DEPARTMENT OF MECHANICAL ENGINEERING AND MECHANICS

SCHOOL OF ENGINEERING

OLD DOMINION UNIVERSITY

NORFOLK, VIRGINIA 23508

INVESTIGATION OF PARAMAGNETIC

RESPONSE OF METALLIC EPOXIES

By

Robert L. Ash, Principal Investigator

and

Hoshang Chegini, Research Assistant

Final Report

For the period June 1, 1985 to August 31, 1985

Prepared for the

National Aeronautics and Space Administration

Langley Research Center

Hampton, VA 23665

Under

Master Contract Agreement NAS-1-17993

Task Authorization No. 17

Dr. Jag J. Singh, Technical Monitor

Instrument Research Division

Submitted by the

Old Dominion University Research Foundation

P. 0. Box 6369

Norfolk, Virginia 23508

April 1986

{NASA-CR-176551) INVE51IGA1IC8 OF H86-24761

PABAMAGNETIC fi£S£CNSE 01 METALLIC EPOXJES

Final Report, 1 Jun. - 31 Aug . 1985 (Old

Dominion Univ.) 13 p BC AQ2/KJ A01 CSC1 11D Dnclas

G3/24 43378
INVESTIGATION OF PARAMAGNETIC

RESPONSE OF METALLIC EPOXIES

By

Robert L. Ash1 and Hoshang Chegini2

SUMMARY

The paramagnetic properties of epoxies which were impregnated with

metal ions were examined as the primary task in this research. A major

conclusion of this work was that the quality control of the epoxies was

insufficient to permit reliable evaluation. Subsequently, a new set of

specimens are being prepared.

As an additional task, the research assistant has investigated a new

method for estimating heats of combustion for saturated hydrocarbons. The

results of that investigation have shown that the empirical approach developed by Singh and Sprinkle is a promising method for on-line measurements.

Chairman/Eminent Professor, Department of Mechanical Engineering, Old Dominion University, Norfolk, Virginia 23508. 2Research Assistant, Department of Mechanical Engineering, Old Dominion

University, Norfolk, Virginia 23508.
I. ELECTRON PARAMAGNETIC RESPONSE CHARACTERIZATION

OF METAL CONTAINING EPOXIES

Several types of epoxies are currently being used for aerospace application because of their versatility, processability, chemical resistance,

low density, and low cost. Since pure polymers do not meet all the requirements needed for aerospace applications, research efforts have been directed

toward the modification of these materials (Ref. 1).

One of these modifications is the incorporation of metal ions into

these resin systems. Important changes can occur in the properties of these

polymeric materials when small quantities of metallic ions are introduced

into the systems. Such changes as increases in mechanical strength and

increase in moisture resistance are reported in Refs. 2-6, although the

reasons for these changes are not fully understood. In order to obtain more

information on the electronic structure and the coordination of the metal

ions in these polymer matrices, the magnetic properties of the systems have

been investigated. Studies were performed for MY-720* epoxy matrices containing Fe, Ni, Co, and Cr metal ions in various concentration ratios.

A set of sixteen Me (acac) ** modified epoxy specimens were sent to

/\

Virginia Polytechnic Institute for magnetic susceptibility measurements.

The magnetic susceptibility can be calculated from the expression (Ref. 7):

W

where w is net change of sample mass in the magnetic field and W is the

mass of the sample out of field. Analysis of standard material allows determination of 6 values for any particular magnetic field strength. The

*MY-720 epoxy resin is a product of Narmco Materials, Inc.

**Me (acac)x is modified epoxy specimen where Me represents the metal ion

in acetylacetonates (acac).
analysis of data did not provide us with an acceptable solid conclusion. As

a result repeated measurement became necessary. Two sets of identical specimens were sent to Virginia Commonwealth University and Virginia Tech.

Unfortunately the analysis of the new sets of data suggested nonuniformality

of metal ion distribution in the specimens. Progress in this work has been

stopped until a new set of specimens are fabricated.

