Poly(1

4-cyclohexanedimethyl-1

4-cyclohexanedicarboxylate) (PCCD) polymers were prepared by melt polycondensation of 1

4-cyclohexanedimethanol (CHDM) and 1

4-cyclohexanedicarboxylic acid (CHDA). The impact of cis-trans ratio of the incorporated CHDA on the phase and optical properties of PCCD was investigated

and the results indicated that amorphous PCCD with high transmittance can be obtained when the initial cis-CHDA content was no less than 40%. Three kinds of titanic compounds including tetrabutyl titanate (TBT)

tetraisopyl titanate (TPT) and TiO2/SiO2 blend (C-94) were used as catalysts in PCCD polyermerzition

and TBT exhibited the highest activity. The influence of TPT content on molecular weight was then investigated. GPC measurements

1H- and 13C-NMR tests were performed in order to evaluate the impact of the initial CHDM/CHDA molar ratios on PCCDs molecular weight. It was found that the molecular weight increased sharply when CHDM was used in slight excess and then decreased with increase of CHDM/CHDA molar ratio. The excess of CHDM over CHDA used for PCCD preparation must be controlled precisely in order to achieve high molecular weight because CHDM had relatively low volatility according to the NMR spectroscopy. Finally the effects of preparing conditions

such as polymerization time and temperature

were evaluated. Reaction time for obtaining the maximum molecular weight increased with increasing initial molar ratio of CHDM to CHDA. It was shown that the PCCD polyester prepared by the condensation of CHDM and CHDA (molar ratio of 1.04∶1) in the presence of 30mg/kg of TPT

with a residence time more than 120min above 275℃

had a desirably high molecular weight.