_t

(W29) POST-FLIGHT A = 0.695 E = 0.904 22JUL1993

FILE# 1970F

Figure 27. CV-2566 Red Silicone on Aluminum--Reflectance vs. Wavelength

48
Figure 28. X389-7 BetaCloth on Aluminum Backing(BetaCloth Exposed)--Left, flight

sample; right, control sample

100 I I I I I I I I I I I I

_.

PRE-FLiGHT

go m

POST-FLIGHT

8O

,,, 60

O

z

1-- 50

O

IJJ

_,J

u_ 40

IJJ

rr"

3O

20

II '/

10

0 J

20O

SAMPLE:

(x111

FILE# 1970 0

Figure 29.

m

I I I I I I I I I I I

400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

PRE-FLIGHT A -- 0.277 CONTROL SAMPLE: E = 0.873

POST-FLIGHT A = 0.281 E = 0.906

5 NOV 1991

1 AUG 1993

X389-7 Beta Cloth on Aluminum Backing (Beta Cloth Exposed)--Reflectance vs.

Wavelength

49
Figure 30. CV-1144-0 SiliconeX389-7 on BetaCloth--Left, flight sample;right, control

sample

100 I I I I I I I I I I I I

D

90

80

20

m

PRE-FLIGHT

- POST-FLI(IHT u

70

o_

;60 ._,-_ , _v,

5O o /

EL 40

"' / _

j/ \\

-/J '_

10 v

0 I I I I I I I I I I I

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.410 CONTROL SAMPLE: E = 0.908 5 NOV1_1

(X12) POST-FLIGHT A = 0.459 E = 0.922 16FEB1993

FILE# 1970_D

I

2600

Figure 31. CV-1144-0 Silicone X389-7 on Beta Cloth--Reflectance vs. Wavelength

50
Figure 32. Chemglaze Z-306 Polyurethane Black Paint--Left, flight sample; right, control

sample

I O0 I I I I I I I I I I I I

90

80

7O

w 60

o

z

<

_. 50

(9

iJJ

.,..J

u. 40

W

or"

3O

B

20

10

i

PRE-FLIGHT

-- POST-FLIGHT i

i'4-'--_ _ _"_-- : : : l' ." i i0

200 400 600 800 1000 1200 1400 1600 1800 2000 2200

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.959 CONTROL SAMPLE: E = 0.912

(X13) POST-FLIGHT A = 0.981 E = 0.914

FILE# 1970 H

-" I

2400 2600

28 JAN 1991

19 FEB 1993

Figure 33. Chemglaze Z-306 Polyurethane Black PaintmReflectance vs. Wavelength

51
Figure 34. Ultem-lOOO--Left, flight sample; right, control sample

100

90

8O

7O

w 60

o

z

<

I-- 5O

c.)

w

,,--I

u._ 40

LU

rr"

I I I I I I I I I

I I I

' _ PRE-FLIGHT

-- POST-FLIGHT m

_ ,//"

3O

- //

20 _

0 I I I

200 400 600 800

SAMPLE: PRE-FLIGHT

(X35)

FILE# 1970_ E

I

1000

A = 0.596

POST-FLIGHT A = 0.659

f_.. A

I I I I I I I i

1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.897

E = 0.899

6 NOV 1991

26JUL 1993

Figure 35. Ultem-lOOO--Reflectance vs. Wavelength

52
Figure 36. PEEK450G--Left, flight sample;right, control sample

100 I I I I I i I i I

9O

80

7O

m 60

(.b

z

<

I- 5O

(J

UJ

,_.J

u.. 40

W

n"

3o

2O

-,,,//

10 _

I I I

m

PRE-FLIGHT

-- POST-FLIGHT m

0 I I

200 400

SAMPLE: PRE-FLIGHT A=0.617

(X36) POST-FLIGHT A = 0.681

j

\

! I I I I I I I I I

600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.880 30OCT1_1

E = 0.894 1SEP1993

FILE# t970 1

Figure 37. PEEK 450G--Reflectance vs. Wavelength

53
Figure 38. CV-2500 Silicone on Kapton H Film--Left, flight sample;right, control sample

100

9O

8O

70

o_

u.i 60

o

z

<

t- 5O

o

Iii

,,_1

u_ 40

III

IT

30

20

10

0

2O0

I I I I I I I I I I I I

PRE-FLIGHT -

-- POST-FLIGHT

m

J

/

400 600 800

,- \1 \\

"-' \

I

2600

J I I I I I

1000 1200 1400 1600 1800 2000

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.661 CONTROL SAMPLE: E = 0.921 6 NOV1_1

