Controlled synthesis of CO_2-diol from renewable starter by reducing acid value through preactivation approach  

作　　者：Shunjie Liu Yusheng Qin Hongchen Guo Xianhong Wang Fosong Wang 

机构地区：[1]University of Chinese Academy of Sciences,Beijing 100049,China [2]Key Laboratory of Polymer Ecomaterials,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China

出　　处：《Science China Chemistry》2016年第11期1369-1375,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(51321062,21134002)

摘　　要：Synthesis of polyols from carbon dioxide（CO2） is attractive from the viewpoint of sustainable development of polyurethane industry;it is also interesting to adjust the structure of the CO2-polyols for versatile requirement of polyurethane.However,when renewable malonic acid was used as a starter,the copolymerization reaction of CO2 and propylene oxide（PO） was uncontrollable,since it proceeded slowly（13 h） and produced 40.4 wt%of byproduct propylene carbonate（PC） with a low productivity of 0.34kg/g.A careful analysis disclosed that the acid value of the copolymerization medium was the key factor for controlling the copolymerization reaction.Therefore,a preactivation approach was developed to dramatically reduce the acid value to 0.6mg（KOH）/gby homopolymerization of PO into oligo-ether-diol under the initiation of malonic acid,which ensured the controllable copolymerization,where the copolymerization time could be shortened by 77%from 13 to 3 h,the PC content was reduced by 76%from 40.4 wt%to 9.4 wt%,and the productivity increased by 61%from 0.34 to 0.55 kg/g.Moreover,by means of preactivation approach,the molecular weight as well as the carbonate unit content in the CO2-diol was also controllable.Synthesis of polyols from carbon dioxide（CO_2） is attractive from the viewpoint of sustainable development of polyurethane industry;it is also interesting to adjust the structure of the CO_2-polyols for versatile requirement of polyurethane.However,when renewable malonic acid was used as a starter,the copolymerization reaction of CO_2 and propylene oxide（PO） was uncontrollable,since it proceeded slowly（13 h） and produced 40.4 wt%of byproduct propylene carbonate（PC） with a low productivity of 0.34kg/g.A careful analysis disclosed that the acid value of the copolymerization medium was the key factor for controlling the copolymerization reaction.Therefore,a preactivation approach was developed to dramatically reduce the acid value to ~0.6mg（KOH）/gby homopolymerization of PO into oligo-ether-diol under the initiation of malonic acid,which ensured the controllable copolymerization,where the copolymerization time could be shortened by 77%from 13 to 3 h,the PC content was reduced by 76%from 40.4 wt%to 9.4 wt%,and the productivity increased by 61%from 0.34 to 0.55 kg/g.Moreover,by means of preactivation approach,the molecular weight as well as the carbonate unit content in the CO_2-diol was also controllable.

关 键 词：CO_2-polyols renewable starter acid value controllable copolymerization preactivation approach 

分 类 号：O631.5[理学—高分子化学]