U. S. Environmental Protection Agency June 20, 2003 Draft Agenda Fluoropolymer Technical ECA Workgroup Meeting Monday, June 23, 2003 9: 00 12: 00 PM Mission Statement: The Fluoropolymer Workgroup will develop ECA proposal( s) for data needs identified in items 2, 7, 8, 9 and 11 of Table II in the EPA Preliminary Framework document, specifically addressing: ( a) the physical/ chemical ( p chem) properties of the fluoropolymers; ( b) the presence of PFOA emitted from fluoropolymer treated products and articles as they age during use for those products and articles not included in the Letter of Intent ( LOI) commitments; ( c) determining the incineration byproducts of fluoropolymers and fluoropolymer treated articles and determining the p chem, fate, and transport properties of those byproducts; and ( d) product stewardship information.

Meeting Objective: Scoping meeting to: 1. Identify, with respect to each of the data needs enumerated above in the EPA Preliminary Framework, what specific portions of the work are included in the LOI, to allow all workgroup participants to understand fully what is included, how many and what chemicals/ types of chemicals are covered, what tests will be conducted, what protocols will be used, when information will be reported, etc. 2. Identify and discuss activities within the EPA Preliminary Framework beyond the scope of the LOI which may be appropriate for consideration in the ECA process; 3. Identify workgroup next steps and assignments Workgroup Participants: 3M; Bennett & Williams; CPSC; EPA; EWG; FMG Order of Meeting:

° Introductions: Chair, Phil Oshida, Director, Chemical Control Division, U. S. EPA EPA Technical Lead: John Blouin, Economics, Exposure & Technology Division ° Presentation on scope of LOI commitments ( OPPT 2003 0012 0012) by industry ° Discussion of activities beyond the LOI commitments for consideration by ECA process ° Identification of workgroup next steps; determination of workgroup assignments for workgroup and plenary meetings on July 9 and 10, 2003 PFOA ECA Fluoropolymer Technical Workgroup Meeting June 23, 2003 NAME ORGANIZATION TELEPHONE # E MAIL ADDRESS 1~ O6etrL iF1~ tPJ ~ v, O ~ L,. 14~(/ Øc~ I, JcU\ h~ Et ~ 1t1o_~ Ivj_ z~ 11 ~ 2I3~ f~(~? L4t4.~ 6e~ Qfc*# 1et ~~, 4O( ~

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D ~° ü Fluoropolymer Technical ECA Workshop Agenda ° Product Stewardship ° Physical/ Chemical properties of Fluoropolymers ° Articles of Commerce Testing ° Incineration FMG  Product Stewardship June 23rd, 2003 EPA ECA Framework Objective Improved understanding on industry's product stewardship efforts with respect to the products and issues for which PFOA is a concern FMG LOI Commitment ° The fluoropolymer manufacturers have, and will continue to follow principles of product stewardship similar to those described by ACC or SOCMA Responsible Care ® programs.

° The FMG is committed under the LOI to providing appropriate product stewardship information to fluoropolymer processors. FMG  Product Stewardship ( PS)

Efforts ° Leadership, accountability and performance measurements and resource commitment:

  Each company maintains written policies developed and approved by senior management around product stewardship and incorporates PS in business planning and individual performance planning.

  Companies commit resources to industry efforts to provide best collective knowledge of product health and safety information. Information is published in industry documents. FMG  Product Stewardship ( PS)

Efforts ° Safety, Health, and Environmental information:

  Industry members individually and collectively work through trade organizations e. g SPI/ APME to maintain and share latest SHE information   Examples:

° MSDS sheets for all products sold ° Guide for Safe Handling of Fluoropolymer Resins ° Guide for Safe Handling of Fluoropolymer Dispersions ° Technical literature   LOI commitment ° share technology for recycle and destroy or use ° emission reduction program ° update safe handling guide FMG  Product Stewardship ( PS)

Efforts ° Product risk characterization, management,

design and improvement.

  Industry works through APME's Toxicology group to fund relevant toxicology and environmental fate research to better understanding.

  LOI commitment ° 10 studies funded for completion in 2003 FMG  Product Stewardship ( PS)

Efforts ° Employee education and product use including contract manufacturers, and distributors.

  FMG companies have and continue to be committed to the education of their employees, contract manufacturers and distributors with training through product literature and safe handling guides   LOI commitment: share specific safety, health and environmental compliance programs with EPA. FMG  Product Stewardship ( PS)

Efforts ° Customers and direct receivers of products   Information provided through individual company MSDS, product literature, processing technical guides.

  Industry documents e. g. Safe Handling Guides   Training at customer sites and trade association meetings ° PFOA reviews at SPI Fluoropolymer Division semi annual meetings held Oct. 2000, March 2001, October 2001, March 2002, October 2002, and April 2003   Technical support to processors to enable to meet statutory obligations. FMG  Product Stewardship ( PS)

Efforts ° Customers and direct receivers of products ( cont'd)

  LOI commitments:

° Develop representative material balance for fate of PFOA at fluoropolymer dispersion users' sites.

° Develop representative articles of commerce testing ° Define appropriate product stewardship elements to address findings.

° Continue to provide updated information as developed to maintain occupational and safety standards current. Product Stewardship Summary ° Industry has had comprehensive PS programs over the years following accepted principles ° LOI commitment:

  Fund additional toxicology and fate studies   Update information materials with new information   Continue to conduct training and offer technical support to processors   Fund study to understand material fate at users of dispersion fluoropolymers.

  Share technology to reduce environmental emissions Product Stewardship Summary ° FMG believes that Product Stewardship needs are included in LOI ° FMG member companies are willing to provide additional information on their programs as needed Physical/ Chemical Properties ° Document prepared to address Item 2 of the framework document ( Document also addresses item 3)

° Recommendation: interested parties review document and discuss any additional needs at the July 9 technical meeting. Articles of Commerce Testing LOI Summary ° Intent of study: evaluate the potential for articles of commerce to contribute to APFO exposure ° Commits to analysis for APFO in articles made with:

  Dry fluoropolymer resins   Liquid dispersions ° Articles selected based on:

  Widespread consumer use   Sample of industrial and commercial products Articles of Commerce Testing ° Selection Criteria   Consumer applications  applications where the general public may routinely comes in contact with articles containing a fluoropolymer   Industrial applications  applications that are used in an industrial or commercial setting   High heat processing  applications where the article during manufacture receives thermal exposure ( time and temperature) above where APFO is expected to be driven off or destroyed   Low heat processing  applications where the article during manufacture may not receive such thermal exposure Articles of Commerce Testing ° Prioritization criteria based on potential exposure routes   Consumer applications   Low heat applications   Higher Volume industrial applications ° Test Protocol   New articles ° FDA Test 21 CFR 175.300 ° Extraction with appropriate simulated food solvents ° Targeted completion by end of 2003   Aged articles ° FDA Test  Guidance for Industry, dated April, 2002 ° Extraction with appropriate solvents for 240 hours Articles of Commerce Testing ° Next Steps   New Articles ° FMG will review articles for testing covered in the LOI on July 9 ° Develop and Finalize study plan ° Validate analytical methods ° Identify 3rd parties for testing ° Complete timeline   Aged Articles ° Based on results above, select appropriate articles for testing Incineration of Fluoropolymers ° Intent: determine if incineration results in emissions of PFOA   Fluoropolymers   Fluoropolymer containing articles ° Protocol   Model incineration using Univ of Dayton lab scale thermal degradation test ° Municipal and Hazardous Waste incineration Incineration of Fluoropolymers ° Choose representative fluoropolymers and articles ° Adapt existing protocol to fluoropolymers,

