Crystal structure, crystallization kinetics and morphology of a new polyimide

Abstract

Abstract A new semicrystalline polyimide has been synthesized from 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 2,2‐dimethyl‐1,3‐(4‐aminophenoxy)propane. The polymer has a high glass transition temperature of 230°C and a melting temperature of 325°C. Its overall crystallization rate between 240 and 325°C is quite fast ( t 1 / 2 <10min) and relatively insensitive to the crystallization temperature. Although the degree of crystallinity obtained is dependent on the crystallization conditions, it can be as high as 50%. The polymer's morphology, which was examined with transmission electron microscopy (TEM), has a randomly stacked, ribbon‐like, lamellar texture. Both TEM and polarized light microscopy show that mature spherulites do not develop. The crystal unit cell, which was determined from wide‐angle X‐ray diffraction measurements on highly oriented films, is monoclinic with a = 0.960nm, b = 0.582nm, c = 2.46nm and γ = 81.1°.