Die Copolymerisation von Vinylacetat und Divinyladipat. Vernetzung und Cyclisierung

Abstract

The reactivity ratios for the vinyl acetate-divinyl adipate system are determined. Both valuesr _{V Ac} andr _{DV A} are near to unity. The reactivity of the pendent double bond is very low and soluble polymers are formed far over the critical conversion calculated with anr-value of the pendent double bonds equal to unity. Contrary to this a high portion of intramolecular cyclization occurs, presumably leading to chain units of the type

amounting to 10% of the total number of divinyl adipate units in the chain in systems with an initial monomer concentration of 95% and to 23% in systems with a monomer concentration of 50%. The reactivity ratio of the pendent double bond is estimated. The main reason for the high conversion for gel formation is the low rate of intermolecular reaction of pendent double bonds. In this respect cyclization plays a minor role.