# Status Report on the Development of HFC®245fa as a Blowing Agent

M. C. BOGDAN
, D. J. WILLIAMS
, P. B. LOGSDON
, R. C. PARKER AlliedSignal Inc.

ABSTRACT December 31,1995 marked the end to the manufacture of CFCs in the U.S. for use as blowing agents. The foam industry has successfully converted to HCFC-141b andother blowing agents. This, however, is not the last transition that the industry needs to make. HCFCs have specific phaseout dates, according to theMontreal Protocol which differ across the globe. Currently, the manufacture of HCFC-141b for use as a blowing agent in the U.S., will cease on January 1, 2003. The identification of the next generation of blowing agents has begun as a response to this market need. AlliedSignal is committed to supplying a blowing agent to meet customer needs in the foam industry. In 1994, atthe Polyurethane World Congress, AlliedSignal announced HFC-245fa (1,1,1,3,3- pentafluoropropane) as their "third generation" blowing agent candidate to replace HCFC-141b. HFC-245fa was selected on the basis of the optimum combination of possessed attributes; it is a liquid, nonflammable blowing agent with acceptable environmental characteristics and good toxicological properties. Testing performed to date on foams prepared with HFC-245fa have demonstrated improved physical properties and k-factor aging versus those made withHCFC-141b. This paper discusses the recent work conducted by AlliedSignal in continuing the development of HFC-245fa . Before 1996, AlliedSignal's major research efforts have been in defining the properties of HFC-245fa and provingit as a feasible blowing agent. We are sensitive to the complexities of developing new foam technologies and want to minimize any transition difficulties through customer partnering. Because of this our focus has now shifted todeveloping a database of information to assist our customers in selecting and converting to HFC-245fa. This paper contains a discussion of the latest toxicity and environmental data. It will focus on answering somecommonly asked customer questions in the areas of polyol solubility, premix vapor pressures, and cell gas content. Research work is currently underway to optimize the use of HFC-245fa in various industry applications which focuses on improving k-factor and physical properties. This work, along with a comparison of Total Equivalent Warming Impact (TEWI) of various blowing agents being considered, is also included. 

### INTRODUCTION 

# The production of HCFC-141b is currently scheduled to cease as of January 1, 2003. In order to meet future energy and environmental requirements, alternative blowing agents to HCFCs, currently used in insulating foam applications, will be required.Although there are several potential options for replacement blowing agents, many applications will continue to require .a liquid , non-flammable blowing agent designedto produce foams with low thermal conductivity using traditional processing techniques. The most promising classof materials to fill this need are the liquid HFCs. AlliedSignal is committed to supplying an alternative HFC blowing agent to meet these needs.In 1994 at the Polyurethane World Congress, AlliedSignal announced that HFC-245fa (1,1,1,3,3- pentafluoropropane) is our primary blowing agent candidate to replace HCFC-141b. We consider HFC-245fa to be the optimum replacement candidate for HCFC-141b since it has similar physical properties , is non-flammable , is acceptable environmentally and toxicologically and canmeet the performance requirements of the foam insulation market. With the transition from HCFC-141b on the horizon, there is much work to begin for an effective transition. Each foam market segment has its own set of testing andtrials which must be completed before products containing a new blowing agent can be commercially sold. Theextent and time requirements vary dramatically from segment to segment. In addition, there are several phases of toxicity testing which must be completed and government approvals which must be obtained prior to HFC-245fa becoming a commercial product. AlliedSignal has presented a continuing series of papers since 1992, updating the industry on our liquid HFC blowing agent development program. This paper provides the most recent information on the physical properties and toxicology of HFC-245fa. With the stronger push to utilize energy efficient appliances, reduce energy utilization in current structures and as well as pressure to create new structures which are more "environmentally friendly", we have included a discussion and application ofTotal Equivalent Warming Impact or TEWI on refrigerator trials performed to date. Finally, we have included information relating to the manufacture of foam with

POLYURETHANES EXPO '96 

# Status Report on the Deve.lopment of HFC-245fa as a Blowing Agent

M. C. BOGDAN, D. 

## J. WILLIAMS, P. B. LOGSDON, R. C. PARKER

AlliedSignalInc.



### ABSTRACT

December 31,1995 marked the end tothe manufacture ofCFCs in the U.S. for use as blowing agents. The foam industry has successfully converted to HCFC-141b and other blowing agents. This, however, is not the last transition that the industry needs to make.

HCFCs have specific phaseout dates, according to the Montreal Protocol which differ across the globe. Currently, the manufacture ofHCFC-141b for use as a blowing agent in the U.S., will cease on January 1, 2003. The identification ofthenextgeneration ofblowing agentshas begun as a response to this market need.

AlliedSignal is committed to supplying a blowing agent to meet customer needs in the foam industry. In 1994, at the Polyurethane World Congress, AlliedSignal announced HFC-245fa (1,1,1,3,3- pentafluoropropane) as their "third generation" blowing agent candidate to replace HCFC-141b. HFC-245fa was selected on the basis ofthe optimum combination ofpossessed attributes; it is
a liquid, nonflammable blowing agent with acceptable environmental characteristics and good toxicological properties. Testing performed to date on foams prepared with HFC-245fa have demonstrated improved physical properties and k-factor aging versus those made with HCFC-141b. This paper discusses the recent work conducted by AlliedSignal in continuing the development of HFC-245fa.

Before 1996, AlliedSignal's major research efforts have been in defining the properties ofHFC-245fa and proving it as a feasible blowing agent. We are sensitive to the complexities ofdeveloping new foam technologies and wantto minimize any transition difficulties through customer partnering. Because ofthis our focus has now shifted to developing a database of information to assist our customers in selecting and converting to HFC-245fa.

This paper contains a discussion of the latest toxicity and environmental data. It will focus on answering some commonly asked customer questions in the areas ofpoly

### 01 solubility, premixvaporpressures, and cell gas content.

Research work is currently underway to optimize the
use ofHFC-245fa in various industry applications which focuses on improving k-factor and physical properties. This 

### work, along with a comparison ofTotal Equivalent Warming Impact (TEWI) ofvarious blowing agents being considered, is also included. 

### INTRODUCTION 

# The production ofHCFC-141b is currently scheduled to
cease as ofJanuary 1, 2003. In order to meet future energy and environmental requirements, alternative blowing agents to HCFCs, currently used in insulating foam applications, will 

### &e required.

Althoughthere are severalpotential optionsfor replacement blowing agents, many applications will continue to require.a liquid
, non-flammable blowing agent designed to produce foams withlow thermal conductivityusingtraditional processing techniques. The most promising class ofmaterials to fill this need are the liquid HFCs. AlliedSignal is committed to supplying an alternative HFC blowing agent to meet these needs.

In 1994 at the Polyurethane World Congress, AlliedSignal announced that HFC-245fa (1,1,1,3,3- pentafluoropropane) is our primary blowing agent candidate to replace HCFC-141b. We consider HFC-245fa to be the optimum replacement candidate for HCFC-141b since it has similar physical properties, is non-flammable
, is acceptable environmentally and toxicologically and can meet the performance requirements of the foam insulation market.

With the transition from HCFC-141b on the horizon, there is much work to begin for an effective transition. Each foam market segmenthas its own setoftesting and trials which must be completed before products containing a new blowing agent can be commercially sold. The extentandtimerequirementsvarydramaticallyfrom segment to segment. In addition, there are several phases of toxicity testingwhich mustbe completed and government approvals which must be obtained prior to HFC-245fa becoming a commercial product.

AlliedSignal has presented a continuing series of papers since 1992, updating the industry on our liquid HFC blowing agent development program. This paper provides the most recent information on the physical properties and toxicology ofHFC-245fa.With the stronger push to utilize energy efficient appliances, reduce energy utilizationincurrentstructures and aswell aspressureto create new structures which are more "environmentally friendly", wehaveincludeda discussion andapplicationof Total Equivalent WarmingImpact or TEW! on refrigerator trials performed to date. Finally, we have included information relating to the manufacture of foam with

POLYURETHANES Expo '96 

### 1Table 1

. Blowing agentphysical properties

50 Molecular Weight 134.0 137.4 116.9 70.0 72.0 Boiling point °F 59.5 74.8 89.7 120.7 96.8 Liquid density, g/cc @68°F 1.32 1.49 124 0.75 0.63 Vapor Pressure, psia @68°F 17.8 12.8 10.0 4.9 8.3 Vapor Thermal Conductivity, BTU in/hrlt°oF @ 111°F 0.097 0. 064 0.084 BTU in/hr ftl°F @ 77°F 0.061 0.072 0.083 0.104 Flame Limits. volume % None' None' 7.6 - 17.7° 1.4 - 9.4° 1.3 - 8.' Flash Point. °F None None None -35 -40

' ASTM E681 , amfaen• 10008068 maidf ,gfNan aye„ ` Tes method not ap°0Md Table 2. Blowing agent flammability properties

HFC-245fa CFC-11 HCFC-141b Cyclopentane n-Pentane Flash Point, F Tag Closed Cup None None None -35' -40' (ASTM D56.67) Setaflash Closed Tester (ASTM 03828.67) None None None
Tag Open Cup (ASTM 0310.86) None None - None Vapor Flame Limits, Vol % None None 7.6-17.7° 1.4-9.4' 1 -3-8.0' (ASTM E661-85) Minimum Ignition Energy , m) N/A N/A 18,000 0.2-0.3 Heat of Combustion , kcat/mol 244 220 786 839 Test method not Spectiled ° Amb,ent condi9ons
, match ignm«,

Table 3. Blowing agent environmental properties

HFC-245fa CFC

-11 HCFC

-141b HFC-134a C ntane n-Pentane Ozone Depletion Potential 0 1 ' 0.11 0 0 0 Atmospheric Lifetime , years 8.4 50 9,4 14 Few Da Global Warming P^entia 100 yr time h000iO1 (CO, . tl 820 4000 630 1300 3 3 VOC Status No No No No Yes Yes A9 Osfa wept HFC-245i, MW from 'Eneegy and Dlopol Wamvrp Its of lon.otKey iw Next GO{eratan CFCend HCFC NmmaSvm 1994 ° Ndi wmiy b be mrttgerad a VOC

d3' HFC-245ta CFC-11 HCFC- 141b Cyclopentane n-Pentane

60 iW

T eiPeel 9ra, 'F -FHFC.2451, -e--HCFC- laud --f-CFC. 11 - M- C,cb°ema°e 110 1zd

Figure 1 . Vapor pressures of some foam blowing agents 12C

HFC-245fa: Solubility, vapor pressure, a discussion of the effect of surfactants on foam properties, cell gas content, foam aging and k-factor vs. mean temperature. The paperconcludes with a discussion ofAlliedSignal's plans for continuing development and commercialization of HFC245fa.