  Use 3M study as basis   Set up detection system capable of capturing and quantifying PFOA in exhaust stream   Review protocol with EPA prior to starting test BASIC FLUOROPOLYMER DATA ( 23 June 2003)

Fluoropolymers Manufacturing Group ( FMG) Society of the Plastics Industry, Inc. ( SPI) 1801 KStreetNW Washington, D. C.

Table of Contents Introduction Item 2. P chem properties to inform fate testing Item 2.1 Polytetrafluoroethylene, PTFE Item 2.1.1 Polymerization Item 2.1.2 Properties Item <IP_ADDRESS> Molecular Structure Item <IP_ADDRESS> Molecular Weight and Crystallinity Item <IP_ADDRESS> Transitions Item <IP_ADDRESS> Chemical Resistance <IP_ADDRESS> Oxygen Compatibility ofPTFE Item 2.2 Perfluoroalkoxy Polymer, PFA Item 2.1.1 Polymerization Item 2.1.2 Properties Item <IP_ADDRESS> Molecular Structure liem <IP_ADDRESS> Molecular Weight and Crystallinity Item <IP_ADDRESS> Transitions Item <IP_ADDRESS> Chemical Resistance Item 2.3 Perfluorinated Ethylene Propylene Copolymer, FEP Item 2.1.1 Polymerization Item 2.1.2 Properties Item <IP_ADDRESS> Molecular Structure Item <IP_ADDRESS> Molecular Weight and Crystallinity Item <IP_ADDRESS> Transitions Item <IP_ADDRESS> Chemical Resistance Item 2.4 Optical Spectral Properties and Weathering Resistance of Fluoropolymers Item 2.5 Effect of Ozone on Fluoropolymers Item 3. Elucidation of degradation pathways and identification of degradation products  2 FLUOROPOLYMER DATA NEEDS Introduction Commercial fluoropolymers based on TFE include homopolymers and copolymers. Homopolymers contain 99% or more by weight TFE and 1% or less by weight of another monomer according to the convention by American Societyfor Testing Materials ( ASTM). The comonomers may or may not be fully fluorinated. Commercially significant examples of the minor comonomers ( also called modifiers) include perfluoromethyl vinyl ether ( PMVE), perfluoroethyl vinyl ether ( PEVE), perfluoropropyl vinyl ether ( PPVE), hexafluoropropylene ( HFP), chlorotrifluoroethylene ( CTFE) and perfluorobutyl ethylene ( PFBE). Ofthese, CTFE and PFBE are not perfluorinated.

Copolymers of TFE ( according to the ASTM definition) contain 1% or more by weight of one or more comonomers. Commercially significant examples of these comonomers include PMVE, PEVE, PPVE, HFP and combinations thereof.

In this paper, ASTM definition of homopolymer and copolymer is observed for clarity. Furthermore, separate discussion/ data are presented for homopolymer and copolymers where ease of understanding and clarity of discussion are enhanced by such division. It is noteworthy to realize that generally all perfluoropolymers are available in pellet, fine powder and dispersion forms.

Item 2. P chem properties to inform fate testing " P chem properties" is the abbreviation for the physico chemical properties of fluoropolymers. The intent of this Item is to explore physical chemical properties that provide information (" inform") about the destiny (" fate") of fluoropolymers after they have been produced, be it in application or other manners ofpresence.

Item 2.1 Polytetrafluoroethylene, PTFE [ CAS number 9002 84 0]

Item 2.1.1 Polymerization This plastic is a perfluorinated straight chain polymer with very high molecular weight. It is produced by free radical polymerization mechanism in an aqueous media via addition polymerization of tetrafluoroethylene ( CF2= CF2, molecular weight 100.02, CAS number 116 14 3). Contrary to condensation polymerization, no molecule has to be removed to allow the addition polymerization to occur. The initiator for the polymerization is usually awater soluble peroxide such as ammonium persulfate or disuccinic peroxide. Aredox catalyst is used when low temperature polymerization is desired. PTFE can be produced by suspension ( orslurry) polymerization in the absence of a surfactant to obtain granular resins or in the presence of a perfluorinated surfactant ( emulsion polymerization) to produce fine powder and dispersion products.

There also low molecular weight grades of PTFE, called micropowders, micronized powder andfluoroadditives, that are produced by either direct polymerization or radiochemical/ thermal degradation of high molecular PTFE. These powders are usually used as a minor ingredient to impart fluoropolymer like properties to a host system, such as thermoplastics or printing inks.

Basic Fluoropolymer Data ( 23 June 2003).  3 Item 2.1.2 Properties PTFE has unique properties such as chemical inertness, heat resistance ( both high and low), electrical insulation properties, low coefficient of friction and non stick property over a wide temperature range. It has a density in the range of 2.1 2.3 g/ cm3 and melt viscosity in the range of 1 10 GPa. s [ 1]. PTFE melt does not flow because of its high molecular weight, thus requiring non conventional fabrication techniques similar to those employed for metal powder ( granular PTFE), ceramic paste ( fine powder PTFE) and latex ( dispersion PTFE) processing. Three ASTM methods and ISO standards govern the classification of various forms of PTFE. These methods include ASTM D4894 98 ( granular), ASTM D4895 ( fine powder), ASTM D4441 98 ( dispersion) and ASTM D5675 98 ( micropowders, except dispersions D4441 98). ISO Standards 12086 1 and 12086 2 specify all forms of PTFE.

Item <IP_ADDRESS> Molecular Structure Figure 2.1 shows a schematic of a segment of a PTFE molecule, which is, in reality, appears as a helix with 13 carbons atoms required for a 180 ° turn at temperature < 19 ° C. At temperatures > 19 ° C, 15 carbon atoms are necessary for a 180 ° turn. Recent Atomic Force Microscopy research at NASA has actually revealed the helical structure of PTFE ( Figure 2.2).

r F F F F Figure 2.1 A Segment ofPolytetrafluoroethylene Molecule The backbone of the molecule is formed of carbon carbon bonds, where each carbon is bonded to two fluorine atoms. Both are extremely strong bonds ( C C, 607 kJ/ mole and C F, 552 kJ/ mole.). The basic properties of PTFE stem from these two very strong chemical bonds. The size of the fluorine atom allows the formation of a uniform and continuous covering around the carbon carbon bonds and protects them from attack, thus imparting chemical resistance and stability to the molecule. PTFE is rated for continuous use up to 260 ° C. PTFE does not dissolve in any common organic or inorganic solvent. In fact, no common commercial chemical is known to chemically attack PTFE. The fluorine sheath is also responsible for the low surface energy ( 18 dynes/ cm) and low coefficient of friction ( 0.05 0.8, static) of PTFE. Another attribute of the uniform fluorine sheath is the electrical inertness ( or non polarity) of the PTFE molecule. Electrical fields impart only slight polarization in this molecule, so volume and surface resistivity are high.

