STRUCTURAL STUDIES OF POLY(PARA-PHENYLENE), POLY(2,5-THIENYLENE) AND THEIR DERIVATIVES BY SOLID-STATE NMR OF H-1 AND C-13

Transient techniques in NMR of H-1 and C-13 were used to study the che mical and physical structures of solid poly(p-phenylene) (PPP), poly(2 ,6-dimethyl-p-phenylene oxide) (PDMPO), poly(p-phenylene sulfide) (PPS ), poly(p-biphenylene sulfide) (PPBS), poly(p-phenylene selenide) (PPS e), poly(p-biphenylene selenide) (PPBSe), poly(2,5-thienylene) (PT), p oly (3-methyl-2,5-thienylene) (PMT), and poly (p-phenylene-co-2,5-thie nylene) (PPPT) of different monomer ratios. C-13 NMR confirmed the exp ected chemical structure for homopolymers, and indicated a random dist ribution of monomer units in PPPT. Relative fractions of crystalline a nd interfacial regions were determined by measurements of H-1 magnetic relaxation, C-13 CP/MAS NMR, and XRD. (c) 1994 John Wiley & Sons, Inc .