Nucleation effect of aliphatic polycarbonate in its blends with poly(ethylene terephthalate)

Abstract

Aliphatic polycarbonate (PDCM) was synthesized from dimethyl carbonate and 1,4-cyclohexanedimethanol via melting polymerization in this study. The molecular weight of PDCM was determined by gel permeation chromatography (GPC) to be ca. 49,900. The crystallization behavior and crystallinity of polyethylene terephthalate (PET) were significantly modified by adding 0.3–5.0 wt% PDCM, which was confirmed by differential scanning calorimetry (DSC), photomicrography with a heating stage and SAXS analysis. In nonisothermal crystallization kinetics analysis, the reciprocal of half-time crystallization (i.e., G parameter) for the 1.0 wt% PDCM/PET blends is 3.5 times greater than that of pristine PET at a cooling rate of 10 °C/min. Observation via polarized optical microscopy showed that the spherulites size of PET was condensed by PDCM. In addition, the fold surface energy (σe) decreased with the presence of PDCM. According to the results of dynamic mechanical analysis (DMA) examination, the mechanical strength of 1.0 wt% PDCM/PET thin film was enhanced as the transparency still maintained above 85%, which illustrated the transparent thin film has better thermal stability and has high potential to be used such as in the electronic appliances.