Basic Fluoropolymer Data ( 23 June 2003)  4

Depth Figure 2.2 Fourier filtering Mode of Image Obtained by Atomic Force Microscopy the bright white spots show individual fluorine atoms along the PTFE Chain [ 2]

Item <IP_ADDRESS> Molecular Weight and Crystallinity Apractical consequence of chemical inertness of PTFE is that primary methods such as Osmotic pressure and intrinsic viscosity or secondary methods such as gel permeation chromatography and fractional precipitation can not measure its molecular weight. Instead an indirect indication is used to judge molecular weight. Standard specific gravity ( SSG) consists of ( perASTMMethods D4894 or D4895) measurement of the specific gravity of a chip prepared according to standardized compression molding, heating ( sintering) and cooling rate cycles. The underlying principle is that lower molecular weight PTFE crystallizes more extensively, thus yielding higher SSG values [ 3]. The operating assumption is an absence of voids in the PTFE chip, although there are methods to correct for the voids [ 4].

SSG has been correlated with molecular weight in a study in which the end groups were marked by using an initiator containing a radioactive sulfur [ 5]. Commercial polymers were found to have number average molecular weights in the range of one to 10 million. A correlation ( Eq. 2.1) has been developed [ 6] to calculate a number average molecular weight using measured SSG values. Table 2.1 shows examples ofM~ values calculated from equation M~ O. 597[ log 0.157 ] x106 ( 2.1) 2.306   SSG A Basic Fluoropolymer Data ( 23 June 2003)  5

Table 2.1 Calculated Values ofMolecular Weight ( Eq. 2.1) SSG M~ x1116 2.16 18.9 2.20 9.6 2.25 3.5 2.30 0.4 Melting and crystallization of PTFE has been studied by Differential Scanning Calorimetry ( DSC) and a correlation has been found between the heat of crystallization and the number average molecular weight [ 7]. This correlation ( Eq. 2.2) is independent of cooling rate in the range of 4 32 ° C/ mm. In this equation DeltaH~ is the heat of crystallization in J/ g. For example a heat of crystallization of 26 J/ g yields aM~ of 1 .7x1 06.

  10   5.16 M~= 2.1x10( Deltaj j~) ( 2.2)

PTFE that has not been previously melted has a ciystallinity of 92 98%, indicating a linear and non branched molecular structure. Upon reaching 342 ° C, it melts changing from a chalky white color into a transparent amorphous gel. The second melting point of PTFE is 327 ° Cbecause it never re crystallizes to the same extent as prior to its first melting. Melting point of PTFE increases with pressure.

It is difficult to determine the molecular weight distribution of PTFE because of absence ofMW measurement. An indication of the MW distribution is the width of the DSC thermogram at half the height atthe peak melt point. Basically, the wider the thermogram, the broader the MW distribution ( line segment AB in Figure 2.3).

Heat Flow A B TemDerature Figure 2.3 Schematic ofDSC Thermogram Basic Fluoropolymer Data ( 23 June 2003)  6

Item <IP_ADDRESS> Transitions Anumber of first and second order transitions have been reported for PTFE as summarized in Table 2.2. Those transitions that are close to room temperature are of practical interest because of their impact on processing of the material. Below 19 ° Cthe crystalline system of PTFE is anearly perfect triclinic. Above 19 ° C, the unit cell changes to hexagonal. In the range of 19   30 ° C, the chain segments become increasing disorderly and the preferred crystallographic direction disappears. Between 19 ° Cand 3 0 ° C, there is a large expansion in the specific volume of PTFE approaching 1.8% [ 8] which must be considered in measuring the dimensions of articles made from this plastics.

Item <IP_ADDRESS> Chemical Resistance Polytetrafluoroethylene is by far the most chemically resistant polymer among thermoplastics. Few substances chemically interact with PTFE. The exceptions among those commercially encountered include molten alkali metals, gaseous fluorine at high temperatures and pressures, and few organic halogenated compounds such as chlorine trifluo. ride( CJF3 ) and oxygen difluoride ( OF2). The inertness of PTFE arises from its molecular structure. Afew other chemicals have been reported to attack PTFE at or near its upper service temperature ( 260 ° C). PTFE reacts with 80% sodium or potassium hydroxide. It also reacts with some strong Lewis bases including metal hydrides such as boranes Table 2.2 Transitions of Polytetrafluoroethylene [ 9]

31J St 1 Order ,

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Crystal Disorder `) fl I } rder Crystalline ~ LX) 2uid Order Amorphous On set ot rotaticoial motion around C C bond  31) Order Amorphous 1 30 2'~( irder Amorphous ( B2H6), aluminum chloride, ammonia, and some amines ( R NH2) and imines ( R= NH). Slow oxidative attack may take place by 70% nitric acid at 250 ° Cunder pressure. It is important to test the effect of these reagents on PTFE under the specific application temperature to determine the material limitations.

Tables 2.3 through 2.6 show actual results of chemical compatibility testing for a large number of chemicals from various classes of compounds. Based on the chemical resistance of PTFE, one can conclude that there is no possibility of hydrolysis of PTFE. Water alone has no effect on PTFE or any other perfluoropolymer.

Other properties of PTFE can be found in Table 2.7. 19 1 Ot icr crystalline Anrular Displacement Basic Fluoropolymer Data ( 23 June 2003) 7

Table 2.3 Chemical Resistance of PTFE to Common Solvents [ 10]

20 SI) 70 0,3 0,4 0 Table 2.4 Chemical Compatibility ofPTFE with Halogenated Solvents [ 11]

chemw~ i1 Ch. lorofomi Elfect on PTFE Saniple Wets, insoluble at boi: Ling point Ethylene Bromide 0.3% weight' gain after 24 hr. at l00~ C Fhioiinatnd Hydrocarbons Wets, s~ veflingoccurs in bailing solvent Fluoro naphthàlene iusokthle at boiling çcilnt, same swelling FlLloiomtmbenzene Insolub: le at boiling ~ xiaL some sweiing Pen tachIorobenzamide insoluble PerfiL: Ioioxyleue insoluble at bailing point, slight sweilling Tetmbron'ioethane hisoluble at boiling point Tetmc1iioro~ h. yieiie Wets, sonic s~ eiiingafter 2 hr at I20~ C Trirhioroacetic Acid hisollubie at bailing point Trickloroethvlene : L1iSOlUbiB at boilling point after 1 hr. Acetone 12 ma 12 me. 2 wk,