### PHYSICAL PROPERTIES The physical properties of HFC-245fa are shown inTable 1. CFC-11, HCFC-141b, n-pentane and cyclopentane are included for comparative purposes. The molecular weight of HFC-245fa is approximately the same as that of CFC-11, therefore use levels in foams are aboutequal to those used with CFC-11 to achieve a given density. The boiling point of HFC-245fa is lower than those of the other blowing agents listed. This lower boiling point,and therefore higher vapor pressure at any given temperature, can provide significant improvement in certain foam properties, particularly at lower temperatures. The vapor pressure of HFC-245fa and other foam blowing agents as a function of temperature are shown in Figure 1. The higher vapor pressure of HFC-245fa impacts the processing and storage of premixes. The lower boilingpoint and higher vapor pressure of HFC-245fa have contributed to stronger foams with better k-factors over a range of temperatures. These issues are discussed in thesection in the report entitled k-Factor vs. Mean Temperature and Time.



### FIANEVIABILITY CHARACTERISTICS The ability of HFC-245fa to be used in existing foam processing equipment with minimum modifications is important. Currently, most rigid foam processing equipment is designed to handle either non-flammable or moderately flammable liquid blowing agents. HFC-245fa is considered "non-flammable" and has no flame limits. The flammability characteristics of HFC-245fa are given inTable 2. the flammabrlity properties of CFC-11, HCFC141b, cyclopentane, and n-pentane are included for comparison. Based on this test data, we believe HFC-245facan be used safely on all existing foam processing equipment. In fact, this material has successfully been used in low pressure, high pressure and spray equipment. It hasalso been successfully processed into refrigerator cabinets. The details will be discussed later in this paper.



### ENVIRONMENTAL PROPERTIES HFC-245fa is a non ozone depleting chemical

. The environmental properties of HFC-245fa are given in Table 3. Also included in the table are the data for HCFC-141b, CFC-11, cyclopentane and n-pentane. The atmospheric lifetimes of these blowing agent molecules is a key factor in the determination of these environmental properties. The Global Warming Potential (GWP) of HFC-245fa is relatively low compared to CFC products and other commercially available products today, such as HFC-134a, which leads us to believe that the GWP of HFC-245fa will be environmentally acceptable

. A recent reduction of the GWP of HFC-245fa has occurred due to a change in the atmospheric lifetime of methyl chloroform

. Because of its atmospheric lifetime an application to exempt HFC-245fa from being considered a VOC has been filed and we anticipate this exemption will be granted shortly. The assessment of GWP should not only be limited tothe direct contribution of the blowing agent such as HFC245fa
, but also the assessment of the indirect contribution of the carbon dioxide emissions resulting from the energy required to operate a system over its normal life. Thisanalysis is referred to as TEWI or "total equivalent warming impact". In spring of 1995
, The American Home Appliance Manufacturers (ARAM) conducted a trial with HFC

-245fa.The formulations used to produce these refrigerator cabinets were unoptimized. Refrigerators manufactured with HCFC- 141b were used as a control

. The cabinets were assembled and a DOE Cabinet Energy test and a Reverse

2 I Bogdan, Williams, Logsdon, Parker Table 1. Blowing agentphysicalproperties**,,~** HFC·245ta CFC·ll HCFC·141b Cyclopentane n·Pentane MolecularWeight 134.0 137.4 116.9 70.0 72.0 Boiling POint of 59.5 74.8 89.7 120.7 96.8 LIquId density, glee 068°F 1.32 1.49 124 0.75 0.63 Vapor Pressure, pSia @68°F 17.8 12.8 10.0 4.9 8.3 VaporThermal COndUctNrty.

BTU inlhrft'oF 0 111°F 0.097 0.064 0.084 BTU Inlhrft"F 0**~F** 0.061 0.072 0.063 0.104 Flame Limits. volume %, None- Nonel 7.6·17.7' 1.4·9.4' 1.3-8.' Flash POint. OF None None None ·35 .40**''''STME681,a~'COl'ldltlOM** matehlQl'lltlOO cltya!'**~** THI method nol**apeot~**

3C 60 70 00 100 110**~HFC·2.51.** -+-HCFC-1411) """'-CFC-11 -.-**C~ntane** Figure 1. Vaporpressures ofsome foam blowing agents



### HFC-245fa: Solubility, vapor pressure, a discussion ofthe effect of surfactants on foam properties, cell gas content, foam aging and k-factor vs. mean temperature. The paper concludes with a discussion ofAlliedSignal's plans for continuing development and commercialization of HFC245fa.



### PHYSICAL PROPERTIES

The physical properties of HFC-245fa are shown in Table 1. 

### CFC-ll, HCFC-141b, n-pentane and cyclopentane are included for comparative purposes. The molecular weight of HFC-245fa is approximately the same as that of CFC-ll therefore use levels in foams are about equal to those

### ~sed with CFC-ll to achieve a given density. The boiling point ofHFC-245fa is lower than those of the other blowing agents listed. This lower boiling point, and therefore higher vaporpressure at any given temperature, can provide significant improvement in certain foam properties, particularly at lower temperatures. The vapor pressure of HFC-245fa and other foam. blo.wing

.agents as a function oftemperature are shown m FIgure

1. 

### The higher vapor pressure of HFC-245fa impacts the processing and storage of premixes. The lower boiling point and higher vapor pressure ofHFC-245fa have contributed to stronger foams with better k-factors over a range oftemperatures. These issues are discussed in the section in the report entitled k-Factor vs. Mean Temperature and Time.



### FLAMMABILITY CHARACTERISTICS

The ability of HFC-245fa to be used in existing foam processing equipment with minimum modifications is



### 2 IBogdan, Williams, Logsdon, Parker Table 2. Blowing agent flammabilityproperties

Flash POInt, SF HFC-245ta CFC-1 I HCFC-14I b CycIopentane n·Pentane

T8g Closed Cup None None None ·35' (ASTM 05&-87) Setaflash Closed Tester None None None (ASTM D3828-B7) Tag Open Cup None None • None (ASTM 0310-B6) Vapor Flame Umns, Vol % None None 7.6-17.7' 1.4-9.4'

(ASTM E681-85) Minimum Ignition Energy, mj NlA NlA 18.000 0.2·0.3 Heat of Combusbon, kcaVmol 244 220 768 'Test methOd not apectfted

Il Ambtent conditions, match ignition

Table 3. Blowing agent environmentalproperties

HFC-245fa CFC-" HCFC-141b HFC-l34a i5iiiiiOOi!ntane Ozone Depletion Potential 0 I 0.11 0 0 Atmosphenc Lifetime**~ars** 8.4 50 9.4 I' Few08Vs Global Warmmg Potentia 100yrtime horwon (COr • 11 820 4000 630 1300 3 VOCStatus No No No No Yes All o.ta u:ept HFC-245fa data from Energy and GiobaI watn"III'Ig Impacts of Nof..cr'H{Jnd andNext Gerwrabon CFC and HCFC AItemIItJves· 11)9.4**~** NothUtytobe C:OtISIdered avee ·40'

1.3-8.0'

839

n.-Pentane 0 Few Days

3 Yes



### important. Currently, most rigid foam processing equipment is designed to handle either non-flammable or mm:;Ierately flammable liquid blowing agents.**HF~-~45fa** 

### IS considered "non-flammable" and has no flame lImIts. The flammability characteristics of HFC-245fa are given in Table 2. The flammabnity properties of CFC-ll, HCFC141b, cyclopentane, and n-pentane are included for comparison. Based on this test.**d~ta,** 

### we believe**~C-24~fa** 

### can be used safely on all eXIstmg foam processmg eqUIpment. In fact, this material has successfully been used m low pressure, high pressure and**s~ray** 

### equipment. It

### hB:s also been successfully processed mto refrigerator cabInets. The details will be discussed later in this paper.



### ENVIRONMENTAL PROPERTIES

HFC-245fa is a non ozone depleting chemical. The environmental properties ofHFC-245fa are given in Table 3. Also included in the table are the data for HCFC-141b, CFC-ll, cyclopentane and n-pentane.**Th~** 

### atmospheric lifetimes ofthese blowing agent molecules IS a key factor in the determination of these environmental properties. The GlobalWarmingPotential(GWP) ofHFC-245faisrelatively low compared to CFC products and other**comm~r** 

### cially available products today, such as HFC-134a,**~hICh** 

### leads us to believe that the GWP of HFC-245fa wIll be environmentally acceptable. A recent reduction of the GWP ofHFC-245fa has occurred due to a change in the atmospheric lifetime ofmethyl chloroform. Because ofits atmospheric lifetime an application to exempt**HFC-24~fa** 

### from being considered a VOC has been filed and we antIcipate this exemption will be granted shortly

. The assessment of GWP should not only be 

### limited to the direct contribution ofthe blowing agent such as HFC245fa, butalso theassessmentoftheindirectcontribution ofthe carbon dioxide emissions resulting from the energy required to operate a system over its normal life. This analysisisreferredto asTEWIor"totalequivalentwarmingimpact".

In spring of 1995, TheAmerican HomeAppliance Manufacturers (AHAM) conducted a trial with HFC-245fa. The formulations used 

### to produce these refrigerator cabinets were unoptimized. Refrigerators manufactured with HCFC-141b were used as a control. The cabinets were assembled and a DOE CabinetEnergytest and a Reverse 

### I 

# ITable 4. Results of AHAM refrigerator trial



# AHAM RE FR IGE RAT OR TRIAL

DOE Cabinet Energy
, Reverse Heat Leakage, KwH/day BTU/hr lowing agent HCFC-141b HFC-245fa HCFC-141b HFC-245fa

verage value 2.071 2.090 270.2 271.7
/o Increase vs 0.9 0.5 HCFC-141b

Table 5. TEW/ analysis AHAM refrigerator trial

120W

♦ Assumptions: 10Oyrtime horizion . 20 yr. appliame lifetime . 100% of HF -245fa xeleased after 20 yr. Con ibs ion fium tefrigernt (134a) is constant

Heat Leakage test were performed on each. The results are contained in Table 4. The refrigerators produced with HFC-245fa had equivalent energy performance to the ones produced with HCFC-141b even though there was a 5% higher k-factor for foams produced with HFC-245fa. This is why actual analysis of the foam in its application at the temperatures it will be exposed to is important.There is an extensive discussion of k-factor vs. mean temperature included in'a latter portion of this paper. If this energy data for the unoptimized refrigerators is combined with the GWP for HFC-245fa, a TEWI analysisof the refrigerators energy requirements can be calculated. The results are also displayed in Table 5. A comparison of the energy requirement for a refrigerator made with HFC-245fa, HCFC-141b and cyclopentane are included. It is important to understand the assumptions whichare made in this calculation. These include : the refrigerators are operational in North America, the 100 yr. GWPis used for each chemical to determine its direct contribution to global warming in terms of kg CO2 generated, the life of the appliance is assumed to be 20 years, at the end of the 20 year life all the blowing agent will be released tothe environment, and for the sake of consistency the fluorocarbon used as the compressor fluid in these examples is HFC-134a. The result is that the total requirements , both direct and indirect, to operate a refrigerator produced with the unoptimized HFC-245fa formulations has less TEWI in its lifetime than one produced with cyclopentane. Also, it requires approximately 8.3% less TEWI due to direct energy requirements to operate than one produced with cyclopentane. This is a critical concern in regions where a consistent supply of electricity or energy production Table 6. Summary of toxicity testing conducted on HFC-245fa to date

TEST HFC-245fa HCFC-141b n-Pentane Isopentane Cvclo ntane Acute Dermal LD,n> 2000 LD,,,> 2000 no LDw no LDsp no LD50

mg/kg mg/kg reported reported reported

No irritation No irritation Irritation Irritation Irritation noted noted noted noted noted Acute LC,a> Inhalation 101.300 ppm Screen- Mice Cardiac Negative at 10.000 ppm xxx xxx Weak Sensitization 10,000 and Threshold Sensitizer

20.000 m Human Weak Not active up zxx xxx xxx Lympocyte activity at to 35% v/v

30% v/v without S9 Mouse Not active at Not active up xxx xxx xxx Micronucleus 100,000 ppm to 36.000 PPM Ames Assay Not Active Not Active xxx Not Active xxx Acute (4) Hr LC,p> LCw- LCsp- xxx xxx Inhalation- 200,000 ppm 62,000 ppm 11.260 ppm Rats
xxx- Test results not reported Note: No exposure level was reported for cyclopentane only a classification as a weak sensitizer

capacity is not adequate enough to meet the needs of the population. Additional improvements in the performanceof HFC-245fa foam can,, be expected as formulation optimization is done over the next few years. Hence, the energy consumption of refrigerators prepared with HFC-245fa should be even lower. This points out the importance ofnot only considering the direct chemical effect of a substance,but also considering the total energy requirements of the system in which it is used. In addition to the environmental aspects, the discussion of the long term breakdown products of CFC substitutes, into trifluoroacetic acid (TFA) has been occurring.Research work has recently been completed which identifies the long term breakdown products of HFC-245fa as HF and CO2. Therefore, the use of HFC-245fa does not lead to the formation of TFA in the environment.



