Abstract: N-vinylformamide is polymerized with or without other water-soluble monoethylenically unsaturated monomers and with or without water-insoluble monoethylenically unsaturated monomers in not less than 30% strength by weight aqueous monomer solutions in the presence of a polymerization initiator at not more than 150.degree. C. in a kneader by a method in which the polymerization is carried out to such an extent that the initially formed water-containing polymer gel disintegrates into fine particles and the finely divided polymer obtainable in this manner is hydrolyzed, preferably in the kneader, so that not less than 0.1 mol % of the N-vinylformamide units present in the polymer are converted into vinylamine units. The polymers obtainable in this manner dissolve readily in water. The aqueous solutions are used, for example, in papermaking and tertiary oil production.

Abstract: A styrene derivative carrying N-acethylchito-oligosaccharide chains, a polystyrene derivative carrying N-acetylchito-oligosaccharide chains on the side chains as well as a method for preparing these compounds are herein disclosed. The method for preparing the styrene derivative comprises reacting N-acetylchito-oligosaccharide lactone with vinylbenzylamine or a derivative thereof while the method for preparing the polystyrene derivative comprises polymerizing the styrene derivative. These derivatives can be employed as biomedical materials, in particular as materials for cell culture.