Beniene 75 96 hr 05 100 $ hr 200 S hr 1.0 Carbon Tetrachloride 25 i2mo, 0.6 50 12 mo. 1.6 70 2 wk. 1.9 100 $ hr 2.5 200 8 hr 3.7 Ethanol ( 95W)

. 25 121110. 0 50 12 ma ( 1 ~ 70 2 wk, 0 100 Shr 0,1 200 S hr 0.3 Ethyl A~ etate 25 l2ino, 0,5 50 121110, 0.7 70 2 wk. 0,7 Tolnene 25 121110, 0.3 50 12 mc. 0.6 70 2 wk. 0.6 Basic Fluoropolymer Data ( 23 June 2003)  8

Table 2.5 Chemical Compatibility of PTFE with Common Acids [ 12]

Reagent E'wosure Eiposure Thee %~~ uI Gain, % Temperature, C Hydrochloric Acid lU% 25 12 . i. no. 0 10% 50 12 mo 0 llJ% 70 12 ma U 20% 100 Shr U 209~, 200 Shr U Nitric Arid 10% 10% 25 12 mc. 70 l2mo. U 0.1 Sulfuric Acid 30% 30% 30% 30% 25 12 ma 70 l2mo, 100 S hr 2: 00 . Sin 0 0 0 ( LI Sodium HydroxIde 10% 10% 50% 50% 25 l2mo, 70 12. ina 100 Shr 200 Sin 0 0.1 0 0 Ainmoniurn Hydroxide 10% 10% 25 12am. 70 12 mo. 0 0.1 <IP_ADDRESS> Oxygen Compatibility ofPTFE Oxygen is singled out due to its propensity to facilitate auto ignition of organic material including plastics. Fluoropolymers are extensively used for oxygen services because of their low flammability. Oxygen does not interact with polytetrafluoroethylene under most circumstances.

Limiting oxygen index ( LOI) of PTFE is greater than 95% under ambient conditions. This means that PTFE does not burn without an ignition source in an atmosphere containing less than 95% oxygen. LOI is not a complete predictor of all practical conditions in which oxygen and PTFE may interact. Anumber of considerations apply.

Basic Fluoropolymer Data( 23 June 2003)  9 Table 2.6 Chemical Compatibility of PTFE with Common Acids [ 13]

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Table 2.7 Various Properties of Fluoropolymers [ 14,15,16]

Property PTFE FEP ETFE PFA Specific Gravity 2.15 2.15 1.70 2.15 Melting Point ( 2nd), ° C 327 260 270 310 Tensile Strength, MPa 20 20 40 28 Elongation, % 300 300 200 300 Flexural Modulus, MPa 560 650 1,100 650 Temperature Rating, ° C 260 200 150 260 Dielectric Constant 2.1 2.1 2.6 2.1 Coefficient ofFriction 0.1 0.2 0.4 0.2 Cut Through, kg 4.5 4.5 18 4.5 Chemical Resistance Excellent Excellent Very good Excellent Item 2.2 Perfluoroalkoxy Polymer, PFA [ CAS number 26655 00 5]

Item 2.2.1 Polymerization PFA is a copolymer of TFE and aperfluoroalkyl vinyl ether such as perfluoropropyl vinyl etherPPVE ( CF2CF O C3F7, molecularweight 266, CAS number 1623 05 8)), which can be produced, in an aqueous and non aqueous media. Terpolymers of this class contain other monomers such as hexafluoropropylene HFP ( CF2CF CF3, molecular weight 150.02, CAS number 116 15 4) Commercially, it is polymerized by free radical polymerization mechanism usually in an aqueous media via addition polymerization of TFE and perfluoropropyl vinyl ether. The initiator for the polymerization is usually a water soluble peroxide such as ammonium persulfate. In general, the polymerization regime resembles that used to produce PTFE by emulsion polymerization.

Item 2.2.2 Properties ofPFA PFA polymers are fully fluorinated and melt processible. They have chemical resistance and thermal stability comparable to polytetrafluoroethylerre ( PTFE). Meltviscosity of PFA is more than one million times lower than PTFE (< 10~ Pa. s). Specific gravity of perfluoroalkoxy resins is in the range of 2.12 2.17. Perfluoroalkoxy polymers melt and flow and can be processed by typical thermoplastic techniques such as extrusion, injection molding and rotational molding. PFA resins are specified by ASTM Method D3307, which also provides procedures or references to other ASTM methods for the measurement of resin properties. Figure 2.4 illustrates a segment of PFA molecule.

Item <IP_ADDRESS> Molecular Structure Perfluoroalkoxy polymers have a similar structure to PTFE except that randomly after every few TFE monomer units a comonomer ( e. g., PPVE) appears in the molecule, as shown in the Figure 2.4. For example for a copolymer containing 3.5% by weight of PPVE, the ratio of Basic Fluoropolymer Data ( 23 June 2003)   11   TFE to PPVE is about 99 to 1. Of course this ratio is an average value and the actual number of TFE units occurring between consecutive PPVE groups may be more or less than 99. The comonomer pendent groups reduce the extent of crystallization as well as the size of individual crystallites.

liem <IP_ADDRESS> Molecular Weight and Crystaiinity Crystallinity and specific gravity of PFA parts decrease when the cooling rate of the molten polymer is increased. The lowest crystallinity obtained by quenching molten PFA in ice was 48% ( specific gravity 2.123).

  c   c   C   c   c   c   I 1 I I I I F F F F F Figure 2.4 A Segment of Perfluoroalkoxy Polymer ( PFA) Molecule ( Rf = C3F7, C2F5 or CF3) Similar to PTFE, molecular weight of PFA can not be measured by conventional techniques. An indirect factor called meltflow rate ( MFR) also called meltflow index ( MFI) is used which is the amount of polymer melt that would flow through a capillary rheometer at a given temperature under a defined load ( Figure 2.5). For PFA and FEP, MFR is defined as the Load (~ M+ Astm=~ D. ff/ o)

  Piston Theimcumter ( D= a4742n~ i)

0rPRF (~ o. 1' c,

,. Bairel u' ( D= 555O4mr~

Taiiper~ ure ContrxI ( ± 02C)

) N ( D~ 2Ll9~ rTnl L~ 8OOOrmj Figure 2.5 Schematic Diagram ofMFR ( MFI) Capillary Rheometer number of grams of polymer in 10 minutes. MFR is inversely proportional to viscosity; viscosity is directly proportional to molecular weight of the polymer. The higher the MFR, the lower the molecular weight.

Molecular weight distribution is determined by measuring the dynamic moduli of the polymer melt using rheological analyses. Figure 2.6 shows the viscosity shear rate plot for two Basic Fluoropolymer Data( 23 June 2003) 12 hypothetical polymers with different MW distributions. Crystallinity of virgin ( unmelted) PFA is 65 75%. DSC can be used to study melt and crystallization of PFA.

