聚乳酸的溶液结晶行为

THE CRYSTALLIZATION BEHAVIOR OF CRYSTALLINE POLY(L-LACTIDE) PREPARED BY SOLUTION CRYSTALLIZATION

采用DSC和XRD方法研究从不同浓度对二甲苯溶液中结晶的聚乳酸的结晶行为。结果表明,从稀溶液中得到的聚乳酸具有高的结晶度,高的非等温结晶温度和快的结晶速度。

The macromolecular chain conformation in solution changes with the solvent and temperature, which will affect the formation of crystalline structure in the subsequent crystallization process. The crystallization behavior of poly （L-lactide） samples prepared from solutions with various concentrations was studied by differential scanning calorimetric and X-ray diffraction. It is found that the sample recovered from dilute solution exhibits the higher crystallinity, higher non-isothermal crystallization temperature and faster crystallization rate. The condensation process of polymer chain in dilute solutions has influence on the crystallization of polymer in the solid state. It results in the acceleration of melt crystallization rate and the rise of nonisothermal crystallization temperature of PLLA recovered from dilute solution.