一种熔融缩聚-固相聚合制备高分子量聚L-乳酸的方法
申请公布号:CN1594393A
申请号:CN200410041426.8
申请日期:2004.07.15
申请公布日期:2005.03.16
发明人:周正发;徐卫兵;左春荣
分类号:C08G63/06;C08G63/08
主分类号:C08G63/06
代理人:何梅生;吴启运
地址:230009安徽省合肥市屯溪路193号
摘要:一种熔融缩聚-固相聚合制备高分子量聚L-乳酸的方法,其特征是按如下步骤进行a.熔融缩聚:将原料L-乳酸脱水后,在催化剂作用下,熔融缩聚获得L-乳酸预聚物;b.固相聚合:将L-乳酸预聚物等温结晶后粉碎,在作为吸水剂的分子筛存在下固相聚合,制得高分子量的聚L-乳酸。本发明选择售价较低的L-乳酸为原料,通过直接熔融缩聚-固相聚合的方法,制备高分子量的聚L-乳酸。可以避免L-乳酸溶液缩聚过程中溶剂回收以及产品中溶剂残留的问题。也可以避开丙交酯开环聚合制备聚L-乳酸过程中丙交酯的合成与精制等问题。
主权项:1、一种熔融缩聚—固相聚合制备高分子量聚L-乳酸的方法,其特征是按如下步骤进行:a、熔融缩聚:将原料L-乳酸脱水后,在催化剂作用下,熔融缩聚获得L-乳酸预聚物;b、固相聚合:将上述L-乳酸预聚物等温结晶后粉碎,在作为吸水剂的分子筛存在下固相聚合,制得高分子量的聚L-乳酸。
PROCESS FOR THE VACUUM-ASSISTED RESIN IMPREGNATION OF REINFORCING MATERIAL WITH EQUALIZED PRESSURE
SANDBOXING APPLICATIONS IN A PRIVATE NETWORK USING A PUBLIC-NETWORK INFRASTRUCTURE
SAFE INFORMATION INTERCHANGE BETWEEN A USER OF A TERMINAL AND A SIM APPLICATION TOOLKIT VIA WAP
HYBRID ELECTRIC POWER GENERATOR AND METHOD FOR GENERATING ELECTRIC POWER
METHOD AND SYSTEM OF PREVENTING CORROSION OF CONDUCTIVE STRUCTURES
METHOD FOR UTILIZING GAS RESERVES WITH LOW METHANE CONCENTRATIONS FOR FUELING GAS TURBINES
CAN LID CLOSURE AND METHOD OF JOINING A CAN LID CLOSURE TO A CAN BODY
ION IMPLANTATION ION SOURCE, SYSTEM AND METHOD
A PROCESS FOR HYDROGENATING AROMATIC POLYMERS
ANTIBACTERIAL HETEROBICYCLIC SUBSTITUTED PHENYL OXAZOLIDINONES