深度冷冻干燥对聚(L-乳酸)结晶性能的影响  

EFFECT OF FREEZE-DRYING FROM PLLA SOLUTIONS WITH VARYING CONCENTRATIONS ON CRYSTALLIZATION OF POLY(L-LACTIDE)

作　　者：郝红[1] 刘荣杰[1] 张粉艳[1] 赵涛[1] 管晓玉[1] 

机构地区：[1]西北大学化工学院,西安710069

出　　处：《离子交换与吸附》2009年第4期313-318,共6页Ion Exchange and Adsorption

基　　金：陕西省13115科技创新工程重大科技专项项目(2007ZDKG-50);陕西省教育厅产业化培育项目资助(08JC04)

摘　　要：采用广角X射线衍射(XRD)和差示扫描量热(DSC)方法研究了深度冷冻干燥对PLLA结晶性能的影响。深度冷冻干燥方法可以改善PLLA的结晶性能。实验结果表明,0.1%、1%、5%和10%PLLA的对二甲苯溶液经过深度冷冻干燥得到PLLA的结晶速度系数(CRC)分别为0.935、0.877、0.826和0.863,高于从0.1%对二甲苯溶液中结晶得到的PLLA的CRC(为0.643)。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. Poly（L-lactide） （PLLA） was freeze-dried from p-xylene solutions with varying concentrations. The recovered samples were characterized by differential scanning calorimetric and X-ray diffraction. It is found that the sample exhibits the higher non-isothermal crystallization temperature and faster crystallization rate. The crystallization rate coefficients （CRC） of PLLA prepared from 0.1% solution is 0.935, which is much higher than that of samples crystallized by solution crystallization. Freezing the PLLA/p-xylene solution in liquid nitrogen seems to create numerous nuclei of solvent which might induce the nucleation of the PLLA solution. After annealing the freeze-dried PLLA, the crystallization will proceed very fast since there are many nuclei in the sample and fewer chain entanglements.

关 键 词：聚(L-乳酸) 结晶性能 深度冷冻干燥 解缠结 

分 类 号：O631[理学—高分子化学]