I 0 >

Item <IP_ADDRESS> Transitions PFA exhibits one first order transition at  5 ° Cin contrast to two temperatures for PTFE at 19 and 30 ° C. It has three second order transitions at  100,  30 and 90 ° C[ 18].

Item <IP_ADDRESS> Chemical Resistance Chemical properties of PFA are just as good as those of PTFE because of stable perfluorinated structure of the former. See section <IP_ADDRESS> for additional information. Table 2.8 and Figure 2.8 show actual test data for the effect of chemical exposure on the mechanical properties of PFA and MFA. MFA refers to a perfluoroalkoxy polymer made with PMVE ( perfluoromethyl vinyl ether, CAS number 1187 93 5) ` Broad MWD Narrow . MWD S1~ earRate ( k, g scale)

Figure 2.6 Viscosity shear Rate Plot of two Polymers [ 17]

Basic Fluoropolymer Data ( 23 June 2003)  13

Table 2.8 Effect of Immersion in Organic Chemical for 168 hours on PFA [ 19]

1Iydnxnrtons: lsxuclmie Muçblbn Mineral Oil Thlnene 99 1W 190 110 94 91 57 511 1W 1W 95 1W 02 0.5 0 0.7 Artunalic: aCr~ I obeawie 191 210 92 50 96 1W 02 02 Akthal: Bennl AkxuhDI 205 93 99 03 Ether Thtmh} t1r~ 1funun iS6 911 1W 0.7 Amine:

Aniline n Ritftmine F  li} lalcdinrm'me 1115 79 1 Li 94 96 96 1W 97 1W 03 0.4 0]

AlLidrycle:

Iansuiddhyde lIP 50 99 0.5 Kelonc Cydoliextame MoIh~ 1Ethyl Kekine Azerrçilieuone 156 80 202 92 50 50 1W 1W 1W 04 0.4 0.15 E~ 1ara: Umctliylplithalik w 1kitftcetaie 7' rS~ Puty1 Phoaphato 220 125 2W 98 93 91 1W 1W 1W 03 0.5 2.0 Chir& u tact Mod1) lena Chloiik Pchkirceth~ 1ene .

Tctmchlonde 121 77 96 97 1W 1W 1W Oil 2fl 23 Lblnr& 1vents Dm& iylforninmicle flmc{ L~' lsilrwcide flaccane 154 1119 101 96 95 92 1W 1W 1W 02 0.1 0.6 Miul& AnlTyuIride%:

Glacial J~ eIicAcid 11$ 95 1W 0.4 AceuicAnhydrkle 139 91 99 03 TdchlxrtxiceuicMid 196 50 1W 22 Basic Fluoropolymer Data( 23 June 2003)  14

  ~ ~ MIowM~ R A B:

C:

0:

E:

F:

C:

H:

I:

J:

K:

Item 2.3 Perfluorinated Ethylene Propylene Copolymer, FEP [ CAS number 25067 11 2J Item 2.3.1 Polymerization FEP is a copolymer of TFE and a hexafluoropropylene ( HFP) which can be produced, in an aqueous and a non aqueous media. Terpolymers of this class contain other monomers such as perfluoroalkyl vinyl ether ( e. g., PPVE) to improve stress crack resistance. Commercially, it is polymerized by free radical polymerization mechanism usually in an aqueous media via addition polymerization of TFE and hexafluoropropylene. The initiatorfor the polymerization is usually water soluble peroxide such as potassium persulfate. In general, the polymerization regime resembles that used to produce PTFE by emulsion polymerization. 2C 1~~ iiieDr~ In  1: £ LA~ flC MO~ ULU~

... L ~ J_ L. J_ L~ L .~ J_

2;~ bo~. f~ iiiari ~ L~ ith~ c~ rI~ n~ I: YIELD STRESS L J L I L L .. L L L J~ ~ t_

    Di~ Thon(%) ~ n~ M or~ neI:~ T~ E33 ~ YTE REA~ c ~ .4.. ~ ._ L. ~.. L. ._&_  L . L . L . 1_ .3   D~ m~ Uwi 1%) ~ m1) iI1odgIr~ I: ELUNQATTON AT~ FL~ M~     ~ ~ ... L. ~ L ~.. L. 3.. ... L .1.. . L.. . J... ... L. L .. L .. J.           .   a     ~ aiy~ ~ LL~ ME ~           2.~           : ~ Clohe~ enone~

Tduen& ~ 110 ° C Carbon tetredilc~ idej~ 77CC C~ meth~ fforrnamide ~ 40CC Methylene chloride ~ 4( 1 ° C Fuming nitric acid ~ 2~ 3~' C Fuming ~ ulflirioead ~ 23C Pho~ p~ ric e~* J~. S%~

Hydrogen peroxide ~ 0~( I .~ 23CC ZncthoriJe2S%~ 1~ O~ C Elhj'lene diemine © 11 ?`~ C Sodium hydroxkie ~ 120 ° C A ~ CD E F G 4 j 1~ L ~

Figure 2.8 Effect of Chemical exposure on the Mechanical Properties of Perfluoroalkoxy Polymer [ 20]

Basic Fluoropolymer Data( 23 June 2003)  15 Item 2.3.2 Properties Perfluorinated ethylene propylene copolymer polymers are fully fluorinated and melt processible. They have excellent chemical resistance and thermal stability. Melt viscosity of FEP is more than one million times lower than PTFE (< 1 ~ Pa. s). Specific gravity of FEP resins is in the range of 2.13 2.15. FEP polymers melt and flow and can be processed by typical thermoplastic techniques such as extrusion, injection molding and rotational molding. FEP resins are specified by ASTM Method D2 116, which also provides procedures or references to other ASTM methods for the measurement of resin properties. Figure 2.9 illustrates a segment of FEP molecule.

F F F F F F I I I I   c   c   C   c   c   c   I I I I F F F F F F~'   f~ F F Figure 2.9 A Segment of Perfluorinated Ethylene propylene copolymer Molecule Item<IP_ADDRESS> Molecular Structure FEP polymers have a similar structure to PFA except that randomly after every few TFE monomer units a comonomer ( e. g., HFP) appears in the molecule, as shown in the Figure 2.9. For example for a copolymer containing 13% by weight of PPVE, the ratio of TFE to PPVE is about 10 to 1. Ofcourse this ratio is an average value and the actual number of TFE units occurring between consecutive HFP groups may be more or less than 8. The perfluoromethyl pendent groups reduce the extent of crystallization as well as the size of individual crystallites.

liem <IP_ADDRESS> Molecular Weight and Crys/ allinity Similar to PTFE, molecular weight of FEP can not be measured by conventional techniques. Similar to PFA, MFR is used to characterize molecular weight of FEP. The higher the MFR, the lower the molecular weight. See section Item <IP_ADDRESS> for more information. Molecular weight distribution is determined by measuring the dynamic moduli of the polymer melt using rheological analyses. Figure 2.6 shows the viscosity shear rate plot for two hypothetical polymers with different MW distributions. Crystallinity of virgin ( unmelted) FEP is 65 75%. DSC can be used to study melt and crystallization of FEP.

item <IP_ADDRESS> Transitions FEP exhibits a single first order transition that is its melting point. Similarly to PTFE, FEP's melting point increases with pressure ( Table 2.9). The presence of the pendent group causes a lowering of melting point relative to PTFE. Melting of commercial FEP results in an 8% increase in volume. Crystallinity of parts after processing ( i. e., melting) depends on the cooling rate of the melt. Relaxation temperature of FEP increases with hexafluoropropylene content ofthe copolymer. FEP has a dielectric transition at  150 ° Cwhich is unaffected by the monomer composition or crystallinity ( specific gravity) [ 21]. Relaxation temperatures of FEP are shown in Table 2.10.

