Controlled synthesis of CO₂-diol from renewable starter by reducing acid value through preactivation approach

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• 作者：Shunjie Liu ; Yusheng Qin ; Hongchen Guo ; Xianhong Wang…
• 关键词：CO2 ; polyols ; renewable starter ; acid value ; controllable copolymerization ; preactivation approach
• 刊名：SCIENCE CHINA Chemistry
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：59
• 期：11
• 页码：1369-1375
• 全文大小：900 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Chinese Library of Science
  Chemistry
  
• 出版者：Science China Press, co-published with Springer
• ISSN：1869-1870
• 卷排序：59

文摘

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 0.34 kg/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 ~0.6 mg(KOH)/g by 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.