Liquid-liquid (L-L) de-mixing and vitrification of solutions of either crystallizable poly(L-lactic acid) (PLLA) or non-crystallizable poly(D/L-lactic acid) (PDLLA) with 50 m% N, N-diethyl-3-methylbenzamide (DEET) were analyzed by calorimetry and cloud-point measurements, which allows drawing conclusions about the effect of polymer stereochemistry on the phase behavior. Regardless of the PLA stereochemistry, vitrification of the solutions on fast cooling, hindering crystallization of PLLA, occurred below −20 °C and suppressed prior L-L de-mixing. The experimental results prove that crystallization in samples containing crystallizable PLLA, observed at around 55 °C on slow cooling, is not preceded by L-L de-mixing.

中文翻译：

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不同立体化学和DEET的PLA溶液中液-液解混，结晶和玻璃化转变之间的竞争

液-液（LL）的去混合并用50 M％任一结晶的聚（L-乳酸）（PLLA）或非晶性聚（d / L-乳酸）（PDLLA）的解决方案的玻璃化N，N- -通过量热法和浊点测量法分析了二乙基-3-甲基苯甲酰胺（DEET），这可以得出有关聚合物立体化学对相行为的影响的结论。不管PLA的立体化学如何，快速冷却后溶液的玻璃化都会阻碍PLLA的结晶，发生在低于-20°C的温度下，并且会抑制LL的预混合。实验结果证明，在缓慢冷却下于约55°C观察到的含有可结晶PLLA的样品中的结晶不会在进行LL分离之前发生。