Crystallization kinetics of poly(L‐lactide) in contact with pressurized CO2
Tóm tắt
The effect of CO2 on the isothermal crystallization kinetics of poly(L‐lactide), PLLA, was investigated using a high‐pressure differential scanning calorimeter (DSC), which can perform calorimetric measurements while keeping the sample polymer in contact with pressurized CO2. It was found that the crystallization rate followed the Avrami equation. However, the crystallization kinetic constant was changed depending upon the crystallization temperature and concentration of CO2 dissolved in the PLLA. The crystallization rate was accelerated by CO2 at the temperature in the crystal‐growth rate controlled region (self‐diffusion controlled region), and depressed in the nucleation‐controlled region. CO2 has also decreased the glass transition temperature,
Từ khóa
Tài liệu tham khảo
R.Gendron “Applied Rheology for the Extrusion of Thermoplastic Foams;”Proceedings of Foams'99(1999).
Operating Instruction for the DSC High Pressure Cell Perkin‐Elmer.