II. A NEW METHOD TO DETERMINE HEATS OF COMBUSTION OF GASEOUS

HYDROCARBONS (Ref. 8)

The heat of combustion of hydrocarbons are presently determined

(Ref. 9) by using a constant volume bomb calorimeter. These measurements

can be very accurate (<1%). However, calorimetric measurements cannot be

used on-line, and require information about the thermal properties of the

combustion products of the test sample. The method reported here is direct,

on-line, and does not require any prior knowledge of the exact composition

of test sample. Since the heat of combustion of the test gas depends on its

effective hydrocarbon content, measurement of the amount of oxygen needed

for complete combustion can provide us with thermal content of the test gas.

NASA has recently developed an oxygen-monitoring-and-control system for the

Langley 8-foot high temperature tunnel (Ref. 10). It is based on Y2_03_

stabilized Zr02 electrochemical sensor. The system is capable of maintaining oxygen concentration in the combustion product gases at 20.9 ± 1.0

percent.

The essential chemistry of the hydrocarbon combustion process in oxygen-enriched air is represented by the following equation:
£(A1r) + m(02) + n(C¥Hj -»• *(A1r) + nx(C02) + - y (H20)

x y 2

Input channel _ Output channel

m - n (4x + y Ft )| (02) + Heat (I)

where C H represents the hydrocarbon in the reaction. The hydrocarbon

x y

flowrate can be controlled and measured by thermal mass flowmeters (Ref.

11). This equation assumes that the added oxygen in the input channel was

equal to the amount needed for complete combustion of the hydrocarbon. The

mole fraction of oxygen in the output channel of equation (1) is given by

the following equation:

P(0)2 =

0.2095 i + I'm - n (4x * y.\|

L

 J

- n4x

If the mole fraction of oxygen in the output channel is the same as in the

reference gas (air), then

0.2095 £ + fm - n ( 4x + yVl

L V 4 )\ 0.2095 = 1= 1 I—7

-! (3)

Simplifying equation (3) yields

_

n 4(1 - 0.2095)
calculated values of m/n for some of the pure saturated hydrocarbons in

standard and nonstandard air are summarized in Table 1.

Table 1. Summary of m/n-Values for Selected Saturated Hydrocarbons for

P(02) = 0.2042 and 0.2095.

Hydrocarbon

Methane

Ethane

Propane

Butane

Pentane

Chemical

Formula

«4

-

C2H6

C

3

H

8

C

4

B

10

C

5

H

12

m/n - Value

P(02).

0.2042

2.770

4.783

6.796

8.809

10.823

P(02)-

0.2095

2.795

4.825

6.855

8.855

10.915

Hydrocarbon

Hexane

Heptane

Octane

Nonane

Decane

Chemical

Formula

C

6

H

14

C

7

H

16

C

8

H

18

C

9

H

20

C

10H22

m/n - Value

P(02) -

0.2042

12.836

14.849

16.862

18.875

20.888

P(02) -

0.2095

12.945

14.975

17.005

19.035

21.065

If the test gas is not a pure single hydrocarbon, but is a mixture of two or

more hydrocarbons, equation (4) can be used directly to calculate m/n values

for the effective test hydrocarbon where the X and Y values for the

mixture can be obtained from:

x

 •

Y =

v,

(5)

Here, f represents the mole fraction of each hydrocarbon in the test

i

gas. For example, for a test gas containing equal mole fractions of

and €2^, the equivalent hydrocarbon would be Ci
Because m/n-values for various test gases containing saturated hydrocarbons are related to their chemical composition, they can serve as the

basis for direct determination of their heats of combustion. Table 2

summarizes the heat of combustion of several pure saturated hydrocarbons.

Table 2. Summary of Heats of Combustion of Selected Saturated Hydrocarbons

Hydrocarbon

CH,

rC H2

H6

C3H8

C4H10

C5H12

C&H14

m/n

P(02) - 0.2095

2.795

4.825

6.855

8.885

10.915

12.945

Heat of Combustion

KCal/Mode

212.80

372.82

530.61

687.65

845.10

1002.55

Heat of Combustion

m/n

76.14

77.27

77.40

77.39

77.43

77.45

III. EXPERIMENTAL VERIFICATION OF THEORETICAL PROCEDURE

The experimental plan involved measuring m/n values for the following

kinds of test gas samples:

1. Pure, saturated gaseous hydrocarbons (methane, ethane, propane, and

butane, etc.)

