Molecular weight dependence of the crystallization of the polycarbonate induced by supercritical CO2

• Solubility of CO2 was independent of the molecular weight (MW) of PC.
• Crystallinity and crystallization rate decreased with increasing MW..
• Crystallization rate was properly correlated including MW dependence.

The effect of molecular weight on the crystallinity and crystallization rate of polycarbonate (PC) in the presence of supercritical CO2 was studied at temperatures from 75 to 175 °C and at pressures up to 20 MPa. Crystallinities decreased ca. 0.05 and maximum crystallization rates decreased ca. 50% with an increase in the weight-average molecular weights of the PC from 19.2 to 29.8 kg/mol. Moreover, the maximum crystallization rates were properly correlated with the average absolute error of 30% by considering the changes in the glass transition temperature and melting temperature caused by the plasticization effect of dissolved CO2.

Figure optionsDownload as PowerPoint slide