乳酸构型对直接合成聚乳酸-聚乙二醇的影响  

Influence of lactic acid configuration on synthesis of polylactic acid-polyethylene glycol via direct melt copolymerization

作　　者：汪朝阳[1,2] 赵耀明[1] 王方[1,3] 

机构地区：[1]华南理工大学材料学院,广东广州510640 [2]华南师范大学化学系 [3]震德塑料机械厂有限公司技术中心

出　　处：《合成树脂及塑料》2005年第3期10-13,共4页China Synthetic Resin and Plastics

基　　金：广东省自然科学基金(020885)。

摘　　要：直接以左旋乳酸(L-LA)单体和数均分子量为1000的聚乙二醇(PEG)为原料,通过直接熔融共聚法,合成了聚乳酸-聚乙二醇(L-PLEG)适宜的工艺条件为：以SnO为催化剂[m(SnO)/m(L-LA)为0.005],在165℃、70 Pa下反应10h。用特性黏数([η])、凝胶渗透色谱(GPC)、差示扫描量热法、X射线衍射、接触角测试等手段对其进行系统表征,L-PLEG的[η]最高可达0.2056dL/g：GPC测定其重均分子量(M_w)为15600；相对分子质量分布为1.30。与以外消旋乳酸(D,L-LA)与PEG熔融共聚合成的D,L-PLEG相比,[η]和M_w较小,而玻璃化转变温度、熔融温度、结晶度较高。A kind of biodegradable material poly(L-lactic acid)-polyethylene glycol (L-PLEG) was synthesized directly via melt polycondensation process with taking L-lactic acid (L-LA) and polyethylene glycol (PEG) having number average relative molecular mass (Mn) 1000 as raw materials. The appropriate process conditions involved using SnO as catalyst, the mass ratio of SnO to L-LA being 0.005, reaction temperature 165°C, reaction pressure 70 Pa and reaction time 10 h. The copolymer L-PLEG was systematically characterized by intrinsic viscosity index ([η]), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), X-ray diffraction pattern and contact angle measurement. The data indicate that L-PLEG has intrinsic viscosity [η] up to 0.2056 dL/g, weight average molecular mass 15600 (Mw) and relative molecular mass distribution 1.30. The L-PLEG has a lower [η] and Mw, but higher glass transition temperature, melting temperature and crystallinity, compared with poly(D,L-lactic acid)-polyethylene glycol (D,L-PLEG).

关 键 词：聚乳酸 直接合成 聚乙二醇(PEG) 相对分子质量分布 差示扫描量热法 玻璃化转变温度 构型 凝胶渗透色谱 数均分子量 X射线衍射 重均分子量 工艺条件 特性黏数 共聚合成 熔融温度 共聚法 催化剂 SnO 接触角 GPC 外消旋 结晶度 

分 类 号：TQ325.9[化学工程—合成树脂塑料工业]