Patents by Inventor Yihu YANG

Yihu YANG has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for preparing refined lactide from recovered polylactic acid
    Patent number: 9475790
    Abstract: 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.
    Type: Grant
    Filed: November 5, 2014
    Date of Patent: October 25, 2016
    Assignee: XIAOGAN ESUN MATERIAL CO., LTD.
    Inventors: Yihu Yang, Jie Xu
  • METHOD FOR PREPARING REFINED LACTIDE FROM RECOVERED POLYLACTIC ACID
    Publication number: 20150065732
    Abstract: 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 polylacitc acid from a twin screw extruder to yield a polylacitc acid melt, and introducing the polylacitc 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.
    Type: Application
    Filed: November 5, 2014
    Publication date: March 5, 2015
    Inventors: Yihu YANG, Jie XU