### TOXICOLOGICAL PROPERTIES It is critical that the toxicity of any alternative foam blowing agent candidate be fully defined. This data is required not only to set industrial exposure guidelines during storage, handling, and use of the blowing agentduring the foam manufacturing process, but is also important in risk assessment analyses of the final foam product in its intended use and is critical to considerations in product stewardship and responsible care. The HCFC and HFC molecules commercialized over the past several years, including HCFC-141b, have been extensively tested for toxicity characteristics. HFC-245fa is currently undergoing a similar toxicity testing protocol.A summary of the toxicity testing conducted on HFC245fa to date is included in Table 6. Data on HCFC-141b and hydrocarbons is also included for comparison. The test results support that HFC-245fa has a very low order of acute toxicity equivalent to or better than those, reported for HCFC-141b. We are continuing our toxicity testing and have summarized in Table 7 our anticipated work. We anticipate the results of the 28 day inhalationand 13 week inhalation study with HFC-245fa to be completed in 1996.

Bogdan
, Williams, Logsdon, Parker / 3 Table 4. Results of AHAM refrigerator trial 

# AHAM RE FRIGE RAT

# OR TRIAL

DOE Cabinet Energy. Reverse Heat Leakage, KwH/day BTU/hr Blowing agent HCFC-141b HFC-245fa HCFC-141b HFC-245fa
Average value 2.071 2.090 270.2 271.7

Yo Increase vs 0.9 0.5

HCFC-141b

Table 5. TEWI analysis AHAM refrigerator trial

• Assumptions:

• 100yrtimemrizion

• 20yr. appliaD::e lifetime

• 100% ofHFC-245famlemed

afulr2Oyr.

• Contributionfromrefrigerant

(l34a)isconstant



### Heat Leakage test were performed on each. The results
are contained in Table 4. The refrigerators produced with HFC-245fa had equivalent energy performance to the
ones produced with HCFC-141b even though there was a 5% higher k-factor for foams produced with HFC-245fa. This is why actual analysis ofthe foam in its application at the temperatures it will be exposed to is important. There is an extensive discussion ofk-factor vs. mean temperature included in'a latter portion ofthis paper.

Ifthis energy data for the unoptimized refrigerators is combined with the GWP for HFC-245fa, a TEWI analysis ofthe refrigerators energy requirements can be calculated. The results are also displayed in Table 5. A comparison of the energy requirement for a refrigerator made with HFC-245fa, HCFC-141b and cyclopentane are included.

It is important to understand the assumptions which
are made in this calculation. These include : the refrigerators are operational in North America, the 100 yr. 

### GWP is used for each chemical to determine its direct contribution to global warming in terms ofkg CO2 

### generated, the life ofthe appliance is assumed to be 20 years, at the end ofthe 20 yearlife all the blowing agentwill be released to the environment, and for the sake ofconsistency the fluorocarbon used as the compressor fluid in these examples is HFC-134a.

The result is that the total requirements
, both direct and indirect, to operate a refrigerator produced with the unoptimized HFC-245fa formulations has less TEWI in its lifetime than one produced with cyclopentane. Also, it requires approximately 8.3% less**T~WI** 

### due to direct energy requirements to operate than one produced with cyclopentane. This is a critical concern in regions where a consistent supply of electricity or energy production Table 6. Summary of toxicity testing conducted on HFC-24Sfa to date

TEST HFC-245fa HCFC-14Ib D-Pentane Isopenlane Cvclopenla..., Acute Dennal LD",>2ooo LD",> 2000 noLDso noLO,. noLD", mg/l<g mg/l<g reponed reponed reponed

No irritation Noinitalion Irritation Irritation Irritation noted noted noted noted noted Acute LC,.> Inhalation 101.300 ppm Screen- Mice Cardl3c Negauveat 10.000ppm xxx xxx Weak Sensitization 10.000 and Threshold Sensitizer 20.000 ppm Human Weak NOI active up xxx xxx xxx Lympocyte activity at to 35% vlv 3O'k vlv without 59 Mouse Not active at Not active up xxx xxx xxx Micronucleus 100.000ppm to 36.000

. ppm Ames Assay Not Active Not Active xxx Not Active xx> Acute (4) Hr LC,.> LC,.- LC,.- xxx xxx Inhalatlon- 200.000 ppm 62.000 ppm 11.260ppm Rats

xxx- Test results not reponed Note: No exposure level wasreponed forcyclopentane only a classificalJon as a weak sensitizer



### capacity is not adequate enough to meet the needs ofthe population. Additional improvements in the performance of**HFC-2~5fa** 

### foam cap,be expected as formulation optimizationis done over the nextfew years. Hence, the energy consumption ofrefrigerators prepared with HFC-245fa should be even lower. This points out the importance of not only considering the direct chemical effect of a sub- .' stance.but also considering the total energyrequirements ofthe system in which it is used.

In addition to the environmental aspects, the discussion ofthe long term breakdown products ofCFC substitutes, into trifluoroacetic acid (TFA) has been occurring. Research work has recently been completed which identifies the long term breakdown products of HFC-245fa as HF and CO2, 

### Therefore, the use of HFC-245fa does not lead to the formation ofTFAin the environment.



### TOXICOLOGICAL PROPERTIES It 

### is critical that the toxicity of any alternative foam blowing agent candidate be fully defined. This data is required not only to set industrial exposure guidelines during storage, handling, and use of the blowing agent duringthe foam manufacturingprocess, butis also importantinrisk assessment analyses ofthefinal foam product in its intended use and is critical to considerations in product stewardship and responsible care.

The HCFC andHFC molecules commercialized overthe past several years, including HCFC-141b, have been extensively tested for toxicity characteristics. HFC-245fa is currentlyundergoing a similartoxicitytestingprotocol. A summary of the toxicity testing conducted on HFC245fa to date is included in Table 6. Data on HCFC-141b and hydrocarbons is also included for comparison.

The testresults supportthat HFC-245fahas a very low order ofacute toxicity equivalent to or better than those. reported for HCFC-141b. We are continuing our toxicity testing and have summarized in Table 7 our anticipated work. We anticipate the results ofthe 28 day inhalation and 13 week inhalation study with HFC-245fa to be completed in 1996.



### Bogdan, Williams, Logsdon, Parker I 

### 3Table 7. Additional toxicological studies

Planned Studies • 28 Day Inhalation • 13 Week Inhalation • Rat & Rabbit Teratology • Environmental

• Octanol/water partition coefficient • Algae • Daphnia • Fish Optional Studies • Reproductive toxicity • Sub-chronic toxicity • Repeated dose studies • Global compliance

Table 8. HFC-245fa compatibility with plastics and elastomers

Compatible Not Compatible • Polyethylene • Nitrile ( marginal) • Polypropylene • HNBR • PTFE • Viton • EPDM • Epichlorohydrin
• Neoprene • Buna-N Material is immersed inIIFC-245fa for 2 weeks at room temperature Pass/Fail Criteriar Swelling < 20& or shrinkage < 5%

Table 9. Formulations for base premix

Premix pb% Thanol R470X` ' 100 Ttab B8466' 1.5 D DR81720 '' 1.0 Premix blowing agent ratio (75/25 wt%) Eastman Chemical o' Huntsman Chemical "'Air Products & Chemicals



### THERMAL AND HYDROLYTIC STABILITY In our previous paper(I), we reported that HFC-245fa has been evaluated for storage stability at temperaturesup to 200°C with no evidence of blowing agent decomposition. This testing was done on neat HFC-245fa, HFC245fa with 300 ppm water added, and both neat and "wet" HFC-245fa in the presence of 302 stainless steel, 3003 aluminum, or both. Additional testing has been done with cold rolled steel, brass and lead with similar results. Limited testing has also been completed on several gasket materials and plastics. These results are summarized in Table 8. It is important to note that these tests represent thesuitability for contact of these materials with neat HFC245fa and do not necessarily represent their suitability for contact with "B-components" containing HFC-245fa as isthe case in foam processing equipment. A test was conducted immersing Viton gasket material at room temperature for 2 weeks to neat samples of CFC-11SBA, HCFC14lb and HFC-245fa and also to neat "B-components" and "B-components" containing each of the blowing agents. The formulation for the "B-components" used is contained in Table 9. The results of the testing are contained in Table 10. Although only weight gain is reported in this paper other dimensional measurements were also taken. The data for length, width and hardness follow the sametrend as weight. Therefore, before using any "B-components" in equipment independent of blowing agent it ishighly recommended that a brief stability test be conducted on the "wetted" gaskets and seals in the unit.



