Studies on the Chemical Structures of Polycondensation Copolymers by NMR Spectroscopy

The possibility of finding the heterolinkages of the various kinds of polycondensation copolymers by high resolution NMR was examined and the followings became clear. (1) In case of the homologous type of copolymers (copolyester ctc), it is in general able to detect the heterolinkages when the units to be observed are joined by the aromatic and the saturated aliphatic groups. And the easiness of the detection is as follows; copolyester >copolyamide >copolyurethane> copolyurea. (2) In case of the heterogeneous type of copolymers (copolyurethane-carbonate, copolyamideurea, copolyamide-urethane, copolyurea-urethane, copolyester-urethane, copolyester-amide), the possibility is determined by the difference of the aromaticity and the saturated aliphaticity joined to the unit to be observed and also by the difference of the kinds of linkages. (3) Poly (neopentyl terephthalate-co-sebacate) obtained by the molten-state polycondensation is almost random and copolyurethane-carbonate obtained by the interfacial polycondensation have somewhat blockness character.