Abstract—

Carbon dioxide is a well-known green solvent, and can be used instead of some organic solvent to prepare the polymer products. On the basis of its poor solubility, dispersion polymerization can be adopted to produce the polymer products in industry. Thus, low price, easily available stabilizers with good stabilization effect will be a must. In this paper, we are committed to designing and synthesizing stabilizers with these characteristics. Firstly, thiol ethanol is used as the chain-transfer agent to control the copolymerization of vinyl acetate/vinyl propionate, and the homopolymers or copolymers with the hydroxyl group at the chain terminal are obtained. These homopolymers or copolymers are then functionalized to prepare the stabilizers with methacrylate groups. The results indicate that these stabilizers can effectively control the dispersion polymerization of methyl methacrylate in supercritical carbon dioxide. The proportion of structural units in the copolymer and the concentration of stabilizer or initiator obviously affect the conversion percentage of methyl methacrylate and the molecular weight of polymers. The maximum conversion percentage of methyl methacrylate and the molecular weight of poly(methyl methacrylate) can reach 93%, and 56000 Da, respectively. SEM images show that most of the samples are free-flowing powders with a spherical structure.

中文翻译：

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超临界二氧化碳中聚乙酸乙烯酯/丙酸乙烯酯共聚物作为稳定剂的甲基丙烯酸甲酯分散聚合

摘要-

二氧化碳是众所周知的绿色溶剂，可以代替某些有机溶剂制备聚合物产品。由于其溶解性差，工业上可采用分散聚合来生产聚合物产品。因此，价格低廉、易得、稳定效果好的稳定剂将是必须的。在本文中，我们致力于设计和合成具有这些特性的稳定剂。首先以硫醇乙醇为链转移剂，控制乙酸乙烯酯/丙酸乙烯酯的共聚，得到链端带有羟基的均聚物或共聚物。然后将这些均聚物或共聚物官能化以制备具有甲基丙烯酸酯基团的稳定剂。结果表明，这些稳定剂可以有效控制甲基丙烯酸甲酯在超临界二氧化碳中的分散聚合。共聚物中结构单元的比例以及稳定剂或引发剂的浓度明显影响甲基丙烯酸甲酯的转化率和聚合物的分子量。甲基丙烯酸甲酯的最大转化率和聚甲基丙烯酸甲酯的分子量分别可达93％和56000Da。SEM 图像显示大多数样品是具有球形结构的自由流动粉末。共聚物中结构单元的比例以及稳定剂或引发剂的浓度明显影响甲基丙烯酸甲酯的转化率和聚合物的分子量。甲基丙烯酸甲酯的最大转化率和聚甲基丙烯酸甲酯的分子量分别可达93％和56000Da。SEM 图像显示大多数样品是具有球形结构的自由流动粉末。共聚物中结构单元的比例以及稳定剂或引发剂的浓度明显影响甲基丙烯酸甲酯的转化率和聚合物的分子量。甲基丙烯酸甲酯的最大转化率和聚甲基丙烯酸甲酯的分子量分别可达93％和56000Da。SEM 图像显示大多数样品是具有球形结构的自由流动粉末。