### POLYOL SOLUBILITY Solubility of a blowing agent is a critical variable in the foaming reaction. It is determines both the density andinsulation properties of the foam. The solubility of HFC245fa was tested in various polyols and polyol blends. The

4 if Bogdan, Williams, Logsdon, Parker Table 10. Compatibility of viton gasket with blowing agents and blowing agent premix formulations

Piton Gasket Compatibility

HFC-245fa

HCFC-141b

CFC-11SBA

premix



### 0 5 10 % Weight Gain 15 OBA & Premix

n Neat Blowing agent

Table 11 . Resin formulations

Resin II Coat nt pbw 1 Pluracol 975 ' 100

Te ostabB-8404 1.5 Pol cat 8 - 2.5 2 Terate 254 100

8 8408 ' 2 O K-15 ' M Z 3 DABCO TMR-30 0.5

Water 0.5 Thah R-470X ' 100 LK-443 I DABCO R-8020 1 4 Multmol 4063 " ' too

Te ostab B-8461 1.5 Polycat 8 2.5 "BASF Goldschmidt Chemical "'Air Products & Chemicals ''Eastman Chemical "'Bayer

Men 4

Men 3
Mein 2

Men1

Kneel 975

824
V°ranot 390

T aW R-470X

Taroi 235

Taste 2541

Taste 254°

Tana 203

Muaranol 4063 Table 12.
Solubility of HFC-245fa In Polyois and Resins

0 10 20 30 40 50 60 70

HFC-245fa Dlasoived phpp

polyol blends tested , listed in Table 11, represent a typical spray, appliance, PIR and panel formulation. A knownamount of polyol or resin and an excess amount of HFC245fa was added to a calibrated tube. The tubes weresealed and allowed to equilibrate for 24 hours. If separation occurred the height of the blowing agent was measured and the amount dissolved in the polyol was calculated. The data available to date is summarized in Table 12. Additional testing is currently in progress and will be presented as it becomes available. Table 7. Additional toxicologicalstudies

Planned Studies Studies

• 28 Day Inhalation • Reproductive toxlcny

• 13 Week Inhalation • Sub-chronic toxicity

• Rat & Rabbit Tenttolog) • Repeated dose siudies

• Environmental • Global comphance

• OctanollwaterpanJuon coefficient

• Algae

• Daphnia

• FISh

Table 8. HFC-24Sfa compatibility with plastics and elastomers

Comoalible Not Compatible 

## • Polyethylene 

## • Nitrile ( marginal) 

## • Polypropylene 

## • HNBR 

## • PTFE 

## • Vuon 

## • EPDM 

## • Epichlorohydrin 

## • Neoprene 

## • Buna·N 

# · Malenal is immersed mHFC-24Sfa for 2 weeks at room temperature 

# · PassIF.il Criteria' Swelhng < 20,. or shnnkage < 5'"

Table 9. Formulations forbase premix

Premix Thanol R470X' , Tet20stab B8466 • Dabco R8020 .' Premix blowillg agnt ratio (75125 wr%) " Eastman Cherrucal c! Huntsman Chemical

L" Air Products & Chemicals pb

.. 100 1.5 1.0



### THERMALAND HYDROLYTIC STABILITY

In our previous paper(I1, we reported that HFC-245fa has been evaluated for storage stability at temperatures up to 200°C with no evidence ofblowing agent decomposition. This testing was done on neat HFC-245fa, HFC245fa with 300ppmwateradded, andboth neatand "wet" HFC-245fa in the presence of 302 stainless steel, 3003 aluminum, or both. Additional testing has been done with cold rolled steel, brass and lead with similar results. Limited testinghas also been completed on several gasket materials and plastics. These results are summarized in Table 8.

It is important to note that these tests represent the suitability for contact ofthese materials with neat HFC245fa and do notnecessarilyrepresenttheir suitabilityfor contact with "B-components" containing HFC-245fa as is the case in foam processing equipment. A test was conducted immersingViton gasket material at room temperature for 2 weeks to neat samples ofCFC-llSBA, HCFC141b andHFC-245fa and also to neat "B-components" and "B-components" containing each of the blowing agents. The formulation for the "B-components" used is contained in Table 9. The results of the testing are contained in Table 10. Although only weight gain is reported in this paper other dimensional measurements were also taken. The data for length, width and hardness follow the same trend as weight. Therefore, before using any "B-components" in equipment independent of blowing agent it is highlyrecommended that a briefstabilitytestbe conducted on the "wetted" gaskets and seals in the unit.



### POLYOL SOLUBILITY

Solubilityofa blowing agent is a critical variable in the foaming reaction. 

### It is determines both the density and insulation properties ofthe foam. The solubility ofHFC245fa was tested invarious polyols and polyol blends. The



### 4 IBogdan, Wl1liams, Logsdon, Parker : Table 10. Compatibility ofviton gasket with blowing agents and blowing agentpremix formulations
VitO" Gasket Compatibility

I I HFC-245fa

# -

HCFC-141b OBA. Premix

CFC-11SBA • Neat Blowing agent

premix



### o 5 10 15
% Weight Gain

Table 11. Resin formulations

Resin #

I

2

'.

4

" BASF (2)GoJdschmidl Chemical

!3!Air Products & Chemlca1s

141Eastman Chemical CSJBayer Component Pluracol 97S

. TegostabB-8404 w Polyeat8

. Telate 254 Tegostab B-8408 • DABCO K·15 '" DABCO 1MR-30'" Water ThaholR-470X «. LK-443 ." DABCO R-8020 '" Multranol 4063 '" Tegostab B-8461 ., Polvcat 8 '"

Table 12. pbw 100 1.5 2.5 100 2 3 0.5 0.5 100 I I 100 1.5 2.5

Solubilityof HFC-245fa In PoIyoIs and Realns**~3 ~2** 

Piuraco{ 975
_824

Thanol R-4&70X
T_0I235

Terato 25(1

Tertto 2S4c

T

.....203

Munraool <4063**~**



### o 10 20 30 40 50 60

HFC-245fa DluolVedphpp 70

polyol blends tested, listed in Table 11, represent a typi-

.cal spray, appliance,PIRand panelformulation.Aknown amount ofpolyol or resin and an excess amountofHFC245fa was added to a calibrated tube. The tubes were sealed and allowed to equilibrate for 24 hours. Ifseparation occurred the height ofthe blowing agent was measured and the amount dissolved in the'polyol was calculated.- The data available to date is summarized in Table 12. Additional testing is currentlyin progress and will be presented as itbecomes available.Table 13. Raw materials and blends used for blowing agent stabilii -y testing

MATERIAL WT RATIO TESTED (COMPONENT : HFC-245fa Pol ols 70:30 Catalysts 1:10 Surfactants 1:15 Com atibilizers 1:7 MDI 1:10

Table 14. Raw material chemical stability data
Component Unaffected Affected Catalysts Polycat 5 DABCO K-15 DABCO TMR-30' Polycat 46' Curithane 52' -DABCO TMR DABCO TMR-2 DABCO TMR-3 Compatibilizers N-10- N-95 ' MD1 Lupranate M-20S' Lupranate M-70L' Mondur MR' Papi 27' Rubmate M" Surfactants L5100
L5110 Y 10774 L6900 L5440 DC-9342' DC-5357' LK-443 ' Tegostab B-8404 Tegostab B-8458 Tegostab B-8467 Tegostab B-8465' Te ostab B-84PI Patrols Voranol 360 Voranol V370' Voranol V490' Thanol R-575' Thanol R-370` Thanol R-42

20' Thanol R-470X' Terate 2541` Thanol R-650X' Stepanol 2352" Thanol SF-265'

Notes I Air Products & Chemicals 7. Goldschmidt Chemical 2. Huntsman Chemical 8. Eastman Chemical 3. BASF 9, Hoechst-Celanese 4 Bayer 10. Stepan Co 5 Dow Chemical 6 ICI
Solubility of the blowing agent in the "B-components" is not only a function of its solubility in the polyol but also is influenced by the surfactant used in the formulation This is further discussed in the Surfactant portion of this report.



### COMPATIBILITY WITH FOAM RAW MATERIALSIn our previous papers' 1i, we have reported some limited data on compatibility of various raw materials with HFC-245fa. Additional raw materials have been tested and the results shown in Table 14. A series of sealed tube studies were done to determine the stability of HFC-245fa in the presence of certain polyurethane raw materials. Each raw material was mixed with HFC-245fa in a weight ratio similar to that which would be typically be found in a blended polyol component and placed in sealed glass tubes. The ratios used are listed in Table 13. The tubes were then placed in a 300 °F oven for 24 hours. The test was run under these conditions to simulate the exotherm temperature during the manufacture of a polyurethanefoam. The tubes were removed from the oven and the contents analyzed for decomposition products by gas chromatography. a CFC- I I Vapor Pressure at 130 F 40-, / 35 a- / 30 

## I-e 25 130 F / lo, 20 / 15 70F 10a

5

0 /



### 0 5 10 1s 20

Wt. % HFC

-245fa in P824 Figure 2. Vapor pressure HFC-245fa in P824

The chemical decomposition of a blowing agent such as HFC-245fa produces a mineral acid (HF) which is reactive with catalysts in a premix system and thus can influence foam reactivity. This decomposition reaction can occur during extended storage of a premix or during the foam reaction. Since the premix is a mixture of materials , thereis obvious synergy between the components which influence the chemical reactions that occur during the foaming process and the storage 'of the premix. This test however does not take this into account . It was designed to detect any reaction between the HFC-245fa and any single raw material only.The affected substances are catalysts. During the introduction of HCFC-141b, it was discovered that use of potassium carboxylate catalysts such as DABCO K-15* resulted in increased levels of decomposition products in the cell gas of foams produced with HCFC-141b. This reaction was primarily found to occur in polyisocyanuratefoams (31 DABCO K-15* was found to be chemically reactive with HFC-245fa and isocyanates under the test conditions. This test determines the chemical sensitivity betweenHFC-245fa and raw materials which is an important consideration. However, the critical concern is what occurs in the final foam product. This is discussed in detail along with the results of toxicity testing on HFC-1234ze in a later portion of this paper.

PREMIX AND POLYOL VAPOR PRESSUREFrom both an environmental and a processing perspective the vapor pressure of the premix is critical. It is a key part of determining how to effectively minimize fugitiveemissions as well as defining the type of container necessary for shipment and storage of a system. Two types of vapor pressures measurements have been taken vapor pressure vs. blowing agent concentration and vapor pressure vs. temperature. The measurement ofvapor pressure vs. blowing agent concentration gives insight into processing parameters and how to minimize fugitive emissions. Figure 2 contains a graph of vapor pressure vs. wt. % HFC-245fa in Pluracol 824. The vaporpressure of HFC-245fa blend is lower than the vapor pressure of neat CFC-11 at concentration of less than 20 % at 70 °F. Therefore, if the blowing agent is added to a cooled premix (i.e. below the boiling point of HFC-245fa) fugitive

* Air Products

Bogdan, Williams, Logsdon, Parker / 5 'Table 13. Raw materials and blends used for blowing agent stabili!Jt testing

MATERIAL WT RATIO TESTED (COMPONENT: HFC·Z4Sfa I Polvol, 70:30 Catalvsts 1:10 Surfactant!. 1:15 CompatibilJzen. L7 MDI I:JO

Table 14. Raw material chemical stabilitydata

Comoonenl CaJaiysls

Compatibiliurs

MDi

Surfactant!

Polyols**~ote!'.** J AIr**Product~** & Chemlcah .2 Huntsman Chemrcal 3. BASF 4 Bayer 5 Dow ChemIcal 6 ICI Unallected Affected Polycar 5**DABCOK-I~** DABCO TMR-30' POIYC3[ 46!

Curithane**52~** ·DABCO TMR DABCO TMR-2 DABCO TMR·' N-IO' N-95' Lupranale M-20S' Lupranate M-70L3

Mondur MR4

Pap'**27~** Rubmate MtL5100 L51 JO YI0774 L6900 L5440 DC-934i DC-5357' LK-443 ' Tegostab B-8404 Tegostab B-8458 Tegostab B-8467 Tegostab B-8465**~** TegoSlab B-84PI

Voranol360 VaranoI \,370' Varanol V490' Thanol R-575' Thanol R-370' Thanal R-42(lf Thanol R-470X'

T erate 254 J"- Thanol R-650X' Stepano! 2352 il Thana! SF·26S·

7 Golds.chmidt Chemlcaj 8. Eastman Chemical 9, Hoechst-Celane3c 10 Stepan Co



### Solubility ofthe blowing agent in the "B-components" is not only a function ofits solubility in the polyol but also is influenced by the surfactant used in the formulation This is further discussed in the Surfactant portion of this report.



