The Norwegian Pollution Control Authority (SFT) commissioned a literature survey on incineration of fluoropolymer materials, overviewing the available literature on formation of greenhouse gases until August 2008. The survey provides the foundation on which decisions for the future needs for further investigations will be made. Suggestions for sampling were also part of the study.

*Read the full report online http://fluoridealert.org/wp-content/uploads/huber-2009.pdf

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1 Summary

This report consists of two parts. (1) An overview of existing commercially available fluoro-polymer materials and their properties, application area, production and consumption levels is given, and (2) a review of the existing scientific literature on the possible formation of greenhouse gases upon fluoro-polymer incineration and the potential greenhouse effects.

Fluoropolymers are special plastics that are used in a great variety of applications because of their unique properties. They are used in e.g. cable coating, coated cookware, sports and extreme weather clothing, food handling and medical equipment. In 2004, the global consumption of fluoropolymers reached almost 133 000 tons.

Polytetrafluoroethylene (PTFE) is worldwide the most produced and consumed fluoro-polymer followed by polyvinylfluoride (PVF) and a co-polymer of tetrafluoroethylene and hexafluoropropylene (PVDF and FEP). Therefore, it is assumed that these also are the major fluoropolymers to end up in municipal waste incinerators, with minor contributions from a multitude of other recently introduced fluoro-polymers and -elastomers.

The literature survey was conducted by using comprehensive and widely appreciated search engines such as SciFinder, ISI Web of Knowledge, and PubMed, along with specialized technical books on fluoropolymers. Furthermore, homepages of fluoropolymer companies were scrutinized on their product range and applications. The report ”Assessment of information assessable on Teflon and degradation products of Teflon (CAS 9002-84-0)” was reviewed and updated on missing and new literature (Tobiesen, 2005).
A considerable amount of scientific literature was found on the thermal stability and decomposition products of PTFE for temperatures between 400 and 600°C, the temperature range where PTFE and most other fluoro-polymers start to degrade. The main degradation products were found to be fluoroalkanes and alkenes, hydrogen fluoride, oxidation products (epoxides, aldehydes and acids), and fluoro-polymer particulates in this temperature range.

However, municipal waste incineration is carried out at about 850°C, and to our best knowledge, any emissions of fluoro-polymer degradation products from household waste incineration have not been monitored yet. On the laboratory scale the degradation of fluoro-polymers, primarily PTFE, has been investigated in the temperature range 700-1050°C, yielding CF4 (PFC-14), CHF3 (HFC-23), C2F6 (PFC-116), tetrafluoroethene (TFE) and hexafluoropropene (HFP) as major products. The kind of compounds formed is strongly dependent on the incineration conditions like temperature, moisture, oxygen content, use of catalysts etc. Few studies have been published on the incineration degradation products of other fluoropolymers than PTFE.

The most potent greenhouse gases formed by fluoropolymer incineration are compounds containing C–F bonds, which absorb electromagnetic radiation in the 1000-1400 cm-1 range where the atmosphere is rather transparent. Perfluoropolymers will therefore presumably produce the most efficient greenhouse gases upon incineration.

Incineration of fluoropolymer containing products has a great potential to contribute considerably to the total greenhouse gas emissions of Norway, but due to the lack of sound data on the fate of fluoropolymers in Norway as well as of the chemical reactions in the different types of MWI plants in Norway, no exact amounts can be given at this stage. On-site investigations for revealing a realistic impression on the compounds formed in Norwegian municipal incinerators are necessary in order to assess the extent and the composition of the organofluorine emissions. In addition, a quantitative life cycle assessment for the imported PTFE and other fluoropolymers should be conducted to fill knowledge gaps about the fate of fluoropolymers in Norway.

The scientists Dr. Sandra Huber, Dr. Morten K. Moe, Dr. Norbert Schmidbauer, Dr. Georg H. Hansen and Dr. Dorte Herzke contributed to the report.

Table of content

Contents …………………………………………………………………………………………………… 1
1 Summary …………………………………………………………………………………………… 3
2 Abbreviations …………………………………………………………………………………….. 5
3 Background and purpose ……………………………………………………………………. 7
4 Types of fluoropolymers …………………………………………………………………….. 9
4.1 Perfluorinated polymers …………………………………………………………………. 9
4.2 Partially fluorinated polymers ……………………………………………………….. 10
4.3 Fluoroelastomers …………………………………………………………………………. 11
4.4 Other fluorine containing polymers ……………………………………………….. 12
4.4.1 Fluorinated Polyurethans ……………………………………………………. 12
4.4.2 Hexafluoroisopropylidene-containing polymers ……………………. 13
4.4.3 Polyfluoroacrylates and -methacrylates ……………………………….. 13
4.4.4 Perfluoropolyethers …………………………………………………………… 13
4.4.5 Perfluorinated ionomers …………………………………………………….. 14
5 Production and consumption of fluoropolymers ………………………………… 14
5.1 Consumption of fluoropolymers ……………………………………………………. 15
5.2 Consumption of fluoroelastomers ………………………………………………….. 17
5.3 Future perspectives ………………………………………………………………………. 18
6 Thermal degradation of fluoropolymer materials ……………………………… 19
6.1 Properties and stability of fluoropolymers ………………………………………. 19
6.2 Thermal degradation experiments with fluoropolymers ……………………. 24
7 Greenhouse potential of fluoropolymer combustion products ……………. 31
7.1 Thermal degradation products of fluoropolymers …………………………….. 31
7.2 Possible contribution of incineration of fluoropolymers to global warming ……………………………………………………………………………………… 34
8 Conclusions and evaluation of the need for further studies ………………… 36
8.1 Recommendation on future investigations ………………………………………. 36
9 References ……………………………………………………………………………………….. 38
Appendix 1 : Review of the SFT report on PTFE …………………………………….. 43
Appendix 2; List of Fluoropolymers ………………………………………………………… 49
Appendix 3: List of intermediates produced by Daikin (Daikin Industries, 2008). ……………………………………………………………………………… 55

