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以L-乳酸为原料,季戊四醇为支化剂,采用SnCl2·2H2O/TSA复合催化剂合成了星形支化聚L-乳酸,并采用DSC、偏光显微镜研究了星形聚L-乳酸的结晶和熔融行为,探讨了星形聚乳酸的热降解性能。DSC研究结果表明,熔融缩聚制备的星形聚L-乳酸在升温过程中基本观察不到冷结晶峰,只出现一个熔融峰。经过等温结晶处理后的星形聚L-乳酸再次升温时出现双熔融峰,其中低熔融峰的峰值温度(Tm(L))与等温结晶温度的对数值成线性增长关系,而高熔融峰的峰值温度(Tm(H))与等温结晶温度基本无关。
Star-branched poly (L-lactic acid) was synthesized by using L-lactic acid as raw material and pentaerythritol as branching agent. The star-branched poly (L-lactic acid) was synthesized by SnCl2 · 2H2O / TSA composite catalyst. Behavior, discussed the thermal degradation of star polylactic acid. DSC results show that the melting polycondensation prepared star poly-L-lactic acid in the heating process basically observed no cold crystallization peak, only a melting peak. After the isothermal crystallization treatment of star poly-L-lactic acid again when the temperature rise double melting peak, in which the low melting peak temperature (Tm (L)) and the isothermal crystallization temperature logarithmically linear relationship, while the high melting peak The peak temperature (Tm (H)) has little to do with the isothermal crystallization temperature.