Chemistry of fluorocarbon elastomers

Logothetis, A. L.

doi:10.1016/0079-6700(89)90003-8

Cited by 149 publications

(113 citation statements)

References 32 publications

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“…The carboxylate end groups are formed from the hydrolysis of the sulphate initiator chain ends and form ionomeric crosslinks with Mg 2ϩ , which is added as MgSO 4 to coagulate the emulsion polymerization. 7,8 TAIC acts as a plasticizer to the polymer and the combination of shear, heat, and plasticization during milling, allows a more efficient formation of ionomeric aggregates. The improvement of tensile properties therefore takes place when TAIC is milled in the fluoroelastomer.…”

Section: Resultsmentioning

confidence: 99%

The use of crosslinking promoters in the ?-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether).I

Forsythe

Hill

Logothetis

et al. 1999

J. Appl. Polym. Sci.

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Incorporation of 1 wt % of triallyl isocyanurate (TAIC) significantly enhanced the radiation crosslinking of the perfluoroelastomer, poly(tetrafluoroethyleneco-perfluoromethylvinyl ether) (TFE/PMVE). The dose for gelation was lowered by 70% with the presence of TAIC. The additive also improved the tensile properties of TFE/ PMVE both before and after crosslinking by irradiation. Higher radical yields were obtained with the presence of TAIC at 77 K, indicating the crosslinking promoter was acting as a radical trap. ESR studies showed that radiolysis of TAIC and subsequent photobleaching cleaved an allyl branch from the ring structure. Upon thermal annealing, an allyl radical on the TAIC molecule was observed.

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Section: Resultsmentioning

confidence: 99%

The use of crosslinking promoters in the ?-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether).I

Forsythe

Hill

Logothetis

et al. 1999

J. Appl. Polym. Sci.

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“…Carboxylate end groups are present in the elastomer and originate from hydrolysis of the sulphate initiator chain ends. 3 The perfluorophenyl and hydrogen elastomers showed almost identical tensile properties compared to the neat elastomer, both before and after irradiation. The tensile strengths at break of the elastomers dropped to half of their original value at a dose of 16 kGy.…”

Section: Room Temperature ␥-Irradiationmentioning

confidence: 92%

“…The chemical crosslinking of perfluoroelastomers has been reviewed in detail by Logothetis. 2,3 The effects of these functional groups on the radiation crosslinking of TFE/PMVE were investigated first by Logothetis. 4 He used electron beam irradiations and he studied the chemical and physical properties of the crosslinked polymers.…”

Section: Introductionmentioning

confidence: 99%

The use of crosslinking promoters in the ?-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether). II.

Forsythe

Hill

Logothetis

et al. 2000

J. Appl. Polym. Sci.

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Incorporation of 0.5 mol % of nitrile and bromine functionalities was found to enhance the radiation crosslinking of the copolymer of tetrafluoroethylene-co-perfluoro(methylvinyl ether) (TFE/PMVE) by a factor of 2 for ␥-irradiations carried out at room temperature to doses in the range 0 -50 kGy. The functional groups, nitrile, perfluorophenyl, and hydrogen were found to greatly enhance crosslinking well below the glass transition temperature of TFE/PMVE (276 K). Increased amounts of gel formation as well as improved tensile properties were obtained for irradiations carried out below the T g of the polymers containing functionalized monomers. These functional groups appear to be acting as catalysts for the radiation crosslinking of TFE/PMVE but they do not get incorporated into the crosslink.

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“…Copolymers containing vinylidene fluoride (VDF) are of interest since they can be thermoplastics, [4,5] elastomers [6][7][8] or thermoplastic elastomers. [3] The radical copolymerization of VDF with functional fluoromonomers has been studied by numerous authors and was reviewed recently.…”

Section: Full Papermentioning

confidence: 99%

Radical Copolymerization of Vinylidene Fluoride with 8‐Bromo‐1H,1H,2H‐perfluorooct‐1‐ene: Microstructure, Crosslinking and Thermal Properties

Sauguet¹,

Améduri²,

Boutevin³

2007

Macro Chemistry & Physics

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An original synthesis of 8‐bromo‐1H,1H,2H‐perfluorooct‐1‐ene (BDFO) and its radical copolymerization with vinylidene fluoride (VDF), initiated by 2,5‐bis(tert‐butylperoxy)‐2,5‐dimethylhexane at 134 °C, are presented. The fluorinated bromoalkene was obtained by dehydrobromination of 1,8‐dibromo‐1H,1H,2H,2H‐perfluorooctane in a satisfactory yield. Although BDFO did not homopolymerize under radical initiation, it did copolymerize with VDF. The compositions of the resulting random type copolymers were calculated by means of 19F NMR spectroscopy and allowed the quantification of the respective amounts of both comonomers in the copolymers, showing good incorporation of the brominated monomer. Nevertheless, obtaining PVDF copolymers containing a high molar percentage of BDFO in good yields was difficult to achieve from initial molar ratios of BDFO higher than 9.2 mol‐%. Radical terpolymerization of VDF, BDFO and hexafluoropropene (HFP) was also successfully achieved. BDFO contents in these co‐ or terpolymers ranged from 3.6 to 12.2 mol‐%. The bromoalkene acted as a cure site monomer and the resulting poly(VDF‐co‐BDFO) copolymers were crosslinked via the bromine atom in the presence of a triallyl isocyanurate/peroxide system. The materials obtained led to more thermally stable copolymers than the uncured ones and their thermostabilities were compared to those of commercially available poly(VDF‐co‐HFP) copolymers crosslinked using diamines.magnified image

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Chemistry of fluorocarbon elastomers

Cited by 149 publications

References 32 publications

The use of crosslinking promoters in the ?-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether).I

The use of crosslinking promoters in the ?-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether).I

The use of crosslinking promoters in the ?-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether). II.

Radical Copolymerization of Vinylidene Fluoride with 8‐Bromo‐1H,1H,2H‐perfluorooct‐1‐ene: Microstructure, Crosslinking and Thermal Properties

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