(X38) POST'FLIGHT A = 0.655 E = 0.914 24FEe1993

I I

2200 2400

FILE# 1970 E

Figure 39. CV-2500 Silicone on Kapton H Film--Reflectance vs. Wavelength

54
Figure 40. Polyethersulfone4800-G (PES)--Left,flight sample; right, control sample

100 I I I I I I I I I I I I

9O

80

PRE-FLIGHT

-- POST-FLIGHT

m

m

m

7O

w 60

_ _ __7_ _

u_ 40

30 /

'I/ 7 - - / .X -

20 ,/,, -i'_ - / -

10 ,,'-;

r I I I I I I I I I I ! I -

0

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

30 OCT 1991

3 MAR t993

SAMPLE: PRE-FLIGHT A = 0.539

(X40) POST-FLIGHT A = 0.619

CONTROL SAMPLE: E = 0.889

E = 0.895

F(LE# 1970_1

Figure 41. Polyethersulfone 4800-G (PES)--Reflectance vs. Wavelength

5_
Figure 42. TPXFilm--Left, flight sample; right, control sample

100 ,

m

90

8O

I I I I I I I I I I I

7O

u.I 60 " "-%

z S \1 I-.- 50

°

..J /

u_ 40 "

IT Ii V/

3o r/

20

m

10 f

m

0 i I I I

200 400 600 800

PRE-FLIGHT

POST-FLI( -_HT

SAMPLE: PRE-FLIGHT A = 0.489

(X42) POST-FLIGHT A = 0.540

t I

I I I I I I I I

1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.856

E = 0.873

30 OCT 1991

25 JAN 1993

FILE# 1970_1

Figure 43. TPX Film--Reflectance vs. Wavelength

56
Figure 44. 3M-PressureSensitiveTapeNo. 5--Left, flight sample;right, control sample

100

2O

10

0

2OO

m

PRE-FLIGHT

POST-FLI{ _HT

m

SAMPLE:

(X50)

m

I I I I I I I I I I I I

400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

PRE-FLIGHT A = 0.434 CONTROL SAMPLE: E = 0.735

POST-FLIGHT A = 0.523 E = 0.751

31 OCT 1991

27 JUL 1993

FILE# 1970 A

Figure 45. 3M-Pressure Sensitive Tape No. 5--Reflectance vs. Wavelength

57
Figure 46. Uralane 5750LV-A/B--Left, flight sample;right, control sample

100

90

80

I I I I I I I I I I I I

D i

7O

_j 60

O

Z

t-- 50 o _..._. /

u. 40

30 J

J /

10

0 I I I I I

-- PRE-FLIGHT

-- POST-FLIGHT

m

L/

m

I I I I I I I

200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.558 CONTROL SAMPLE: E = 0.843 al OCT1_1

(X66) POST-FLIGHT A = 0.648 E = 0.878 23JUL1993

FILE# 1970_B

Figure 47. Uralane 5750LV-A/B--Reflectance vs. Wavelength

58
Figure 48. Uralane 5753LV-A/B--Left, flight sample; right, control sample

100 I I I I I I I I I I I I

9O

8O

70

w 60

0

z

50

0

W

40

20

lO _

0 I I

200 400 600

SAMPLE: PRE-FLIGHT A = 0.612

(X67) POST-FLIGHT A = 0.651

FILE# 1970_B

i

PRE-FLIGHT

-- POST-FLIGHT m

y

I I I I I I I I I I

800 1000 1200 1400 1600 1800 2000 2200 2400 2600

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.880 31OCT1991

E = 0.912 23JUL1993

Figure 49. Uralane 5753LV-A/B--Reflectance vs. Wavelength

59
Figure 50. Epon 828/Versamid 140/TiO2--Left , flight sample; right, control sample

100

90

8O

70

LU 60

0

Z

I-- 50

0

LU

,,_1

u_ 40 Lu

rr

30

2O

10 _d'

m

0 I

2OO

SAMPLE:

(X68)