2. Binary mixtures of selected saturated hydrocarbons (i.e., no noncombustible components)

3. Binary mixtures containing a saturated hydrocarbon and an inert

gas.

4. Gaseous mixtures containing several saturated hydrocarbons and

selected noncombustible impurities.

It should be noted that n in the parameter m/n represents the vol-
une flow rate of the test gas. We have used a positive displacement dry

test meter for measuring the volumetric flowrate (n) of the test gases.

Results of heat of combustion are summarized in Tables 3, 4, and 5 for

various test gases.

Table 3. Summary of Experimental and Theoretical m/n-Values for Selected

Hydrocarbons in Air [P(02) = 20.42%].

• Test

Hydrocarbon

C«4

C2H6

C3H8

C

4

H

10

. " Hydrocarbon

Flowrate

(n) , Seen

71.80+0.72

45.85+0.46

29.18+0.30

24.20+0.24

Equalizing Oxygen

Flowrate

(ra) , Seem

200.80+1.00

214.67+1.00

199.71+1.00

213.00+1.00

Carrier Air

Flovrate

(17, Seem

500.0

500.0

500.0

500.0

tn/n-Value

Experimental

2.797+0.042

4.682+0.070

6.843+0.103

8-.801+0.132

Theoretical

2.770

4.78.1

6.796

8.309

From the data summarized in Tables 3 and 4, it is apparent that the calculated and the experimental values of m/n for various types of mixtures are

in reasonably good agreement. As has been indicated earlier, the m/n-values

for the mixtures can be used to infer their heats of combustion. Using the

reported heat of combustion values for saturated hydrocarbons listed in

Table 2, the following relationship has been derived between m/n and the

heat of combustion values expressed in kilocalories per mole (Ref. 11).

Based on a fourth order least square fit the following equation was

obtained.

Heat of combustion [Kcal/mole] = aQ + ai (m/n) + 82 (m/n)2 33 (m/n)

(6)
where a = -23.2134

o

aj = +91.2088

a2 = -2.9745

a3 = +0.3032

a, = -0.0117

A comparison between the heat of combustion values calculated on the basis

of their experimentally observed m/n-values and known chemical composition

is given in Tables 3, 4, and 5. It is apparent that they are in reasonably

good agreement.
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Table 5. Comparison Between the Calculated and Measured Values of Heats

of Combustion for Various Gas Mixtures.

Mixture

Composition

Heat of Combustion, KCal/Mole

Experimental Calculated

0.5 CHA +0. 5 C2Hg

0.5 CHA + 0.5 C3Hg

0.5 CHA -I- 0.5 CAH1Q

0.5 0.5

0.5 CHA +0. 5 C02

0.5

0.5

0.5

0.5

0.5 N2

0.5 C02

0.5 N2

0.5 C0

292.6+3.A

369.5+5.2

446.3+7.A

110.6+2.2

110.4+2.2

193.0+3.1

193.4+2.6

274.3+3.8

274.7+3.0

292.2+3.9

371.1+5.2

449.2+2.2

109.0+2.8

109.4+2.6

192.2+2.2

192.0+1.8

273.3+1.6

273.0+1.4

C2H6(44.632) + C3Hg(25.88Z)

CAH10(10.81%) + C02(5.09%)

M2(13.59%)

CHA(53.04%) + C2H6 (26.09%)

C3Hg (lS.42%) + C02(1.43%) +

C2H6(17.12X)

C02 (3.34%)

CHA (50.84%)

C3Hg (24.87%)

N2(3.83S)

CHA(51.51Z) + C2H6 (21.24%)

C3H8 (23.82%) + C02 (1.74%)

K0 (1.691)

390.1+11.7

307.7+7.8

297.4+5.6

311.5+8.0

380.6+9.9

308.3+8.0

305.4+8.0

315.9+8.3

10
REFERENCES

1. Crozier, D.; Morse, 6.; and Tajima, Y.: "The Development of Improved

Chemical Analysis Methods for Epoxy Resins," SAMPLE Journal, Sep./Oct.

