超支化含苯基聚硅氧烷亲二氧化碳特性及其分子模拟

Carbon dioxide-philic properties of hyperbranched phenyl-containing polysiloxane with molecular simulation

摘要:

通过水解缩聚法制备含有不同苯基含量的超支化聚硅氧烷，探究苯基的引入对超支化聚合物在CO2中溶解性能的影响。浊点压力测试得出苯基的引入在超支化结构中对聚合物在CO2中的溶解度影响不大，超支化聚合物中苯基含量的增加没有导致浊点压力的明显升高，有望实现作为CO2增稠剂兼具较好的溶解度和增稠性能。分子模拟计算分析了超支化聚硅氧烷和直链聚硅氧烷与CO2分子间的相互作用以及超支化聚硅氧烷分子间的相互作用，发现含苯基的超支化聚硅氧烷具有更低的内聚能密度（CED）和溶解度参数（δ），表现出更弱的聚合物分子间相互作用，有利于超支化有机硅氧烷在CO2体系中的溶解。

Abstract:

Hyperbranched polysiloxanes with different phenyl content were prepared by hydrolytic polycondensation. The effect of the introduction of phenyl on the solubility of hyperbranched polymers in CO2 was investigated. The cloud point pressure test shows that the introduction of phenyl group has little effect on the solubility of the polymer with hyperbranched structure in CO2. The increase in the content of phenyl in the hyperbranched polymer does not cause a significant increase in the cloud point pressure, which is expected to achieve good solubility and thickening performance as a CO2 thickener. The interactions between hyperbranched polysiloxanes and linear polysiloxanes with CO2 molecules and the interactions between hyperbranched polysiloxanes were calculated and analyzed through molecular simulation, and found that phenyl-containing hyperbranched polysiloxanes possess lower CED and δ, shows a weaker intermolecular polymer interaction, which is beneficial to the dissolution of hyperbranched polysiloxane in CO2.