Preparation and properties of ionic oxymethylene copolymers

Oxymethylene copolymers containing pendant ionic groups have been prepared and some of their properties examined. The ionic copolymers differ from non‐ionic copolymers in that the crystalline order is poorer, which results in increased transparency and ductility and in decreased stiffness and strength. The reduction of crystalline order is dependent upon the rate of cooling from the melt. Melt viscosity and temperature dependence of melt viscosity of ionic copolymers are higher than those of non‐ionic copolymers. Introduction of ionic groups also increases water sensitivity. Ionic oxymethylene copolymers neutralized with divalent cations were examined briefly, and these show some unusual aging effects.