(1982).

2. Taylor, L. T.; Carver, V. C.; Furtsch, T. A.; and St. Clair, A. K.:

"Incorporation of Metal Ions in Polyimides," ACS Symposium Series, No.

121, Modification of Polymers, (1980).

3. Taylor, Larry T.; St. Clair, Anne K.; Carver, Vickie C.; Furtsch,

Thomas A.: U.S. Patent 4,311,615, Jan. 1982.

4. St. Clair, Anne K.; Taylor, Larry T.; St. Clair, Terry L.: U.S. Patent

4,284,461, Aug. 18, 1981.

5. Cizmecioglu, M.; Hong, S. D.; Moacanin, 0.; and Gupta, A.: "Spectroscopic Characterization of Narmco 5208 Epoxy Neat-Resin Formulations,"

Polymer Preprints, 224-225, (1981).

6. Smith, J. 0. B.: "Metal Acetylacetonates as Latent Accelerators for

An-hydride-Curec Epoxy Resins," J. Appl. Polym. Sci., 26, 979-986

(1981).

7. Loeb, L. B.: "Fundamentals of Electricity and Magnetism," Dover Publications, Inc., New York.

8. Singh, J. J.; Sprinkle, D. R.; and Puster, R. L.: "New Method for Determining Heats of Combustion of Gaseous Hydrocarbons," NASA TP 2531,

1985.

9. Sunner, S.; Mansson, M.: "Experimental Chemical Thermodynamics,"

Pergamon Press, Vol. 1, 1979.

10. Singh, J. J.; Davis, W. T.; and Puster, R. L.: "Proposed Fast-Response

Oxygen Monitoring and Control System for the Langley 8-Foot High

Temperature Tunnel," NASA TP 2218, 1983.

11. Singh, J. J. and Sprinkle, D. R.: "A New Technique for Measuring Gas

Conversion Factors for Hydrocarbon Mass Flowmeters," NASA TM-815676,

1983.

11
DEPARTMENT OF MECHANICAL ENGINEERING AND MECHANICS

SCHOOL OF ENGINEERING

OLD DOMINION UNIVERSITY

NORFOLK, VIRGINIA 23508

INVESTIGATION OF PARAMAGNETIC

RESPONSE OF METALLIC EPOXIES

By

Robert L. Ash, Principal Investigator

and

Hoshang Chegini, Research Assistant

Final Report

For the period June 1, 1985 to August 31, 1985

Prepared for the

National Aeronautics and Space Administration

Langley Research Center

Hampton, VA 23665

Under

Master Contract Agreement NAS-1-17993

Task Authorization No. 17

Dr. Jag J. Singh, Technical Monitor

Instrument Research Division

Submitted by the

Old Dominion University Research Foundation

P. 0. Box 6369

Norfolk, Virginia 23508

April 1986
INVESTIGATION OF PARAMAGNETIC

RESPONSE OF METALLIC EPOXIES

By

Robert L. Ash1 and Hoshang Chegini2

SUMMARY

The paramagnetic properties of epoxies which were impregnated with

metal ions were examined as the primary task in this research. A major

conclusion of this work was that the quality control of the epoxies was

insufficient to permit reliable evaluation. Subsequently, a new set of

specimens are being prepared.

As an additional task, the research assistant has investigated a new

method for estimating heats of combustion for saturated hydrocarbons. The

results of that investigation have shown that the empirical approach developed by Singh and Sprinkle is a promising method for on-line measurements.

Chairman/Eminent Professor, Department of Mechanical Engineering, Old Dominion University, Norfolk, Virginia 23508. 2Research Assistant, Department of Mechanical Engineering, Old Dominion

University, Norfolk, Virginia 23508.
I. ELECTRON PARAMAGNETIC RESPONSE CHARACTERIZATION

OF METAL CONTAINING EPOXIES

Several types of epoxies are currently being used for aerospace application because of their versatility, processability, chemical resistance,

low density, and low cost. Since pure polymers do not meet all the requirements needed for aerospace applications, research efforts have been directed

toward the modification of these materials (Ref. 1).

