结晶温度对左旋聚乳酸的晶体改性和晶体形貌的影响  

Effect of crystallization temperature on crystal modifications and crystallization morphology of poly(L-lactic acid)

作　　者：徐阳[1] 孙志丹[2] 陈晓浪[1] 郭刚[3] 张志斌[2] 胡书春[1] 

机构地区：[1]西南交通大学材料科学与工程学院,材料先进技术教育部重点实验室,四川成都610031 [2]西南交通大学生命科学与工程学院,四川成都610031 [3]四川大学华西医学院生物治疗国家重点实验室,四川成都610041

出　　处：《功能材料》2012年第16期2138-2141,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51003088);高等学校博士学科点专项基金资助项目(20100184120006);国家科技支撑计划资助项目(2007BAB08B05);中央高校基本科研业务费专项资金资助项目(SWJTU12CX009;SWJTU11ZT10);西南交通大学高层次人才"竢实之星"资助项目(2011);西南交通大学高层次人才"希望之星"资助项目(2008)

摘　　要：以左旋聚乳酸(PLLA)为原料,制备了无定型PLLA膜及无定型PLLA在不同温度下等温结晶的样品。利用红外光谱(FT-IR)、X射线衍射(XRD)和偏光显微镜(POM)分析了结晶温度的改变对PLLA样品的晶体改性及晶体形貌的影响。研究结果表明,结晶温度的改变对PLLA样品的晶体结构、晶型转变及晶粒形貌特征产生了较大的影响。当结晶温度低于100℃时,PLLA主要以无序的α'-晶型存在;随着结晶温度的增加,PLLA的晶体结构和晶型开始转变,当结晶温度超过120℃后,PLLA主要以α-晶型的形式存在;而当结晶温度在100～120℃范围内,则形成的是α'-与α-晶型PLLA的混合形式存在。另一方面,POM照片测试结果表明,随着结晶温度的升高,PLLA的晶体形貌发生了改变,晶粒尺寸随温度的增加而增加,结晶速度增加,晶粒数量减少,PLLA晶体由α'-向α-晶型发生了转变。In this work, amorphous PLLA films and crystalline PLLA samples were prepared at different crys- tallization temperatures （80-160℃）. The crystal modifications and crystallization morphologies of PLLA sam- ples were studied by Infrared spectroscopy （FT-IR）, X-ray diffraction （XRD）, and polarized optical micro- graphs （POM）. The results demonstrated that the change of crystallization temperature has a great effect on the crystal structure, phase transition, and crystallization morphology of PLLA. At crystallization temperature 〈100℃, disorder aP-crystal is mainly produced for the crystal structure of PLLA samples; however, at crystal- lization temperature ≥ 120℃, the order a-crystals PLLA are mainly proposed; whe the crystallization tempera- ture is between 100 to 120℃, both a- and a-forms coexist. Besides, the crystal morphologies of PLLA samples were illustrated, and it was found that the crystal size increases and the number of spherulite decreases with in- creasing the crystallization temperature. It was found that the disorder-to-order （a-to a-crystalline form） tran- sition occures with increasing crystallization temperature above 120℃.

关 键 词：左旋聚乳酸 结晶温度 晶体改性 晶体形貌 

分 类 号：TQ317.3[化学工程—高聚物工业]