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以L-乳酸和季戊四醇为原料,采用缩聚法合成了星形结构的聚L-乳酸(SPLLA)。用NMR、GPC、X射线衍射、粘度计等手段对聚合物的结构进行了表征,并证明了支化结构的存在。所合成的SPLLA分子量分布指数DI<1·2,特性粘度、均方根末端距均小于同分子量的线型聚L-乳酸(LPLLA)。反应速度明显快于同催化剂合成LPLLA时的反应速度,有利于合成较高分子量的聚L-乳酸。
Using L-lactic acid and pentaerythritol as raw materials, poly (L-lactic acid) (SPLLA) was synthesized by polycondensation. The structure of the polymer was characterized by means of NMR, GPC, X-ray diffraction and viscometer, and the existence of branched structure was proved. The synthesized SPLLA molecular weight distribution index DI <1.2, intrinsic viscosity, root mean square distance is less than the same molecular weight linear poly L-lactic acid (LPLLA). The reaction speed is obviously faster than the reaction speed when synthesizing LPLLA with the catalyst, which is favorable for synthesizing poly-L-lactic acid with higher molecular weight.