Basic Fluoropolymer Data( 23 June 2003)  16 Table 2.9 Effect of Pressnre on FEP Melting Point [ 22]

a 157  5 to 20 Item <IP_ADDRESS> Chemical Resistance Chemical properties of FEP are just as good as those of PTFE because of stable perfluorinated structure of the former. See Section <IP_ADDRESS> for additional information. Tables 2.11 2.13 show actual test data forthe effect of chemical exposure on the mechanical properties of FEP.

Table 2.11 Chemical Compatibility of FEP with Halogenated Solvents [ 25]

qip~ i I~/ J Chloroform Wets, insoluble at bailing point Ethylene Bromide 113% weight gain alter 24 hrat 100 ° C Fluoiinated Hdrocatbons Wets, swelling oOzU. N in boiling solvent Flnon> naphthatene Iliallubte atbailing paint some swelling Biwio: nitixThmzeno Insoluble atbailing paint, some swelling Pentaclilorobennainide Insoluble Perfluoroxytsne Insoluble at bailing paint, slight swelling Tettebrnoethane Insoluble at bailing point TetmSklornabylene Wets, some swelling alter 2 hrat 120CC Trichloruacthc Acid Insoluble at bailing point Trichhoroethylcue Insoluble at bailing pointafter t hr Table 2.10 Transitions Temperatures of FEP Melting [ 22]

Basic Fluoropolymer Data ( 23 June 2003)  17

Table 2.12 Chemical Resistance of FEP to Common Solvents [ 24]

Seiteist Lipesera Expoiusre rime WsEs2bt Gate, %

Temperatere, r 21J 12 no 13 Arotoso SO 12 inc 114 10 2; sk U Ileuzene lb 100 200 96 hr & br bhr 0.5 0.6 i. 0 Cathon Terachloride 25 50 10 100 200 12am l2ino 2 wk~

,% hr Sbr 0.6 1.6 1.9 2.5 3.1 Ethanbl ( 9595j 25 so 10 100 200 l2mo l2nio 2 wk bbr bbr 0 0 0 0.1 0.3 Ethyl Acolate 25 50 10 l2rno i2 no 2wk 0.5 0.1 0.1 Tohiene 25 50 10 12mm 12 trio 2wk 0.3 0.6 0.6 Basic Fluoropolymer Data ( 23 June 2003)  18

Table 2.13 Chemical Compatibility of FEP with Common Acids and Bases [ 26]

~ i:~ ~ : ~

Hydr~ hIoricMid 10% 10%

10%

20% 20% 25 50 70 RX~ 2O~ J i2ina l2ni~

l2itw ~ br ~, hr 0 0 0 0 0 Nitric Acid 10%

10% 25 70 l2mu l2uio 0 0.1 Sulfuiic Mid 30% 30%

30% 30% 25 70 L~ X) 2~ 12 mo 12am ~ br ~ br 0 0 0 0.1 S~ xIimunHythc~ dd~ 10%

10%

50%

50% 25 70 i~

2O~ 12am 12am 8hr & Iir 0 0.1 0 0 AmaioriiuniHydm~ dd~ m 10% 10% 25 70 l2ino 12am 0 0.1 Item 2.4 Optical Spectral Properties and Weathering Resistance ofFluoropolymers Tables 2.14 and 2.15 and Figure 2.10 through 2.13 provide optical properties including refractive index and transmission spectrum of perfluoropolymers. PTFE and other fluoropolymers are virtually transparent to ultraviolet light at of 50 p. m or less thickness, as can be seen from the data. Figure 2.14 illustrates the stability of dielectric constant and dissipation factor after ten years of outdoor exposure in south Florida. In contrast, most other plastics degrade extensively after a few years of outdoor exposure. For example, acrylonitrile butadienestyrenepolymer ( ABS) completely degrades after just three years of outdoor exposure, as indicated by total loss of elongation of exposed samples ( Figure 2.15).

Basic Fluoropolymer Data( 23 June 2003)  19

Table 2.14 Refractive Index of Perfluoropolymers per ASTM D542 [ 27]

C.)

E U)

I..

I.

Figure 2.10 Transmission Spectrum of PTFE ( Courtesy DuPont Fluoroproducts)

1~ 00 90 TO 50 50 40 30 20 0 W~ gUt~ pm Figure 2.11 Transmission Spectrum of FEP [ 28] 100 ~   1425micronT . ici 350 Wavelength, nm E 0.2 0.~ tO 1.4 1.82.2 3.0 7.0 9.0 12 15203050 Basic Fluoropolymer Data ( 23 June 2003) 100  20

I p p   Refi~ ctiveIndex ASTMD542 50 ( at 0346 jim) 135 Haze~,% ASSTM D1003 52 4 Light Tmnsrriissb; %

UV ( a25 o .40 jim)

Vithle ( t40 0J0 Jim)

Infrared ( 0.70 2~ 40pm) Spectmphotoxn ± y 0J} 25mm film thiehiess 77 91%

91 96% 96 98% C) C)

E to C CC I I

250 350 450 550 650 Wavelength, nm 100 Figure 2.12 Transmission Spectrum of FEP ( Courtesy DuPont Fluoroproducts)

60 443 20 200 300 400 500 600 700 800 900 WavoSngth ~ nm)

Figure 2.13 Transmission Spectrum of FEP, PFA and MFA [ 29]

Table 2.15 Optical Properties of PFA [ 30]

Basic Fluoropolymer Data ( 23 June 2003)  21

Table 2.17 Retention of Tensile Properties of FEP after 20 Years Outdoor Exposure in South Florida [ 32]

~ 0 1 2 3 4 8 ~ 7 0 9 10 Outdoor Expoo~ im, ysars .011 .0O1~

.~

Figure 2.14 Retention of Dielectric Constant and Dissipation factor after 10 years Outdoor Exposure in South Florida [ 33] Table 2.16 Tensile Properties of PTFE after 10 Years Exposure in South Florida [ 31]

a 2 I F~.

