By the Wurtz reductive coupling reaction of dichloromethylphenethylsilane (D) and trichlorosilane (T), trichloromethylsilane or trichlorophenylsilane, two series of branched copolysilanes, polymethylphenethylsilene-co-methylsilynes and polymethylphenethyl

This work investigates the chemical composition and the structure of poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibres using solid state NMR. CP-DD-MAS 13C NMR including dephasing delay experiments permits to determine the chemical composition of PBO. Studying molecular dynamic of PBO (wide line 1H NMR), the structure of PBO is examined. According to the model of Kitagawa et al., the structure of PBO is then explained.