摘要 |
<p>Heterocyclic polymers contain units of formula. (in which R' and R2 are organic 2-1000C radicals, opt. contg. 1-1000 Si, F, Cl, Br, N, S, P, B and/or O atoms; R3 is NH or CH2; R4 is -NHCON=, -N=C-(O-)2, -NH-SO-N=, -N=S-(O-)2, - NH-C(=S)-N= -N=C-(S-)2, -S-S(=O)-N=, -S-C(=S)-N=, -S-C(=O)-N=, -O-S(=O)-N=, -O-C(=S)-N=, -NH-S(=O)-N=, -NH-C(=S)-N= or (II) - (IV) and where R3 is CH2, R4 may also be -O-CO - NH=). The polymers, opt. mixed with solvent, can be used for prodn. of 'Textolite' (RTM), moulding materials, adhesives, grinding tools, coatings or filters. The prods. retain their mechanical and dielectric properties at 300-400 degrees C and above. Synthesis can be combined with mfr. of prods., avoiding previous sepn. and purifn. of the polymer.</p> |