RESEARCH ON MONOMER STRUCTURES AND REACTI VITY OF POLY(ARYL ETHER KETONE)S

Monomers of poly(aryl ether ketone)s family, such as, 4,4'-hydroquinon e (PD), 4,4'-biphenol(S-3) and 4,4'-difluorine benzophenone have been researched by uh initio RHF method. Results obtained show that these m onomers have different torques in their aromatic rings. S-3 has a dihe dral angle of 51.8 degrees, its reactivity is a bit stronger than that of PD, but it introduced more active branching points. Thus, polymer DPEEK from S-3 has more serious chain branching and is more difficult in crystallizing than PEEK from PD. And also, it is found that there i s a kind of red negative ion in DPEEK solution of concentrated H2SO4.