One of these modifications is the incorporation of metal ions into

these resin systems. Important changes can occur in the properties of these

polymeric materials when small quantities of metallic ions are introduced

into the systems. Such changes as increases in mechanical strength and

increase in moisture resistance are reported in Refs. 2-6, although the

reasons for these changes are not fully understood. In order to obtain more

information on the electronic structure and the coordination of the metal

ions in these polymer matrices, the magnetic properties of the systems have

been investigated. Studies were performed for MY-720* epoxy matrices containing Fe, Ni, Co, and Cr metal ions in various concentration ratios.

A set of sixteen Me (acac) ** modified epoxy specimens were sent to

Virginia Polytechnic Institute for magnetic susceptibility measurements.

The magnetic susceptibility can be calculated from the expression (Ref. 7):

w

where w is net change of sample mass in the magnetic field and W is the

mass of the sample out of field. Analysis of standard material allows determination of 6 values for any particular magnetic field strength. The

*MY-720 epoxy resin is a product of Narmco Materials, Inc.

**Me (acac)x is modified epoxy specimen where Me represents the metal ion

in acetylacetonates (acac).
analysis of data did not provide us with an acceptable solid conclusion. As

a result repeated measurement became necessary. Two sets of identical specimens were sent to Virginia Commonwealth University and Virginia Tech.

Unfortunately the analysis of the new sets of data suggested nonuniformality

of metal ion distribution in the specimens. Progress in this work has been

stopped until a new set of specimens are fabricated.

II. A NEW METHOD TO DETERMINE HEATS OF COMBUSTION OF GASEOUS

HYDROCARBONS (Ref. 8)

The heat of combustion of hydrocarbons are presently determined

(Ref. 9) by using a constant volume bomb calorimeter. These measurements

can be very accurate (<1%). However, calorimetric measurements cannot be

used on-line, and require information about the thermal properties of the

combustion products of the test sample. The method reported here is direct,

on-line, and does not require any prior knowledge of the exact composition

of test sample. Since the heat of combustion of the test gas depends on its

effective hydrocarbon content, measurement of the amount of oxygen needed

for complete combustion can provide us with thermal content of the test gas.

NASA has recently developed an oxygen-monitoring-and-control system for the

Langley 8-foot high temperature tunnel (Ref. 10). It is based on Y2_03_

stabilized Zr02 electrochemical sensor. The system is capable of maintaining oxygen concentration in the combustion product gases at 20.9 ± 1.0

percent.

The essential chemistry of the hydrocarbon combustion process in oxygen-enriched air is represented by the following equation:
£(Air) + m(02) + n(C¥Hj -»• £(A1r) + nx(C02) +-Y (H20)

A y 2

Input channel _ _ Output channel

L - n (4x + y\"\ (02) + Heat (1)

where C H represents the hydrocarbon in the reaction. The hydrocarbon

x y

flowrate can be controlled and measured by thermal mass flowmeters (Ref.

11). This equation assumes that the added oxygen in the input channel was

equal to the amount needed for complete combustion of the hydrocarbon. The

mole fraction of oxygen in the output channel of equation (1) is given by

the following equation:

0.2095 £ + Fm - n (**

 +

P(0)2 =

If the mole fraction of oxygen in the output channel is the same as in the

reference gas (air), then

0.2095

0.2095 = - L - ' - ^_XJ (3)

—M—

Simplifying equation (3) yields

m= 4x + 1.2095y ,„

n 4(1 - 0.2095)
calculated values of m/n for some of the pure saturated hydrocarbons in

standard and nonstandard air are summarized in Table 1.

Table 1. Summary of m/n-Values for Selected Saturated Hydrocarbons for

P(02) = 0.2042 and 0.2095.

Hydrocarbon

Methane

Ethane

Propane

Butane

Pentane

Chemical

Formula

CH,

C

2

H

6

C

3

H

8

C

4

H

10

C

5

H

12

m/n - Value

P(02).

