Synthesis of Poly(1,4-cyclohexanedimethyl-1,4-cyclohexanedicarboxylate) as the Matrix Resin for Transparent Composites

PCCD polymers were prepared by melt polycondensation of 1,4-cyclohexanedimethanol (CHDM) and 1,4-cyclohexanedicarboxylic acid (CHDA) in the presence of titanium tetrabutoxide (TBT) as catalyst in a successive two-step polymerization. In the first stage, the effect of esterification temperature and stirring rate on reaction degree were investigated. The impact of reaction temperature on reaction degree was more obvious than that of stirring rate. The optimal esterification temperature and optimal stirring rate was 220 °C and 150 r/min respectively. In the second stage, the reaction conditions such as molar ratios of CHDM to CHDA and polymerization temperature were controlled for the optimum results. M _n of PCCD polymers increased with increasing initial molar ratio of CHDM to CHDA firstly, got its maximum when initial molar ratio reached 1.004:1, and then decreased when initial molar ratio exceeded 1.004:1. The polymerization temperature of 275 °C can lead to high molecular weight PCCD polymers (Mn>30,000). Finally PCCD/glass composites were studied, and it was shown that the composites maintain high transmittance and low haze like those of pure PCCD but possess better mechanical and thermal properties.