Effect of copolymerization on crystallization kinetics of semicrystalline polyimides

Isothermal melt crystallization kinetics and nonisothermal cold crystallization kinetics of co-PI based on 3, 3′, 4, 4′- biphenyltetracarboxylic dianhydride (s-BPDA)/1, 3-bis-(4-aminophenoxy) benzene (TPER)/4, 4′-oxydianiline(4, 4′-ODA), and TPER PI (s-BPDA/TPER) have been investigated. Avrami equation was used to analyze isothermal melt crystallization progress of TPER PI and co-PI, primary crystallization processes was found to be changed as the introduction of 4, 4′-ODA. Total activation energy ΔE for TPER PI and co-PI were found to be -404 and -86 kJ mol^-1 by Arrhenius equation. Jeziorny's analysis, Ozawa's analysis, and Mo's approach were used to investigate nonisothermal cold crystallization progress of TPER PI and co-PI. Activation energy ΔE _non for TPER PI and co-PI were found to be 247 and 193 kJ mol ^-1 by Kissinger equation. The result indicated that co-PI exhibited lower crystallization rate than TPER PI when isothermally crystallized from melt, but higher crystallization rate under cold nonisothermal crystallization progress. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013