0.2042

2.770

4.783

6.796

8.809

10.823

P(02)-

0.2095

2.795

4.825

6.855

8.855

10.915

Hydrocarbon

Hexane

Heptane

Octane

Nonane

Oecane

Chemical

Formula

C

6

H

14

C7H16

C

8

H

18

C

9

H

20

C

10H22

m/n - Value

P(02) -

0.2042

12.836

14.849

16.862

18.875

20.888

P(02) -

0.2095

12.945

14.975

17.005

19.035

21.065

If the test gas is not a pure single hydrocarbon, but is a mixture of two or

more hydrocarbons, equation (4) can be used directly to calculate m/n values

for the effective test hydrocarbon where the X and Y values for the

mixture can be obtained from:

X = f .X.

(5)

Y = J f. Y

Here, f represents the mole fraction of each hydrocarbon in the test

i

gas. For example, for a test gas containing equal mole fractions of CH^

and (^HS, the equivalent hydrocarbon would be Ci
Because m/n-values for various test gases containing saturated hydrocarbons are related to their chemical composition, they can serve as the

basis for direct determination of their heats of combustion. Table 2

summarizes the heat of combustion of several pure saturated hydrocarbons.

Table 2. Summary of Heats of Combustion of Selected Saturated Hydrocarbons

Hydrocarbon

CH4

C

2

H

6

C3H8

C4H10

C5H12

C6H14

*

m/n

P(02) - 0.2095

2.795

4.825

6.855

8.885

10.915

12.945

Heat of Combustion

KCal/Mode

212.80

372.82

530.61

687.65

845.10

• 1002.55

Heat of Combustion

m/n

76.14

•77.27

77.40

77.39

77.43

77.45

III. EXPERIMENTAL VERIFICATION OF THEORETICAL PROCEDURE

The experimental plan involved measuring m/n values for the following

kinds of test gas samples:

1. Pure, saturated gaseous hydrocarbons (methane, ethane, propane, and

butane, etc.)

2. Binary mixtures of selected saturated hydrocarbons (i.e., no noncombustible components)

3. Binary mixtures containing a saturated hydrocarbon and an inert

gas.

4. Gaseous mixtures containing several saturated hydrocarbons and

selected noncombustible impurities.

It should be noted that n in the parameter m/n represents the vol-
ume flow rate of the test gas. We have used a positive displacement dry

test meter for measuring the volumetric flowrate (n) of the test gases.

Results of heat of combustion are summarized in Tables 3, 4, and 5 for

various test gases.

Table 3. Summary of Experimental and Theoretical m/n-Values for Selected

Hydrocarbons in Air [P(02) = 20.42%].

• Test

Hydrocarbon

<*4

C

2

H

6

C

3

H

8

C

4

H

10

Hydrocarbon

Flovrate

(n) , Seen

71.80+0.72

45.85+0.46

29.18+0.30

24.20+0.24

Equalizing Oxygen

Flowrace

(ta) , Seem

200.80+1.00

214.67+1.00

199.71+1.00

213.00+1.00

Carrier Air

Flowrace

(17, Seem

500.0

500.0

500.0

500.0

m/n-Value

Experimental

2.797+0.042

4.682+0.070

6.843+0.103

8.801+0.132

Theoretical

2.770

4.781

6.796

8.809

From the data summarized in Tables 3 and 4, it is apparent that the calculated and the experimental values of m/n for various types of mixtures are

in reasonably good agreement. As has been indicated earlier, the m/n-values

for the mixtures can be used to infer their heats of combustion. Using the

reported heat of combustion values for saturated hydrocarbons listed in

Table 2, the following relationship has been derived between m/n and the

heat of combustion values expressed in kilocalories per mole (Ref. 11).

Based on a fourth order least square fit the following equation was

obtained.

Heat of combustion [Kcal/mole] = a^ + ai (m/n) + 32(m/n)2 a3(m/n)

(6)
where a = -23.2134

o

3j = +91.2088

a2 = -2.9745

a3 = +0.3032

a,, = -0.0117

A comparison between the heat of combustion values calculated on the basis

of their experimentally observed m/n-values and known chemical composition

is given in Tables 3, 4, and 5. It is apparent that they are in reasonably

good agreement.
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of Combustion for Various Gas Mixtures.