### COMPATIBILITYWITH FOAM RAW MATERIALS

In our previous papers <11, 

### we have reported some limited data on compatibility of various raw materials with HFC-245fa. Additional raw materials have been tested and the results shown in Table 14. A series ofsealed tube studies were done to determine the stabilityofHFC-245fa in the presence of certain polyurethane raw materials. Eachraw materialwasmixed with HFC-245fain a weight ratio similar to that which would be typically befound in
a blended polyol component and placed in sealed glass tubes. The ratios used are listed in Table 13. The tubes
were then placed in a 300 

### of oven for 24 hours. The test
was run under these conditions to simulate the exotherm temperature during the manufacture of a polyurethane foam. The tubes were removed from the oven and the contents analyzed for decomposition products by gas chromatography. CFC· I I VaporPressure at 130 F 40



# .

# -.

# --

# ..-----

# -.-

# --

# -.

# -,- - - - - 

# -

# .. 35

...... 30 .!!! 

# ! 25 

### f 20

== CI) CI) 15 f Q. 10
5
0 0 / / / 

### ,- / / ,- 

### ,,/

5 ,- I30F ,-

,- ,- 

### /'

10 

# ,. 

# ,. ,. ,. ,.

Wt. % HFC-245fa In P824 15

Figure2. Vaporpressure HFC-245fa in P824 20



### The chemical decomposition ofa blowing agent such as HFC-245fa produces a mineral acid (HF) whichisreactive with catalysts in a premix system and thus can influence foam reactivity. This decomposition reaction can occur during extended storage of a premix or during the foam reaction. Sincethepremixis a mixture ofmaterials
,there is obvious synergy between the components which influence the chemical reactipns that occur duringthe foaming process iUld the storage·ofthe premix. This test ,however does not take this into account. It

### was designed to detect any reaction between the HFC-245fa and any single raw material only.

.

The affected substances are catalysts. Duringthe introduction of HCFC-141b, it was discovered that use of potassium carboxylate catalysts such as DABCO K-15* resulted in increased levels ofdecomposition products in the cell gas of foams produced with HCFC-141b. This reaction was primarilyfound to occur in polyisocyanurate foams.(3) DABCO K-15* was found to be chemically reactive with HFC-245fa and isocyanates under the test conditions.

This test determines the chemical sensitivity between HFC-245fa and raw materials which is an important consideration. However, the critical concern is what occurs in the final foam product. This is discussed in detail along with the results of toxicity testing on HFC-1234ze in a later portion ofthis paper.



### PREMIXAND POLYOLVAPOR PRESSURE

From both an environmental and a processing perspective the vapor pressure ofthe premix is critical. It

### is a key part of determining how to effectively minimize fugitive emissions as well as defining the type ofcontainer necessaryfor shipment and storage ofa system.

'!\vo types ofvapor pressures measurements have been taken vaporpressurevs. blowing agent concentration and vapor pressure vs. temperature. The measurement of vapor pressure vs. blowing agent concentration gives insight into processing parameters and how to minimize fugitive emissions. Figure 2 contains a graph of vapor pressure vs. 

### wt. % 

### HFC-245fa in Pluracol 824. The vapor pressure ofHFC-245fablendislowerthanthevaporpressure ofneat CFC-ll at concentration ofless than 20 % 

### at 70 OF. Therefore, ifthe blowing agent is added 

### to a cooled premix (i.e. below theboilingpointofHFC-245fa)fugitive

*Air Products



### Bogdan, Williams, Logsdon, Parker I 5Table 15. Premix andblowing agent concentration

Premix Concentration 66% Polyether 65% Polyester 72% Sucrose HFC-245fa Concentration 34% 35% 28%

emissions should be minimal. This was demonstrated in a recent AHAM refrigerator trial where HFC-245fa wasadded subsurface to a precooled premix in an open processing tank . Typically premix blending is done in closed containers. Therefore, the loss of less than 4% during the mixing of the blowing agent into the premix and the transfer of the premix into the tanks of the processing equipment is considered excellent.Vapor pressure measurements are also useful in determining the appropriate shipping containers . Vapor pressure is a very critical concern in the systems business because currently a significant portion of the systems soldare shipped in drums or totebins. These containers traditionally have low pressure ratings. The vapor- pressure ofthree commercial spray foam systems containing HFC245fa were measured. These were sucrose, polyether andpolyester polyol spray formulations. The premix and blowing agent concentrations are listed in Table 15. The containers were filled to 93% of capacity to simulate drum storage conditions. The results are contained in Table 16.There is a marked difference in vapor pressure of the systems tested. It is in part due to the different quantity of HFC-245fa dissolved in each. At the low temperature of 50°F all three systems have similar vapor pressures. This supports the findings thatfugitive emissions should not pose a problem at processing temperatures below 60°F. However, at elevated temperatures the vapor pressure is directly proportional tothe quantity of HFC-245fa used in the system. The formulations exceed the vapor pressure rating of most totes (1 atm) at 68°F. Drum pressure ratings vary dependent upon the drum gauge chosen. This is an area where more data needs to be generated.



### STABILITY DURING THE FOAMING REACTION The stability of HFC-245fa during the foaming reactionis an area under study. It was discovered that under certain conditions during the foaming reaction it was possible for HCFC-141b to decompose into HCFC-1131a and HCFC-151a. The decomposition took place more readily inPIR than PUR foams and was highly correlated to the levels of potassium octoate present in the system.l3' A well defined research program has begun to identify what decomposition products, if any, were formed during foaming with HFC-245fa toxicity testing would then beconducted on these products and conditions which promote decomposition reactions would be identified. The initial foams produced with HFC-245fa were analyzed for cell gas content (4). Only one decomposition product was identified, HFC-1234ze ( 1,3,3,3 tetrafluoropropene). It is possible for this structure to exist in both a cis and a trans orientation. The decomposition reaction is shown in Table 17. Data on foams prepared from the Class I* and Class II* panel formulations and the spray formulation reported inour previous papers") (21 indicate that very little or no decomposition of the blowing agent occurs during the foamTable 16. Vapor pressure measurements vs temperature in spray foam formulations

0
50 59 68 77 86 95

Temperature ° F -POLYETTER ---POLYESTER -a- SUCROSE

Table 17

. Reaction mechanism for the formation of HFC-1234ze C F s - C H - C F C F, - C H = C F + H F H F C - 2 4 5 f a HFC -1 234ze

Table 18. Variables for decomposition study

Variable Level I Level 2 Trimer Catalyst DABCOTM K-15 ' DABCO" TMR-2 Reactivity Low- 50 sec Hi - 32 sec Index 250 350 Amine Catalyst DABCOTM TMR-30 Polycatt" 8" Polyol Stepanpol PS-2352 Terate 2541°' Blowing Agent Package 35 pbw HFC-245fa! 25 pbw HFC-245fa/ 0 pbw water I pbw water Air Products & Chemicals '''Stepan Chemical 13iHoerchst -Celanese

ing reaction. As with HCFC-141b, it was found that the decomposition reaction occurs primarily in PIR foams. It was also discovered that the reaction mechanism favored the formation of the trans isomer over the cis isomer in a 4:1 ratio. In response to this information, HFC-1234ze trans and HFC-1234ze cis isomers were purified and submitted for limited toxicity testing. Toxicity testing on HFC-1234ze trans isomer has been completed. The limited amount ofdata available on HFC-1234ze trans implies that it is not highly toxic or mutagenic. Toxicity testing is currently scheduled for the cis isomer.A new program was initiated to determine what conditions favored the decomposition reaction in polyisocyanurate foams. The program was modeled after the work completed with HCFC-141b13>. A series of 16 experiments were run to define the importance of 6 key variables.' The variables chosen were: trimer catalyst type [ potassiumcarboxylate, DABCOTm K-15(Tl) vs. a quaternary ammonium carboxylate DABCOT"' TMR-2 (T2)], reactivity [fast (R2) vs. slow (Rl) gel time] , foam index [250 (Il) vs. 350 (I2)], amine catalyst type [a volatile monoamine, N,Ndimethylcyclohexylamine, PolycatTM 8 (A2), vs. a less volatile triamine, DABCO T14TMR-30 (Al)], polyol type [StepanpolTM PS-2352 (Pl) vs. TerateTM 2541 (P2)], and blowing agent package [HFC-245fa only (Bl) vs. HFC245fa plus water (B2)]. Two levels or types of each variable were set They are shown in Table 18. This arrived

*This numerical flame spread is not intended to reflect hazards presented by this or any other under actual fire conditions.

6 / Bogdan, Williams, Logsdon, Parker Table 15. Premix andblowing agent concentration

Premix Concentration HFC·24sr. Concentration 669< Polvether 65% Polvester 35'K 72% Sucrose 281t

emissions should be minimal. This was demonstrated in a recent AHAM refrigerator trial where HFC-245fa was added subsurface to a precooled premix in an open processing tank

. Typically premix blendingis done in closed containers. Therefore, the loss ofless than 4% during the mixing of the blowing agent into the premix and the transfer of the premix into the tanks of the processing equipmentis considered excellent.

_

Vapor pressure measurements are also useful in determining the appropriate shipping containers. Vapor pressure is a very critical concern in the systems business because currently a significantportion ofthe systems sold
are shipped in drums or totebins. These containers traditionally have low pressure ratings. The vapor-pressure of three commercial spray foam systems containing HFC245fa were measured. These were sucrose, polyether and polyesterpolyol sprayformulations. Thepremixandblowing agent concentrations are listed in Table 15. The containers were filled to 93% of capacity to simulate drum storage condition!!. The results are contained in Table 16. There is a marked difference in vapor pressure ofthe systems tested. It is in part due to the different quantity of HFC-245fa dissolved in each.

At the low temperature of50°F all three systems have similar vapor pressures. This supports the findings that fugitive emissions should not pose a problem at processing temperatures below 60°F. However, at elevated temperatures the vapor pressure is directly proportional to the quantity of HFC-245fa used in the system. The formulations exceed the vapor pressure rating ofmost totes (1 atm) at 68°F. Drum pressure ratings vary dependent upon the drum gauge chosen. This is an area where more data needs to be generated:



### STABILITYDURING THE FOAMING REACTION

The stability ofHFC-245fa during the foaming reaction is an area under study. It was discovered that under certain conditions during the foaming reaction it was possible for HCFC-141b to decompose into HCFC-1131a and HCFC-151a. Thedecompositiontookplacemorereadilyin PIRthan PURfoams and was highly correlatedto the levels ofpotassium octoate present in the system.(3)

A well defined research program has begun to identify what decomposition products, ifany, were formed during foaming with HFC-245fa ,toxicity testing would then be conducted on these products and conditions which promote decompositionreactions would be identified. Theinitial foams produced with HFC-245fa were analyzed for cell gas content(4). Only one decomposition product was identified, HFC-1234ze ( 1,3,3,3 tetrafluoropropene). It is possible for this structureto existin botha cis and a trans orientation. The decomposition reaction is showninTable 17.