Abbreviations

1,1,3-TCTFP 1,1,3-TriChloroTriFluoroPropene
1,3-DCTFP 1,3DiChloroTetraFluoroPropene
6F Hexafluoroisopropylidene

BMA Butyl methacrylate

CDFA ChloroDiFluoroAcetic acid
CFC ChloroFluoroCarbon
c-OFB OctaFluoro cyclo-Butane
CPFP ChloroPentaFluorPropene
CPTFE ChloroPolyTriFluoroEthylene
CTFE chlorotrifluoroethylene
CTFE ChloroTriFluoroEthylene

DCFA DiCHloroFluoroAcetic acid
DCHB 1,2-DiChloroHexafluorocycloButane
DFA DiFluoroAcetic acid

E Ethylene
ECTFE co-polymer of ethylene (E) and ChloroTriFluoroEthylene (CTFE)
EFEP co-polymer of ethylene (E), tetrafluoroethylene (TFE) and hexafluoropropylene (HFP)
EHA Ethylhexyl acrylate
ETFE co-polymer of Ethylene (E) and TetraFluoroEthylene (TFE), ethylene tetrafluoroethylene
EVE Esther Vinyl Ether

FDD FluoroDibenzoDioxine
FDF FluoroDibenzoFuran
FEP co-polymer of tetrafluoroethylene (TFE) and hexafluoropropylene (HFP)

GC-MS Gas Chromatography Mass Spectrometry
GWP Global Warming Potential

HCFC HydroChloroFluoroCarbon
HFC HydroFluoroCarbon
HFIB HexaFluoroIsoButylene
HFIBO HexaFluoroIsoButylene Oxide
HFIFA 1,1,1,3,3,3-hexafluoroisopropyl ?-fluoroacetate
HFIMA 1,1,1,3,3,3-hexafluoroisopropyl methacrylate
HFP HexaFluoroPropylene
HFPO HexaFluoroPropylene Oxide
HPFP 1-HydroPentaFluoroPropene
HTE co-polymer of Hexafluoropropylene (HFP), Tetrafluoroethylene (TFE) and Ethylene

IPCC Inter-governmental Panel on Climate Change

MA Methyl acrylate
MFA MonoFluoroAcetic acid
MFA co-polymer of tetrafluoroethylene (TFA) and perfluoromethylvinylether (PMVE)
MTFA MethylTriFluoroAcrylate
MW Molecular Weight
MWI Municipal Waste Incinerator

NIOSH National Institute for Occupational Safety and Health
NMR Nuclear Magnetic Resonance

P Propene
PAVE PerfluoroAlkyl VinylEther
PCTFE Poly ChloroTriFluoroEthylene
PDMS PolyDiMethylSiloxane
PEVE PerfluoroEthyl VinylEther
PFA PerFluoroAlkan
PFA PerFluoroAlkoxy; co-polymer of tetrafluoroethylene (TFE) and perfluoropropyl vinyl ether (PPVE)
PFA7 Poly-2,2’3,3′,4,4′,5,5′,6,6′,7,7′,7″-tridecafluoroheptylacrylate
PFMA7 Poly-2,2’3,3′,4,4′,5,5′,6,6′,7,7′,7″-tridecafluoroheptylmethacrylate
PFBE PerFluoroButylEthylene
PFCA PerFluoroCarboxylic Acid
PFEPE co-polymer of polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoropropylether
PFIB PerFluoroIsoButene
PFOA PerFluoroOctanoic Acid
PFPE PerFluoroPolyEther
PHFIFA Poly(1,1,1,3,3,3-hexafluoroisopropyl ?-fluoroacetate)
PHFIMA Poly(1,1,1,3,3,3-hexafluoroisopropyl methacrylate)
PMNFHS PolyMethylNonaFluoroHexylSiloxane
PMTFPS PolyMethylTriFluoroPropylSiloxane
PMVE PerfluoroMethylVinylEther
PPVE PerfluoroPropyl VinylEther
PSEPVE Perfluoro-2-(2-fluoroSulfonylEthoxy) PropylVinylEther
PTFE PolyTetraFluoroEthylene
PTFEMA Poly(2,2,2-trifluoroethyl methacrylate)
PVDF Poly Vinylidene Fluoride
PVF PolyVinyl Fluoride

RF Radiative Forcing

SAR Second Assessment Report
SFT Norwegian Pollution Control Authority
SSB Statistics Norway

TAR Third Assessment Report
TCTFE 1,1,2-TriChloro-1,2,2-TriFluoroEthane
TFA TriFluoroAcetic acid
TFE TetraFluoroEthylene
TFEMA 2,2,2-trifluoroethyl methacrylate
TFEO TetraFluoroEthylene Oxide
TFE-P co-polymer of TetraFluoroEthylene (TFE) and Propylene
TFMAA -(TriFluoroMethyl) Acrylic Acid
TFP 3,3,3-TriFluoroPropylene
TH Time Horizon
THV terpolymer of Tetrafluoroethylene (TFE), Hexafluoropropylene (HFP) and

Vinylidene Fluoride (VF2/VDF)
VDF,VF2 Vinylidene Fluoride (1,1-difluoroethylene)
VOC Volatile Organic Compond

XFDA Poly(1H,1H,2H,2H-perfluorodecyl acrylate)
XFDMA Poly(1H,1H,2H,2H-perfluorodecyl methacrylate)

*Read the full report online http://fluoridealert.org/wp-content/uploads/huber-2009.pdf