D~ slectr1cOon~ 1ant ~ U~ TJ11. L ______

D~ tslpationFictcr I I I r I I Basic Fluoropolymer Data ( 23 June 2003)  22

Break Elongation, % of initial retained Outdoor Exposure, Years Figure 2.15 Retention of Break Elongation of ABS after 3Years Outdoor Exposure [ 34]

Effect of Ozone on Fluoropolymers ( Thefollowing discussion has been adopted in its entirelyfrom Section 13.2.1 of Ebnesajjad, S., Fluoroplastics, Vol. 2: Melt Processible Fluoroplastics, William Andrew Inc., Norwich, NY, 2002) " Ozone is considered areactive substance against plastics due t ~ its~ abilityto readily degrade into an atom and a molecule of oxygen. The atomic oxygen is highly reactive, due to its unpaired electrons in its last orbital, allowing it to attack and etch most polymers. Polytetrafluoroethylene has been reported to be very resistant to etching by ozone in low earth orbit environment, where atomic oxygen is the most abundant species [ 3 5,36].

03 ~ O2+ O~

Resistance of polymers to ozone attack is studied in space environments in " actual" applications. In the laboratory, glow discharge or plasma etching is the common method for laboratory study of ozone effect. Plasma and low earth orbit environments are not equivalent. For instance, oxygen plasma contains a variety of other particles including electrons and free radicals in addition to atomic oxygen. In contrast, atomic oxygen is the dominant constituent of low earth orbit. 0 0.5 1.0 1.5 2.0 2.5 3.0 ` I 3.5 Basic Fluoropolymer Data ( 23 June 2003)  23 In general, oxygen uptake was least for PTFE and most for polyethylene in experiments in which a series of fluorinated polyolefins were exposed to ozone " out of glow." This means that plasma or glow discharge was used to produce atomic oxygen that etched the sample placed outside the discharge zone. The results of " out of glow" plasma etching and low earth orbit, by and large, are in agreement [ 37].

Maximum oxygen uptake decreases with an increase in the fluorine content of the polymers. For example, polyvinylidene fluoride took up less oxygen as a result of 03 exposure than polyethylene, though more than PTFE, in the same experiment [ 37]. The exception to this trend is polyvinyl fluoride, which has a higher etch rate than polyethylene ( Table 2.18). Why is PVF more susceptible to ozone attack than polyethylene?

Golub [ 38]] has proposed an explanation attributing the high etch rate of PVF to the ease offluorine formation from the decomposition ofthis polymer. Fluorine promotes degradation of molecular oxygen to its active atomic form ( 02   ~ 20) or by further reaction with PVF, thus enhancing the etch rate. Polyvinylidene Fluoride and FEP molecules have lower etch rates due to the higher stability of CF2 group to oxygen attack than CFH in PVF or CH2 in polyethylene. Both polyvinylidene Fluoride and copolymers oftetrafluoroethylene and ethylene ( ETFE) have low etch rates due to the protection provided to the CH2 groups bonded to CF2 groups. The ultimate stability is reached in the linear PTFE chain, which consists of all CF2 groups, with the exception of the few end groups."

Table 2.18 Relative Mass Loss Rates for Polymer Films Exposed to Low Earth Orbit [ 37]

Polymer ~

Polyirnide ( Kapton~) Mass Loss Rate I Fluorine to Carbon .

Ratio 0 Polyetherterphthalate ~ M~ lat~)

Polveth'qlene ( low densitv} 1 06 0 43 0 0 Polvethyletie ( high density) 0.~ 0 0 Pol~~ inyl Fluoride ( TedIar~ j 116 0,5 Polyvinylideiie Fluoride ( KynarX) . 1 PTFE ( TefIon~)  0.03 2 Tetrafluoroeth y lcne/ ilexafluoropropylene iTetlcinr_ FEP) 0.03 2 Basic Fluoropolymer Data ( 23 June 2003)  24 Item 3 Thermal Stability ( Thefollowing discussion has been adopted in its entiretyfrom Section 13.4.1 of Ebnesajjad, S., Fluoroplastics, Vol. 2: Melt Processible Fluoroplastics, William Andrew Inc., Norwich, NY, 2002) " Fluoroplastics are, generally, very stable at or below their specified maximum use temperatures. The rate of degradation of these plastics at higher temperatures is a function of their chemical structures in addition to temperature, time at temperature, and, to some extent, on the pressure and the atmosphere of decomposition. In actual processing, degradation is tracked by indirect measurement of molecular weight. Thermal exposure leads to a reduction in the molecular weight, which can be quantified by an increase in the MFR, heat of fusion of polymer, and specific gravity in controlled measurements.

Perfluoropolymers are more thermally stable than partially fluorinated resins. Thermal stability usually increases with the fluorine content, as do other basic properties of fluoroplastics like chemical resistance. Figure 3.1 [ Figure 13.50 in the reference text] shows a comparison of degradation rate ( weight percent per hour) as a function of temperature by thermogravimetric analysis ( TGA). It can be seen that for a given rate of degradation, say 0.1%, perfluoropolymers, that is PTFE, PFA, and FEP, require higher temperatures than ETFE. Among the perfluoropolymers, PTFE that has a linear unbranched structure, is more stable than PFA and FEP. The degradation rates of specific fluoropolymers have becirlisted in Table 3.1 [ Table 13.17 the reference text].

Degradation is usually measured and characterized by weight loss using TGA techniques while degradation products are identified by gas chromatography, infrared spectroscopy, and mass spectroscopy. The small amount of degradation requires TGA experiments to be conducted for several hours to allow accurate detection of weight loss. Table 3.2 [ Table 13.18 the reference text] gives a comparison of the composition products of the degradation of ETFE, FEP, and PFA. The most toxic compounds are perfluoroisobutylene ( PFIB) and carbonyi fluoride ( COF2)."

100 ~,

A . ~,

~~ A'

I~~ i: iII  rn~~.~ ~

.   ~ . ..... A'

2~ L~ X  I L~. ETFE J PFA44OHP U FEP100 0 PFA34O 0 PTFE 7A PTFE 6C I I 10 10.1 ° o. oi 0.00 1 250 275 300 325 350 375 400 425 450 475 500 525 550 Degrees Centigrade Figure 3.1 Degradation Rate of Fluoroplastics in Air [ 39]

Basic Fluoropolymer Data ( 23 June 2003)  25

Table 3.1 Degradation ( TGA) Rates of Fluoroplastics in Air as a Function of Time and Temperature [ 39]

% 1~ iLq~ 1Lt i.,] Y~ J~ 1Ir J~ 1in. Irciip.' C 1 IF L~ I~ tflb~ l~ IuI 150 2~ 0 0.31 DiMI 0.11 303 0.42 0.111' 0.14 325 0. t~ 7 350 FEP 205 ~. 05 303 ~ H.'] 3 ~ 0.05 350 0.45 0. L3 ° 0.1~

375 0.~ 7 4I~ XJ 3.2 PFA 1 303 0.15 0.115 ~ U. 05 0.117 350 0: 22 41~ 0.55 PFA 2 303 ~ U. 03 <~ 05 351. J 0.12 ~~ i. 03 0.115 4D3 02~

FiEk~ Pc~ th~ r PTFE 41X1 ~ n. oo 425 0.15 42.5 11.04*

525 255** ~ s5.0 GnmuI~ r PTFE 350 0.112 350 0.01)?