Data on foams preparedfrom the Class I* and Class II* panel formulations and the sprayformulation reported in
our previous papers(1) (2) indicate that very little or no decomposition ofthe blowing agent occurs during the foam

### 6 IBogdan, Williams, Logsdon, Parker Table 16. Vaporpressure measurements 

### vs temperature in spray foam formulations


### 30

# T------------------------------

c;- 25 iii 

### 20 

# .e: CII 

### 15 

# .. ::J III III 

### 10 CII 

# .. Q. 

### 5**O+-----~----~----~----_r----~** 

### 50 59 

### 68 77 

### 86 95 Temperature 0 F I--POLYETHER --POLYESTER --SUCROSE!

Table 17. Reaction mechanism for the formation ofHFC-1234ze
CF 3 ·CH 2 ·CF CF 3 -CH=CF+HF

HFC-245fa HFC-1234ze

;fable 18. Variables for decomposition study

Variable Tnmer Catalyst Reactivity Index Amine Catalyst Polvol Bl;wing Agent Package

01Air Products & Chemicals**/~I**Stepan Chemical

01Hoerchst -Celanese Level J DABCO'" K-15 ,"

Low- 50sec 250 DABCO'"TMR·30'" Stepanpol PS·2352 ," 35 pbw HFC-245fa/

opbw water Levell DABCOTMTMR·2' '
Hi

- 32 sec

350 PoJycatTt.t 8<: Terate 2541°> 25 pbw HFC-24Sfa/ 1pbw wafer

ing reaction. As with HCFC-141b, it was found that the decomposition reaction occurs primarily in PIRfoams. It
was also discovered that the reaction mechanism favored the formation ofthe trans isomer over the cis isomer in a 4:1 ratio, In response to this information, HFC-1234ze trans and HFC-1234ze cis isomers were purified and submitted for limited toxicity testing. 1bxicity testing on HFC-1234ze trans isomerhas been completed. The limited amountofdata available on HFC-1234ze trans implies that itis not highly toxic or mutagenic. 1bxicitytesting is currently scheduled for the cis isomer.

A new program was initiated to determine what conditions favored the decomposition reaction in polyisocyanurate foams. Theprogramwasmodeled aftertheworkcompleted with HCFC-141b(3). A series of 16 experiments
were runto define the importance of6 keyvariables.'The variables chosen were: trimer catalyst type [ potassium carboxylate, DABCOTM K-15(T1) vs. a quaternary ammonium carboxylate DABCOTM TMR-2 (T2)], reactivity [fast (R2) vs. slow (R1) gel time]
, foam index [250 (Il) vs. 350 (12)], amine catalyst type [a volatile monoamine, N,Ndimethylcyclohexylamine, PolycatTM 8 (A2), vs. a less volatile triamine, DABCO TMTMR-30 (AI)], polyol type [StepanpolTM PS-2352 (PI) vs. ThrateTM 2541 (P2)], and blowing agent package lHFC-245fa only (B1) vs. HFC245fa plus water (B2)]. Two levels or types ofeach variable were set. They are shown in Table 18. This arrived

*This numerical flame spreadis not intended to reflecthazards presented by this or any other under actual fire conditions. '° Table 19. 16 Experiments for study on formation of HFC-1234ze

I of water Index amine trimer time 1 stepan 0 250 tmr30 k15 50 2 terate 1 250 k15 50 3 stepan 1 350 tmr3O k15 50 4 terate 0 350 pc8 k15 50 5 terate 1 250 tmr30 k15 30 6 stepan 0 250 k15 30 7 terate 0 350 tmr30 k15 30 8 stepan 1 350 PC8 k15 30 9 terate 1 250 tmr30 tmr2 50 10 stepan 0 250 PC8 tmr2 50 11 terate 0 350 tmr30 tmr2 50 12 stepan 1 350 c8 tmr2 50 13 stepan 0 250 tmr30 tmr2 30 14 terate 1 250 tmr2 30 15 ste an 1 350 tmr30 tm12 30 16 terate 0 350 tmr2 30 Stepan refers to Stepanol PS-2352 Terate refers to Terate 2541

HI

Lou Y. wara uimc amne amt Figure 4. Analysis ofexperimental data

at the 16 experiments listed in Table 19. On each foam reactivity, cell gas content, peak exotherm and density were determined. Analysis of the data using the Taguchimethod yield s the results in Figure 4. Each point represents an average for all the, experimental results for that variable.Based upon experimental error analysis, the two variables of the six tested with the strongest effect to produce the HFC-1234ze trans isomer is reaction time and trimer concentration level. In experiments where the reactiontime was 30 seconds and DABCO K-15 was used, the levels of HFC-1234ze trans produced were on average two times higher than in reactions where the reaction timewas 50 seconds and DABCO TMR-2 was used. It is important to realize that in any reaction the catalyst levels are what determines the reactivity of the system. Therefore, these should not be considered independent effects as also the case with the *amine catalyst and index results. This study is continuing to determine if there is any effect on the HFC-1234ze trans levels in the foam as it ages. It isimportant to note here that under these conditions HFC1234ze trans can be generated but the limited toxicity data indicates that HFC-1234ze trans does not appear to be highly toxic or mutagenic.

SURFACTANTS Considerable work has been conducted over the pastseveral months to further define the performance of HFC245fa as a foam blowing agent. The choice of surfactant is Table 20. Formulation used for surfactant evaluation

component Pbw B- component Voranol 370 70 Tero1375 " 30 Polycat 5 0.7 Polycat41 0.5
Water 1.0 Surfactant 2.5 HFC-245fa 24 A-component Mondur MR 129 Index 125 Temperature 60 ° F

"'Dow Chemical '2 oXID Incorporated Air Products & Chemicals Bayer

80 r Table 21 . Surfactant vs. closed cell content

B8404 B8409 B8418 88433 88462

Surfactant

a critical part of optimization of the k-factor of a foam. Inthe transition from CFC-11 to HCFC-141b, it was discovered that the best foam performance in terms of both kfactor and physical properties was achieved with the use of different surfactants. Some very preliminary work has been completed using Goldschmidt surfactants studyingthe effect different surfactants have on the physical properties of foams produced with HFC-245fa. The initial work was done with the appliance formulation listed in Table 20. The foam was produced in L-molds and samples were taken to determine the effect each surfactant had on closed cell content, k-factor, flow and physical properties. The tests suggest the use of Goldschmidt B8404 and B8462 produced foams with higher closed cell contents (Table 21) and lower k-factors than those produced with other surfactants (Table 22). They also produced foams with better flowability (Table 23) and physical properties than other Goldschmidt surfactants. As a result of this work, the use of Goldschmidt B8404 and B8462 werefound to perform better than other Goldschmidt surfactants tested. Similar work has been completed on a series of OSi surfactants. To date OSi surfactant L-6900 appearsto be the best of the Osi surfactants tested. Additional surfactant screening is currently in progress and will be reported in subsequent papers.



### K-FACTOR VS TIME AND MEAN TEMPERATURE We have previously reported that foams produced with HFC-245fa age at a slower rate than foams produced with

Bogdan, Williams, Logsdon, Parker / 7 , :rable 19. 16 Experiments forstudy on formation ofHFC-1234ze j oolvol water 1 stepan 0 2 terate 1 3 stepan 1 4 terate 0 5 terate 1 6 stepan 0 7 terate 0 8 stepan 1 9 terate 1 10 stepan 0 11 terate 0 12 stepan 1 13 stepan 0 14 terate 1 15 stepan 1 16 terate 0 Stepan refers to Stepanol PS-2352 Terate refers to Terate 2541 Index amine 250 tmr30 250 oc8 350 tmr30 350 oc8 250 tmr30 250 oc8 350 tmr30 350 oc8 250 tmr30 250 oc8 350 tmr30 350 pcB 250 tmr30 250 oc8 350 tmr30 350 oc8

Main Effects for HFC-1234ze trans

HI trimer time k15 50 k15 50 k15 50 k15 50 k15 30 k15 30 k15 30 k15 30 tmr2 50 tmr2 50 tmr2 50 tmr2 50 tmr2 30 tmr2 30 tmr2 30 tmr2 30

# ·--·~/·\··················

LOW polyoJ lure Figure 4. Analysis ofexperimental data



### at the 16 experiments listed in Table 19. On each foam reactivity, cell gas content, peak exotherm and density
were determined. Analysis ofthe data using the Taguchi method yield s the results in Figure 4. Each point represents an average for all the. experimental results for that variable.

Based upon experimental error analysis, the two variables ofthe six tested with the strongesteffect to produce the HFC-1234ze trans isomer is reaction time and trimer concentration level. In experiments where the reaction time was 30 seconds and DABCO K-15 was used, the levels of HFC-1234ze trans produced were on average two times higher than in reactions where the reaction time
was 50 seconds andDABCO TMR-2 was used. Itis important to realize that in any reaction the catalyst levels are what determines the reactivity of the system. Therefore, these should notbe considered independenteffects as also the case with the'amine catalyst and index results. This study is continuing to determine ifthere is any effect on the HFC-1234ze trans levels in the foam as it ages. It 

### is important to note here that under these conditions HFC1234ze trans can be generated but the limited toxicity data indicates that HFC-1234ze trans does not appear to be highly toxic or mutagenic.



### SURFACTANTS

Considerable work has been conducted over the past several months to further define the performance ofHFC245fa as a foam blowing agent. The choice ofsurfactantis Table 20. Formulation used forsurfactantevaluation

Com B- component Varanol 370 '" Terol375 " Polycat 5 (31 Polycat41 0,

Water Surfactanl HFC-245fa A-component Mondur MR**~**.. !

Index 125 Temperature 60 0 F
fI)Dow Chemical
mOlOD Incorporate<!

(3)Air Products & Chemicals
(4) Bayer 70 30 0.7 0.5 1.0 2.5 24

129

Table 21. Surfactant vs. closedcell content 100



# - c 95 II 

# - C 0 0 

# " 90 II III 0 

### 0 85

### 'if80 88404 88409 88418 Surfactant 88433 88462



### a critical part ofoptimization ofthe k-factor ofa foam. In the transition from CFC-ll to HCFC-141b, it was discovered that the best foam performance in terms ofboth kfactor and physical properties was achieved with the use ofdifferent surfactants. Some very preliminary work has been completed using Goldschmidt surfactants studying the effect different surfactants have on the physical properties of foams produced with HFC-245fa. The initial work was done with the appliance formulation listed in Table 20. Thefoam was producedinL-molds and samples
were takento determinethe effect each surfactanthad on closed cell content, k-factor, flow and physical properties.

The tests suggest the use of Goldschmidt B8404 and B8462 produced foams with higher closed cell contents (Table 21) and lower k-factors 

### than those produced with other surfactants (Table 22). They also produced foams with better flowability (Table 23) and physical properties than other Goldschmidt surfactants. As 

### a result of this work, the use of Goldschmidt B8404 and B8462 were found to perform better than other Goldschmidt surfactants tested. Similarworkhas been completed on a series ofOSi surfactants. 1bdate OSi surfactantL-6900 appears tobethebestoftheOsisurfactantstested.Additional surfactant screening is currently in progress and will be reported in subsequentpapers.



