Yang Jia-Liang, Wang Ying, Cao Xiao-Han, Zhang Cheng-Jian, Chen Zheng, Zhang Xing-Hong
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China.
Macromol Rapid Commun. 2021 Feb;42(3):e2000472. doi: 10.1002/marc.202000472. Epub 2020 Nov 18.
This work describes the first example of semicrystalline poly(thiocarbonate)s from carbon disulfide (CS ) and ethylene oxide (EO), two mass producible low-cost monomers. Lewis acid/base pairs (LPs) exhibit high activity (EO conversion up to >99%, 8 h) in catalyzing the copolymerization under low Lewis pair/monomer ratio of 1:1500. Oxygen-sulfur exchange reaction (O-S ER) during the copolymerization of CS and EO, the generation and mutual copolymerization with COS, CO , and episulfide, is harnessed to introduce crystallizable segments [SC(O)O and SC(S)S] in the copolymer. The type of Lewis base is found to have a great impact on the chain microstructure and the crystalline properties. The formed copolymers with melting point from 117.7 to 245.3 °C are obtained. The maximum crystallinity is estimated to be 78% based on the powder wide-angle X-ray diffraction pattern. This work provides a general method to prepare semicrystalline sulfur-containing polymers.
这项工作描述了由二硫化碳（CS₂）和环氧乙烷（EO）这两种可大规模生产的低成本单体合成半结晶聚（硫代碳酸酯）的首个实例。路易斯酸/碱对（LPs）在低路易斯对/单体比例为1:1500的条件下催化共聚反应时表现出高活性（环氧乙烷转化率高达>99%，8小时）。在二硫化碳和环氧乙烷的共聚过程中利用氧-硫交换反应（O-S ER）以及与COS、CO₂和环硫乙烷的生成及相互共聚反应，在共聚物中引入可结晶链段[SC(O)O和SC(S)S]。发现路易斯碱的类型对链微观结构和结晶性能有很大影响。得到了熔点在117.7至245.3℃之间的共聚物。基于粉末广角X射线衍射图谱估计最大结晶度为78%。这项工作提供了一种制备半结晶含硫聚合物的通用方法。