$~ X1 0.113 403 a. oud~

425 , 0.116 425 H. 06~

* E1t~ urlyraLulituuiin 11.5 b~ t Jh~ rb~ jimin~. run.

~ E3~ urlyrate J'mrn 3.3 U~ i5.6 hc~ ir~ ~ ~ TUfl.

** Odi~ ouipn~ iti~ riin c~ n~ i iu~ ur. Initial rni~ 255% p~ rh~ iiir. Tlu~ rurn. 1t~ quilibriurn Basic Fluoropolymer Data ( 23 June 2003)  26

Table 3.2 Degradation ( TGA) Products of Fluoropolymers in Air after 1 Hour at Temperature [ 39]

TEFZ&., 200 351) 5.3 0.11' S PEP 1100 4011 2.5 0.1103 °~ 10' S. 035 il. i~

PFA 3411 400 0.4.3 PEA 4411 41311 0.2~

TtiFZ1iL.~. 200 Oil'S ° FIFP LOU ° 0.64 1.2 2.7~ l 11 L01~

PEA 340 PEA 4411 0.01 1.2 0.53 0.53 12. 123~

4&)~

l~~ e~ rfluDrabucIb~ n~

Arti: 1kc~ tii this ~ n~ i1ytka1inr. hniqu~~ x vziiu~ L01Y~.~

r~ T1ii~~ cumin~ Lude~ i. 1!~ CO~ fairn n~ c~ idaiian d~ h~~ th'p{ c~ ne uniL~

` Endu~ k~ 11. 19' i'i~ nI~ CIf~ iCOE Basic Fluoropolymer Data ( 23 June 2003)  27

References 1. Gangal, S. V., " Polytetrafluoroethylene, Homopolymers of Tetrafluoroethylene," in Encyclopedia ofPolymer Science and Engineering, 2nd ed., 16: 577   600, John Wiley & Sons, New York, 1989.

2. Lee, J. A., Observ. of Individual Fluorine Atoms from Highly Oriented Polytetrafluoroethylene Film by Atomic Force Microsc., Marshall Space Flight Ctr., Alabama.

3. Sperati, C. A., and Starkweather, H. W., Jr., Adv. Polym.. Sci., 2: 465, 1961.

4. Moynihan, R. E., " The Structure of Perfluorocarbon Polymers. Infrared Studies on Polytetrafluoroethyelne," J. Am. Chem. Soc., 81: 1045   1050, 1959.

5. K. L. Berry and J. H. Peterson, .1 Am. Chem. Soc., 73: 5195, 1951; and Doban, R. C., Knight, A. C., Peterson, J. H., and Sperati, C. A., Paper Presented at 130th Meeting, Am. Chem. Soc., Atlantic City, Sep., 1956.

6. Molecular Weight of Polytetrafluoroethylene, R. C. Doban, A. C. Knight, J. H. Peterson and C. A. Sperati, DuPont Co., presented at 130 th Meeting, American Chemical Society, Atlantic City, N. J., September 16 21, 1956.

7. Melting and Crystallization Behavior of Poly ( tetrafluoroethylene). New Method for Molecular Weight Measurement of Poly ( tetrafluoroethylene) using a Differential Scanning Calorimetry, T. Suwa, M. Takehisa and S. Machi, JofAppl. Polymer Sci., Vol 17, pp 3253 3257, 1973.

8. McCrum, N. G., " An Internal Friction Study of Polytetrafluoroethylene," Jour. Polym. Sci., 34: 355, 1959.

9. Table 2.7, Reprinted by permission from Reference 14. 10. Table 13.1, Reprinted by permission from Reference 14. 11. Table 13.3, Reprinted by permission from Reference 14. 12. Table 13.2, Reprinted bypermission from Reference 14. 13. Table 13.4, Reprinted bypermission from Reference 14.

14. Ebnesajjad, S., Non Melt Processible Fluoroplastics: The Definitive User ~ Guide and Data Book, Plastics Design Library, William Andrew Publishing, Norwich, NY, 2000.

15. Ebnesajjad, S., Melt Processible Fluoroplastics: The Definitive User's Guide and Data Book, Plastics Design Library, WilliamAndrew Publishing, Norwich, NY, 2002.

16. Scheirs, J., Modern Fluoropolymers, Ed., Wiley Series in Polymer Science, John Wiley & Sons, New York, 1997.

17. Figure 3.37, Reprinted by permission from Reference 15.

18. Gangal, S. V., " Tetrafluoroethylene Perfluorovinyl ether Copolymer" in: Kirk Othmer Encyclopedia ofChemical Technology, 4th ed., 11: 671   683, John Wiley & Sons, New York, 1994.

Basic Fluoropolymer Data( 23 June 2003)  28

19. Table 12.2, Reprinted by permission Reference 15.

20. Vita, G., and Pozzoli, M., MFA: Technical Paper, ANew Perfluoropolymer for Molding, Extrusion and Coating Applications, Ausimont S. p. A., Italy.

21. Eby, R. K., and Wilson, F. C., I App!. Phys., 33: 2951, 1962.

22. Table 2.8, Reprinted by permission Reference 15. 23. Table 2.9, Reprinted by permission Reference 15. 24. Table 12.3, Reprinted by permission Reference 15. 25. Table 12.5, Reprinted by permission from Reference 15. 26. Table 12.4, Reprinted by permission from Reference 15. 27. Table 13.2, Reprinted by permission from Reference 15. 28. Figure VI. 14, Reprinted by permission from Reference 15. 29. Figure 13.98, Reprinted by permission from Reference 15. 30. Figure 13.40, Reprinted by permission from Reference 15. 31. Table 13.32, Reprinted by permission from Reference 15. 32. Table 13.28, Reprinted by permission from Ref Reference 15. 33. Figure 13.70, Reprinted by permission from Reference 15.

34. The effect ofUV Light and Weather on Plastics and Elastomers, published Plastics Design Library, William Andrew Publishing, Norwich, NY, 1997.

35. Leger, L. J., and Visentine, J. T., J. Spacecraft Rockets, 23: 505, 1986.

36. Leger, L. J., Visentine, T., and Santos Mason, B., International SAMPE Technical Conference, 18: 015, 1986.

37. Golub, M. A., " Reactions of Atomic Oxygen [ O( 3P)] with Polymer Films," ol. Symp. 53: 379   391, Huthig & WepfVerlag. Basel, 1992.

38. Golub, M. A., and Wydeven, T., Polymer Degrad. Stab., 22: 325, 1988.

39. Baker, B. B., and Kasprzak, D. J., Thermal Degradation of Commercial Fluoropolymer in: Air, Polymer Degradation andStability, 42: 181   188, 1994.

Basic Fluoropolymer Data ( 23 June 2003)