Novel random copoly(arylene ether-thioether ketone)s based on 2,2-bis(4-mercaptophenyl)propane and 4,4′-dihydroxybiphenyl: Synthesis and properties

A series of novel poly(arylene ether-thioether ketone) random copolymers were synthesised by copolymerisation of 4,4′-difluorobenzophenone with bis(N,N-dimethyl-S-carbamate) of 2,2-bis(4-mercaptophenyl)propane (MBTA) and 4,4′-dihydroxybiphenyl (BP). The syntheses were performed using a one pot polymerisation method starting from different mole percentages of BP with respect to MBTA, varying from 20% to 80%. The copolymers were obtained in good yields and had molecular weights in the range 10,000–17,000 as determined by GPC. The structural proof was provided by ¹H-NMR spectroscopy. In order to study the effect of the copolymerisation on the thermal properties and crystal behaviour, also the poly(ether biphenyl ether ketone) homopolymer (PEBEK) has been synthesised using the same polymerisation method. The TGA analysis shows that the high stability of PEBEK is only slightly affected by the introduction of co-units in the chain. The copolymers with an amount of PEBEK variable from 80 to 50 mol% are crystalline, with percentage of crystallinity and melting temperature which decrease as the co-unit content increases. The samples with lower amount of PEBEK (40 and 20 mol%) are amorphous. The T_g values tend to decrease with the reduction of the percentage of PEBEK units.