公开(公告)号：US09475790B2

公开(公告)日：2016-10-25

申请号：US14534151

申请日：2014-11-05

申请人： Xiaogan Esun New Material Co., Ltd.

发明人： Yihu Yang ,  Jie Xu

IPC分类号： C07D319/00 ,  C07D319/12 ,  C08J11/12 ,  C08J11/16

CPC分类号： C07D319/12 ,  C08J11/12 ,  C08J11/16 ,  C08J2367/04 ,  Y02W30/703 ,  Y02W30/705

摘要： A method for preparing lactide from recovered polylactic acid, the method including the following steps: A. pretreating the recovered polylactic acid; B. extruding the treated polylactic acid from a twin screw extruder to yield a polylactic acid melt, and introducing the polylactic acid melt to a pre-depolymerization kettle; C. carrying out a chain scission reaction to break molecular chains in the polylactic acid melt and to decrease the number-average molecular weight of the polylactic acid melt to below 5000; D. conducting depolymerization reaction to yield a crude lactide; and E. purifying the crude lactide and crystallizing the purified lactide.

摘要翻译： 从回收聚乳酸制备丙交酯的方法，其方法包括以下步骤：A.预处理回收的聚乳酸; B.从双螺杆挤出机挤出经处理的聚乳酸，得到聚乳酸熔体，并将聚乳酸熔体引入预解聚釜中; C.进行断链反应以破坏聚乳酸熔体中的分子链，并将聚乳酸熔体的数均分子量降至5000以下; D.进行解聚反应，得到粗丙交酯; 和E.纯化粗丙交酯并使纯化的丙交酯结晶。