FILE# 1970_C

I | I I I I I ! I I I

\

PRE-FLIGHT

-- POST-FLIGHT

u

\

! ! I

400 600 800 1000

PRE-FLIGHT A = 0.212

POST-FLIGHT A = 0.289

I I I I I I

1200 1400 1600 1800 2000 2200

WAVELENGTH (nm)

CONTROL SAMPLE: E = 0.905

E = 0.898

m

I I

2400 2600

5NOV1_1

10MAYI_3

Figure 51. Epon 828/Versamid 140/TiO2--Reflectance vs. Wavelength

60
Figure 52. Aluminized Beta Cloth X389-7(Aluminized Exposed)--Left, flight sample; right,

control sample

100 i I i i i

90

80

70

m 60

o

z

<

I-- 50

o

LU

._J

u_ 40

w

rr

30

20

10

m

0

200

f

I I I I I I I

PRE-FLIGHT -

POST-FLIGHT m

i

I I I I I I I I I I

400 600 800 1000 1200 1400 1600 1800 2000 2200

WAVELENGTH (nm)

SAMPLE: PRE-FLIGHT A = 0.263 CONTROL SAMPLE: E = 0.125

(X69) POST-FLIGHT A = 0.266 E = 0.125

u

I I

2400 2600

6 NOV 1991

10 FEB 1993

FILE# 1970 D

Figure 53. Aluminized Beta Cloth X389-7(Aluminized Exposed)--Reflectance vs. Wavelength

61

Form Approved REPORT DOCUMENTATION PAGE ouBNo.o7o4-o188

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November 1996 Technical Memorandum

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

Atomic Oxygen and Space Environment Effects on Aerospace Materials

Flown with EOIM-III Experiment

6. AUTHOR(S)

John J. Scialdone, Carroll H. Clatterbuck, Mary Ayres-Treusdell,

Gloria Park, and Diane Kolos

! 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

Goddard Space Flight Center

Greenbelt, Maryland 20771

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

NASA Aeronautics and Space Administration

Washington, D.C. 20546-0001

Code 313

8. PERFORMING ORGANIZATION

REPORT NUMBER

96B00084

10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

TM- 104636

11. SUPPLEMENTARY NOTES

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Unclassified-Unlimited

Subject Category: 24

Report available from the NASA Center for AeroSpace Information,

800 Elkridge Landing Road, Lintbicum Heights, MD 21090; (301) 621-0390.

13. ABSTRACT (Maximum 200 words)

Polymer materials samples mounted on a passive carrier tray were flown aboard the STS-46 Atlantis shuttle as complement to the EOIM-III (Evaluation of Oxygen Interaction with Materials) experiment to evaluate the effects of atomic oxygen on

the materials and to measure the gaseous shuttle bay environment.

The morphological changes of the samples produced by the atomic oxygen fluence of 2.07E-20 atoms/cm 2 are being

reported. The changes have been verified using Electron Spectroscopy for Chemical Analysis (ESCA), gravimetric measurement, microscopic observations and thermo-optical measurements. The samples, including Kapton, Delrin, epoxies, Beta Cloth,

Chemglaze Z306, silver Teflon, silicone coatings, 3M tape and Uralane and Ultem, PEEK, Victrex (PES), Polyethersulfone and

Polymethylpentene thermoplastic, have been characterized by their oxygen reaction efficiency on the basis of their erosion

losses and the oxygen fluence. (See Table 1 for source name.) Those efficiencies have been compared to results from other

experiments, when available. The efficiencies of the samples are all in the range of E-24 g/atom. The results indicate that the

reaction efficiencies of the reported materials can be grouped in about three ranges of values. The least affected materials which

have efficiencies varying from 1 to 10 E-25 g/atom, include silicones, epoxies, Uralane and Teflon. A second group with

efficiency from 10 to 45 E-25 g/atom includes additional silicone coatings, the Chemglaze Z306 paint and Kapton. The third

range from 50 to 75 E-25 includes organic compound such as Pentene, Peek, Ultem, Sulfone and a 3M tape. A Delrin sample

had the highest reaction efficiency of 179 E-25 g/atom. Two samples, the aluminum Beta cloth X389-7 and the epoxy fiberglass

G- 11 nonflame retardant, showed a slight mass increase.

14. SUBJECT TERMS

Polymer materials, STS-46 Atlantis, ESCA, EOIM-III

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Unclassified

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6l

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