Structure determination of the amorphous perfluorinated homopolymer: Poly[perfluoro(4-vinyloxyl-1-butene)]

The low molecular weight samples were examined to assign the nuclear magnetic resonance (NMR) signals, and to study the cyclic structure and the end group structure for poly[perfluoro(4-vinyloxyl-1-butene)]. While the penta-cyclic structure was dominant, the hexa-cyclic structure also existed. The ratio was penta/hexa = 0.84/0.16. No preference of cyclic structure (penta- or hexa-cyclic) changed from the initial to the final stage of polymerization. The polymerization temperature did not affect to the ratio of cyclic structures, whereas the modification at side chain part could. The end group was observed, (CH3)2CHOCOO for initiator end, CF2Cl for chain transfer end, then only initiator end group changed to CF3 with fluorination.