Radiation‐induced polymerization at high pressure of cis‐ and trans‐1,3,3,3‐tetrafluoropropene in bulk and with tetrafluoroethylene

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Abstract
The radiation‐induced polymerization of cis‐ and trans‐1,3,3,3‐tetrafluoropropene in bulk and with tetrafluoroethylene was studied at pressures between 5000 and 15000 atm and temperatures between 21 and 100°C. At 103 rad/hr the homopolymerization rates range from about 10−4 to 1%/hr. The activation enthalpy and volume are about 8 kcal/mole (33 kJ/mole) and −10 cm3/mole, respectively, for both isomers. The cis isomer polymerizes about twice as rapidly as the trans isomer. The latter freezes in the experimental range of temperature and pressure; the polymerization rate is very low in solid phase. Polymer intrinsic viscosities increase with polymerization pressure and decrease with polymerization temperature; the largest value obtained was 0.23 dl/g. In the copolymerizations all reactivity ratios favor incorporation of tetrafluoroethylene by factors of 6–16. The preference is stronger when the trans isomer is used.