Mixture

Composition

Heat of Combustion, KCal/Mole

Experimental Calculated

0.5 CHA + 0.5

0.5 CHA + 0.5

0.5 CH + 0.5

0.5 CH^ + 0.5 N2

0.5 CH^ + 0.5 C02

0.5

0.5

0.5

0.5

0.5 N2

0.5 C02

0.5 N2

0.5 C02

292.6+3.A

369.5+5.2

446.3+7.4

110.6+2.2

110.4+2.2

193.0+3.1

193.4+2.6

274.3+3.8

274.7+3.0

292.2+3.9

371.1+5.2

449.2+2.2

109.0+2.8

109.4+2.6

192.2+2.2

192.0+1.8

273.3+1.6

273.0+1.4

C2H6(44.63X) + C3Hg(25.88%)

) + C02(5.09%) 390.1+11.7

M2(13.59%)

C2H6(26.09%) -t

C3Hg(lS.42%) + C02(1.43%) + 307.7+7.8

CH/((50.84%) + C2H6(17.12%)

C Hg(24.87Z) + C02(3.34%) 297.4+5.6

N2(3.83%)

C3Hg(23.82%) 311.5+8.0

380.6+9.9

308.3+8.0

305.4+8.0

315.9+8.3

10
REFERENCES

1. Crozier, D.; Morse, 6.; and Tajima, Y.: "The Development of Improved

Chemical Analysis Methods for Epoxy Resins," SAMPLE Journal, Sep./Oct.

(1982).

2. Taylor, L. T.; Carver, V. C.; Furtsch, T. A.; and St. Clair, A. K.:

"Incorporation of Metal Ions in Polyimides," ACS Symposium Series, No.

121, Modification of Polymers, (1980).

3. Taylor, Larry T.; St. Clair, Anne K.; Carver, Vickie C.; Furtsch,

Thomas A.: U.S. Patent 4,311,615, Jan. 1982.

4. St. Clair, Anne K.; Taylor, Larry T.; St. Clair, Terry L.: U.S. Patent

4,284,461, Aug. 18, 1981.

5. Cizmecioglu, M.; Hong, S. D.; Moacanin, J.; and Gupta, A.: "Spectroscopic Characterization of Narmco 5208 Epoxy Neat-Resin Formulations,"

Polymer Preprints, 224-225, (1981).

6. Smith, J. 0. B.: "Metal Acetylacetonates as Latent Accelerators for

An-hydride-Curec Epoxy Resins," J. Appl. Polym. Sci., 26, 979-986

(1981). ~

7. Loeb, L. B.: "Fundamentals of Electricity and Magnetism," Dover Publications, Inc., New York.

8. Singh, J. J.; Sprinkle, D. R.; and Puster, R. L.: "New Method for Determining Heats of Combustion of Gaseous Hydrocarbons," NASA TP 2531,

1985.

9. Sunner, S.; Mansson, M.: "Experimental Chemical Thermodynamics,"

Pergamon Press, Vol. 1, 1979.

10. Singh, J. J.; Davis, W. T.; and Puster, R. L.: "Proposed Fast-Response

Oxygen Monitoring and Control System for the Langley 8-Foot High

Temperature Tunnel," NASA TP 2218, 1983.

11. Singh, J. J. and Sprinkle, D. R.: "A New Technique for Measuring Gas

Conversion Factors for Hydrocarbon Mass Flowmeters," NASA TM-815676,

1983.

11
INVESTIGATION OF PARAMAGNETIC

RESPONSE OF METALLIC EPOXIES

By

Robert L. Ash1 and Hoshang Chegini2

The paramagnetic properties of epoxies which were impregnated with

metal ions were examined as the primary task in this research. A major

conclusion .of this work was that the quality control of the epoxies was

insufficient to permit reliable evaluation. Subsequently, a new set of

specimens a»e being prepared.

^r- As an additional task,'the research assistant has investigated a new

method for estimating "heats of combustion for saturated hydrocarbons. The

results of that investigation have shown that the empirical approach developed by Singh and Sprinkle is a promising method for on-line measurements.

Chairman/Eminent Professor, Department of Mechanical Engineering, Old Dominion University, Norfolk, Virginia 23508. 2Research Assistant, Department of Mechanical Engineering, Old Dominion

University, Norfolk, Virginia 23508.