### K-FACTORVS TIMEAND MEAN 

### TEMPERATURE

We have previously reported that foams produced with HFC-245fa age ata slowerrate thanfoams producedwith



### Bogdan, Williams, Logsdon, Parker / 

### 7' 0.16

0.155

0.15

0.145 LL
0.14

0.135

0.13

0.5 0.45 0.4 0.35 0.3 0.25 0.2 c 0.15 LL 0.1 0.05 0 Table 22. Surfactant vs. k-factor

B8404 B8409 88418 B8433 88460 B8462

Surfactant

Table 23. Surfactant vs. flowability

B8404 88409 B8418 B8433 B8451 B8460 B8462

Surfactant

HCFC-141b and CFC-11.12' Also, the results of the AHAM appliance trial demonstrated the importance of not only comparing foam k-factors but also comparing them at the temperature of the application. As a result a study of k-factor vs. mean temperature vs. time for a series of foams was run. The formulations used to prepare the foams is listed in Table 24. Foams were prepared with HFC-245fa, HCFC-141b, CFC-11SBA and cyclopentane. Both handmix and machine foams were made using the same formulation . The machine foams were prepared using a Martin Sweets low pressuremachine. Machine foams were not prepared for cyclopentane since the equipment available is not explosion proof.The foams were poured into panels. The density and reactivity for the foams produced are summarized in Table 25. Note the panels were formulated to a 2.2 lb. density to minimize shrinkage during aging of the cyclopentane foams.The k-factor of the foams were measured over time comparing the aging characteristics of the HFC-245fa and HCFC-141b foams (Figure 5). The HFC-245fa foams age at a slower rate than the HCFC-141b foams. This effect isfound at all temperatures tested. Figure 6 shows the kfactor vs. mean temperature for the HFC-245fa , HCFC141b and the cyclopentane foam at 56 days. The k-factorfor the HFC-245fa foams is significantly lower than the kfactor for the HCFC-141b and cyclopentane foams at all temperatures. The k-factor for the HFC-245fa foam isequivalent to the k-factor for foam produced with CFC11SBA at a mean temperature of 18 °F. This implies that in cold applications such as freezers or cryogenic tank insulation foams produced with HFC-245fa will give the Table 24. Formulations Component CFC-llSBA H



# T CFC-1416 cyclopentane95% HFC-245fa

- - -

__ w 0X717 47 Thanol R

_ __ 55 55 55 55 Plurocol975 '

7 45 45 45 45 Ter ostab B-8466'' 1.5 1.5 1.5 1.5 Polycat 77"' 1.5 1.5 - 1.5 1.5 Water 1.0 1.0 1.0 1.0 CFC-I I SBA 47

- HCFC-1416 40 Cyclo mane 95% 24 HFC-245fa 46

Lu rinate M20S'2' 132 132 132 132 Index 110 110 110 110 Eastman Chemical °iBASF t"Goldschmidt Chemical

Table 25. Reactivity and density data
Blowing Agent CFCIISBA HCFC1416 CP-95' HFC.

245fa CFCIISBA HCFC1416 CP-95'

Test Reactivity, sec Cream Time 18 18 22 20(F) 12 14.5 12 Gel Time 52 53 53 80 50 47 94 Tack Free Time 77 72 72 110 70 67 128
Density, lb. Free Rise 1 .39 1.37 1.43 1.38 1.35 1.35 1.35 Overall Panel -.^ - 2.19 2.21 .' ,. 2.19 2.22 2.24 2.22 2.22 Core 1.93 1.89 1.84 2 .04 1.96 1.87 2.02 ' Cyclopentane

- 95% purity (F)-Froth

insulation performance equal to or superior to CFC-11 foams.The response of thermal conductivity to mean temperature for these blowing agents is not surprising. Since HFC-245fa will maintain a higher vapor pressure in the foam cells at lower temperatures, the k-factor of the foams blown with HFC-245fa should improve compared to theHFC-141b'blown foams as the mean temperature decreases. The data tends to confirm that this is the case. Workwill continue in this area to more fully define the relationship between mean temperature, foam age, and thermal conductivity of HFC-245fa blown, foams.

SUMMARY A considerable body of data has been developed that demonstrates HFC-245fa is an excellent candidate as a "third generation" blowing agent for rigid polyurethane and polyisocyanurate foams. This liquid HFC has a low order of acute toxicity, is environmentally acceptable, and is stable in the presence of common foam raw materials and materials of construction. HFC-245fa has similardecomposition characteristics to HCFC-141b. Under certain conditions, it can decompose in polyisocyanurate foams to HFC-1234ze, which toxicity test results imply isnot highly toxic or mutagenic. The formation of HFC1234ze is both reaction time and catalyst dependent, a similar phenomenon to that found with HCFC-141b. From a processing perspective,, surfactants such as Goldschmidt B8404 and B8462 and OSi L-6900 improvethe quality of appliance foams when used with HFC245fa. Additional surfactants will be identified in the future that will enhance the performance of HFC-245fa.

8 / Bogdan, Williams, Logsdon, Parker



# .. S 0 

### t1.**~** .-' 0.16

0.155

0.15

0.145

0.14

0.135

0.13 Table 22. Surfactant VS. k-factor

B8404 B8409 B8418 88433 88460 88462 Surfactant

Table 23. Surfactant vs. flowability 0.5TWr----------------------------------- 0.45 +.-1---=----------111---=:---..,...-- 

## a 0.4 +t1---II---tIII---

....**-~**... -- .. --....-- 

### E 0.35 -r-.f---

__ - __---III_-

... --II--

___- .2. 0.3 +.-1--_.1--

.....1----11--

__--....--__--**~** 0.25 -r-.f----.--It--

... --tl--

.... --;II-- 

## i**O.2+t1---II---tII~-4I--** ... -- .. --....--**~** 0.15 +11----41--

.... ----1

... --11--

.....1--

... --**~** 0.1 +.-1--_.1--

.....1----11--

__--....--__-- 0.05 +111---

..... --;11----111---

.... ---;11---111--**O+-L_~JL-~--_~L-~JL--~---~L-_.** B8404 B8409 B8418 B8433 B8451 B8460 B8462 Surfactant



### HCFC-141b and CFC-ll.(2JAlso, the results ofthe AHAM appliance trial demonstrated the importance of not only comparing foam k-factors but also comparing them at the temperature ofthe application.

As 

### a result a study ofk-factor vs. mean temperature vs. time for a series offoams was run. The formulations used to prepare the foams is listed in Table 24. Foams were prepared with HFC-245fa, HCFC-141b, CFC-llSBA and cyclopentane. Both handmix and machine foams were made using the same formulation

. The machine foams
were prepared using a Martin Sweets low pressure machine. Machine foams were not prepared for cyclopentane since the equipment available is not explosion proof. The foams were poured into panels. The density and reactivityfor the foams produced are summarized in Table 25. Note the panels were formulated to a 2.2 lb. density to minimize shrinkage during aging of the cyclopentane foams.

The k-factor ofthe foams were measured overtime comparing the aging characteristics of the HFC-245fa and HCFC-141b foams (Figure 5). The HFC-245fa foams age at a slower rate than the HCFC-141b foams. This effect is found at all temperatures tested. Figure 6 shows the kfactor vs. mean temperature for the HFC-245fa
, HCFC141b and the cyclopentane foam at 56 days. The k-factor for the HFC-245fa foams is significantly lower thanthe kfactor for the HCFC-141b and cyclopentane foams at all temperatures. The k-factor for the HFC-245fa foam is equivalent to the k-factor for foam produced with CFCllSBA at a mean temperature of 18 OF. This implies that in cold applications such as freezers or cryogenic tank insulation foams produced with HFC-245fa Will give the



### 8 / Bogdan, Williams, Logsdon, Parker Table 24. Formulations Componcnl

Thanol R-470X '" Plurocol 975'"' Tergostab B-8466 " Polvcat 77 •• Water CFC-II SBA HCFC-14Ib CvcJQpentane 95'l< HFC-245fa

Luorinate M20Sf2\ Index
(l,Eastman Chemical n'BASF CFC·IlSBA

55 45 L5 L5 LO 47

132 110

0)Goldschmidt Chemical HCFC-141b Cyclopentane95'l<

w 55 55 45 45 L5 L5 L5 

### . L5 LO LO

40 24

132 132 110 110 HFC-245fa

55 45 L5 ' L5

LO

46**13~** 110

Table 25. Reactivityand density data
BlOWing Agent CFCIISBA Test Reactivity. sec Cream Time 18 Gel Tune 52 Tack Free Time 77
Density.lb Free Rise 139 Overall Panel " 2J9 Core L93

• Cyclopentane

-**95~** purity (F)-Froth HCFC141b

18 53 72

137 2,21

.

# ..
L89 CP-95* HFC- CFC- HCFC- CP-9S* 245fa IlSBA 141b

22 20(F) 12 145 12 53 80 50 47 94 72 110 70 67 128

L43 138 135 135 135 2.19 2.22 2.24 2.22 2.22 L84 2.04 L96 L87 2.02



### insulation performance equal to or superior to CFC-ll foams.

The response ofthermal conductivity to mean temperature for these blowing agents is not surprising. Since HFC-245fa will maintain a higher vapor pressure in the foam cells atlowertemperatures,thek-factor ofthefoams blown with HFC-245fa should improve compared to the HFC-141b'blown foams as the meantemperature decreases. The data tends to confirm that this is the case. Work will continue in this area to more fully define the relationship between mean temperature, foam age, and thermal conductivity ofHFC-245fa blown foams.



### SUMMARY

A considerable body of data has been developed that demonstrates HFC-245fa is an excellent candidate as a "third generation" blowing agent for rigid polyurethane and polyisocyanurate foams. This liquid .HFC has a low order ofacute toxicity, is environmentally acceptable, and is stable in the presence ofcommon foam raw materials and materials of construction. HFC-245fa has similar decomposition characteristics to HCFC-141b. Under certain conditions, it can decompose in polyisocyanurate foams to HFC-1234ze, which toxicity test results implyis not highly toxic or mutagenic. The formation of HFC1234ze is 

### both reaction time and catalyst dependent, a similarphenomenon to thatfound with HCFC-141b.

From a processing perspective,. surfactants such as Goldschmidt B8404 and B8462 and OSi L-6900 improve the quality of appliance foams when used with HFC245fa. Additional surfactants will be 

### identified in 

### the future that will enhance the performance ofHFC-245fa.

### HFC-245fa Temperature vs. k-Factor

0.17

0.13 ' r ---1 1 18.5 36.5 54.5 72.5 .90.5

Mean Temperature °F

-0 days

- 1 day -7 days - 28 days -•- 56 days Handmix Data Temperature vs. k-Factor at 56 Days

36.5 54 .5 . 72.5 Mean Temperature ° F

- CFC-11 SBA HCFC-141b - HFC-245fa

-- Cyclopentane

0.18

0.13 1 

### HCFC-141 b

Temperature vs. k-Factor

18.5 36 .5 54.5 72.5 90.5

Mean Temperature ° F
+-O days

-- I day 7 days -28 days -+- 56 days Figure 5. Aging curves of foams produced with HFC-245fa and HCFC-141 b

Additional foaming evaluations have further defined the performance of HFC-245fa as a foam blowing agent. Foam aging experiments have shown that the k-factors of foams produced with HFC-245fa age at a slower rate thanfoams produced with HCFC-141b. In most cases, the thermal conductivity of HFC-245fa blown foams is superior to those of HCFC-141b blown foams after several weeks of aging as unfaced core samples. It has also been shown that the k-factor of HFC-245fa foams improve relative to the k-factors of HCFC-141b blown foams as the mean temperature decreases. In areas of low temperature applications it has been found that foams produced with HFC-245fa perform equivalently to those produced with CFC-11. 0.17

90.5

Figure 6. k-Factor vs. mean temperature for foams produced with HFC-245fa, HCFC-141b, and cyclopentane

Although additional -work is necessary on HFC-245fa before it is fully defined as a foam blowing agent, we believe that this compound will become the blowing agentof choice for the future. We are committed to the development and commercialization of HFC-245fa as the "third generation" blowing agent for the polyurethane and poly-. isocyanurate foam insulation industry.

