LIVING FREE-RADICAL COPOLYMERS OF PERFLUORO-2,5-DIAZAHEXANE 2,5-DIOXYL AND HEXAFLUOROPROPYLENE

Reaction of excess perfluoro-2,5-diazahexane 2,5-dioxyl with hexafluoropropylene at room temperature gives purple, alternating copolymers having stable living nitroxide end-groups. Number-average molecular weights of these copolymers have been determined by spectrophotometry and by reaction with potassium iodide, which gives iodine. Living copolymers are chain-extended by reaction with fluoro-olefins; reaction with perfluorobuta-1,3-diene gives dead products which contain residual unsaturation and which are crosslinked by reaction with living copolymer. Some new dead alternating copolymers have been prepared by reaction of the dioxyl with excess fluoro-olefin; all have low glass transition temperatures.