ACKNOWLEDGMENTS The authors wish to thank Mr. K. Cook, Dr. H. Magid, Mr. D. F. Orlowski, Ms. C. Beck, Mr. D. Konopa, Mr. L.Bement and many others at AlliedSignal for their contributions to this paper. We also wish to thank Goldschmidt, Osi, Demilec and AHAM for providing valuable data for this paper.



### REFERENCES 1. G. M. Knopeck, R. C. Parker, R. G. Richard, M. C. Bogdan, "Update on the development of HFC-245fa as a Liquid HFC Blowing Agent" Proceedings of The Polyurethanes World Congress 1995 p.2 2. G. M. Knopeck, R. C. Parker, R. G. Richard and I. R. Shankland, "Status Report on the Development of a Liquid HFC Blowing Agent" Proceedings of The Polyurethanes World Congress 1994 p. 115 3. T. W. Bodnar, J. E. Dewhurst, J. J. Koch, T. R. Demmin, R. E. Eibeck and R. C. Parker, "Minimization of HCFC-141b Decomposition in Rigid Polyisocyanurate Foams" Proceedings of the Polyurethanes 1992 Conference p. 374 4. M. Bogdan, D. Orlowski, J. Bennington, J. Welch, "A Method for the Determination of Cell Gas Content in Polyurethane Foams" Proceedings of the Polyurethanes 1995 Conference p. 34

Bogdan
, Williams, Logsdon, Parker 19 

# .. 0 

# - u III u.



# . .:II:



# .. HFC-24Sfa Temperature vs. k-Factor 0.17,-------------:z----

0.16

0.15

0.14

-

0.13 18.5 36.5 54.5 72.5 .90.5 Mean Temperature of

-0days --1 day --7 days -28days

-- 56days



### HCFC-141b Temperature vs. k-Factor 0.18,-----------------

0.17 -..::------------..,.,...::;...---- 

### S 0.16 r'"-c::::::------"==-

..... 

## ==-------::;:.".c:..----
u

## ~**I_--------~::====::==~-------------** .:.::: 0.15-t

0.14**~:=-====::::::::::::::::--"Ap~---**

## ~ 

# --=== 0.13

### -t-~~::::=:=;::::=:.-.----r__----, 18.5 36.5 54.5 72.5 90.5 Mean Temperature ° F

--0days --1 day --7 days -28days

-- 56 days Figure 5. Aging curves of foams produced with HFC-24Sfa and HCFC-141b



### Additional foaming evaluations have further defined the performance of HFC-245fa as a foam blowing agent. Foam aging experiments have shown that the k-factors of foams produced with HFC-245fa age at a slowerrate than foams produced with HCFC-141b. In most cases, the thermal conductivity ofHFC-245fa blown foams is superiorto those of HCFC-141b blown foams after several weeks ofaging as unfaced core samples. It 

### has also been shown that the k-factor of HFC-245fa foams improve relative to the k-factors ofHCFC-141b blown foams as the mean temperature decreases. In areas of low temperature applications it has been found that foams produced with HFC-245fa perform equivalently to those produced with CFC-ll. 

# .. 0


# - u III u.



# . .:II: Handmix Data Temperature va. k-Factorat56 Days

0.17

# t==== 

# ---**--------~-------** 0

..16

0.15

0.14

0.13 18.5 36.5 54.5 72.5 90.5 Mean Temperature ° F

-CFC-11 SBA --HCFC-141b -HFC-245fa

- Cyclopentane Figure 6. k-FactorVS. mean temperature for foams produced with HFC-245fa, HCFC-141b, andcyclopentane



### Although additional -Work is necessary on HFC-245fa before it is fully defined as a foam blowing agent, we believe that this compound will become theblowing agent ofchoice for the future. We are committed to the development and commercialization ofHFC-245fa as the "third generation" blowing agent for the polyurethane and polyisocyanurate foam insulation industry.



### ACKNOWLEDGMENTS

The authors wish to thank Mr. 

### K. Cook, Dr. H. Magid, Mr. D. F. Orlowski, Ms. C. Beck, Mr. D. Konopa, Mr. L. 

### Bement and many others atAlliedSignal for their contributions to this paper. We also wish tothank Goldschmidt, Osi, Demilec and AHAM for providing valuable data for this paper.



### REFERENCES 1. G. M. Knopeck, 

### R. C. Parker, 

### R. G. Richard, M. C. Bogdan, "Update on the development ofHFC-245fa as a Liquid HFC Blowing Agent" 

### Proceedings of The Polyurethanes World Congress 1995p.2 2. G. M. Knopeck, 

### R. C. Parker, R. 

### G. Richard and 1. 

### R. Shankland, "Status Report on the Development of a Liquid HFC Blowing Agent" 

### Proceedings ofThe Polyurethanes World Congress 1994 p. 

### 115 3. T. W. 

### Bodnar, 

### J. E. Dewhurst, 

### J. J. Koch, T. R. 

### Demmin, R. 

### E. Eibeck andR: C. Parker, "Minimization of HCFC-141b Decomposition in Rigid Polyisocyanurate Foams" 

### Proceedings of the Polyurethanes 1992 Conference p. 

### 374 4. M. Bogdan, D. Orlowski, 

### J. Bennington, 

### J. Welch, "A Method for the Determination ofCell Gas Content in Polyurethane Foams" 

### Proceedings of the Polyurethanes 1995 

### Conference p. 34



### Bogdan,.Williams, Logsdon, Parker I 

### 9

### r I3IOGR,APHIES D. J. Williams Dave Williams holds a B.S. degree in Chemistry from The University of New Haven, New Haven, CT, USA. From 1975 to 1994, heworked as a Research and Development Chemist and Technical Service Representative for the Upjohn Company and later The Dow Chemical Company in a wide variety of rigid polyurethane and polystyrene foam application
areas. Dave joined AlliedSignal in 1994 and is currently the manager of the Blowing Agent Technical Service and Development Group as well as the co-leader of the teamresponsible for the commercialization of HFC-245fa at AlliedSignal's Buffalo Research Laboratory. In these capacities, he responsible for technical' service and product development of Allied-Signal's line of CFC, HCFC, and HFC foam blowing agents.
M.C. Bogdan Mary Bogdan holds a B.S. degree in Chemistry and an M.B.A. from Canisius College. Since joining AlliedSignal in 1989, she has beeninvolved in a variety of fluorocarbon and fluorine specialty research programs. She has been a Group Leader in the Analytical Services Group. Currently, Mrs. Bogdan is a Senior ResearchChemist in the Genetron® Products Technical Service andApplications group at AlliedSignal's Buffalo Research Laboratory. She has global responsibility forconstruction and systems applications. P. B. Logsdon Peter B. Logsdon received a B. S. degree in Chemistry from SUNY Brockport in 1986 and a M. S. in Physical - Chemistry from the University at Buffalo in 1989. Since joining AlliedSignal in 1989,he has been involved in the development of CFC replacements for solvent, refrigerant, sterilant gas and blowing agent applications.Mr. Logsdon is currently a member of the Genetron® BlowingAgent Technical Service and Applications Group and has global responsibility for appliance, ex= truded foam and integral skin foam applications.

R.C. Parker Robert C. Parker received a B.A. in chemistry from Lake Forest College in 1963 and a M.S. degree in organic chemistry from West Virginia University in 1967. He joined AlliedSignal in 1989 and iscurrently working in the Genetron® Products Technical Serviceand Applications group at AlliedSignal's Buffalo Research Laboratory. He is a member of the team responsible for the development and commercialization of liquid HFC foam blowing agents. "

10 / Bogdan, Williams, Logsdon, Parker 

### '/ BIOGRAPHIES

fr-(! 

### D.J. Williams 

### Dave Williams holds a B.S. degree in Chemistry from The University of New Haven, New Haven CT USA. From 1975 to 1994,

### h~ worked as a Research and Development Chemist and Technical Service Representative for the Upjohn Company and later The Dow Chemical Company in a wide variety of rigid polyurethane and polystyrene foam application
areas. DavejoinedAlliedSignal in 1994 and is currentlythe manager of the Blowing Agent Technical Service and Development Group
aswell as theco-leader ofthe team responsible for the commercialization ofHFC-245fa atAlliedSignal's Buffalo Research Laboratory. In these capacities, heresponsible for technical se:rvice and product development ofAllied-Signal's-line of CFC, HCFC, and HFC foam blowing agents. 

### M.C.Bogdan Mary Bogdan holds a B.S. degree in Chemistry and an M.B.A. from Canisius College. Since joining AlliedSignal in 1989, she has been involved in a variety of fluorocarbon and fluorine specialty research programs. She has been a Group Leader in the Analytical Services Group. Currently, Mrs. Bogdan is a Senior Research Chemist in the Genetron® Products Technical Service and Applications group at AlliedSignal's Buffalo Research Laboratory. She has global responsibility for construction and systems applications.

10IBogdan, Williams, Logsdon, Parker 

# ! P. B. Logsdon 

## I Peter B. Logsdon received a B. S.
: degree in Chemistry from SUNY

Brockport in 1986 and a M. S. in Physical. Chemistry from the University at Buffalo in 1989. SincejoiningAlliedSignal in 1989, he has been involved iii the development of CFC replacements for solvent, refrigerant, sterilant gas and blowing agent applications. Mr. Logsdon is currently a member of the Genetron® Blowing AgentTechnical Service andApplications Group and has global responsibility for appliance, exc 

### truded foam and integral skin

. foam applications.


### R.C. Parker Robert C. Parker received a B.A. in chemistry from Lake Forest College in 1963 and a M.S. degree in organic chemistry from West Virginia University in 1967. He joined AlliedSignal in 1989 and is eurrently working in the Genetron® Products Technical Service and Applications group at Allied· Signal's Buffalo Research Laboratory. He is a member ofthe team responsible for the development and commercialization of liquid HFC foam blowing agents

..