Cationic Polymerizations in Supercritical Carbon Dioxide

碳阳离子聚合广泛用于大规模聚合。 批量工业过程（例如，丁基橡胶和 异丁烯基工业）。 这些聚合是 通常在有毒的氯化烃中进行 溶剂，其中数千磅最终每年在 大气层 这个项目是一个调查， 可能取代这些污染溶剂与 环境中性，廉价的二氧化碳， 傅-克酸介导的通用溶剂 聚合，并且除此之外，Friedel-Crafts酸 一般来说，催化反应。 第一个具体的推力将是证明， 有毒溶剂可以用超临界碳取代 二氧化物在碳阳离子聚合中， 共聚，并阐明范围和基本原理 这些过程。 随后将进行探索 傅-克酸催化反应，如 烷基化、磺化、乙酰化等。 压力、温度和试剂浓度 将探索超临界二氧化碳。 初始 聚合研究的阶段将涉及共同的 单体（异丁烯、苯乙烯及其衍生物，和 共轭二烯，如异戊二烯），共引发剂，和小的 添加剂（共溶剂、质子阱、电子 供体和盐）。

Carbocationic polymerizations are used extensively in large volume industrial processes (for example, butyl rubbers and isobutylene-based industries). These polymerizations are commonly carried out in toxic chlorinated hydrocarbon solvents, many thousands of pounds of which end up yearly in the atmosphere. This project is an investigation into the possibility of replacing these polluting solvents with the environmentally neutral, inexpensive carbon dioxide as the all-purpose solvents for Friedel-Crafts acids mediated polymerizations, and beyond these, to Friedel-Crafts acid catalyzed reactions in general. The first specific thrust will be the demonstration that the toxic solvents can be replaced with supercritical carbon dioxide in carbocationic polymerizations and copolymerizations, and to elucidate the scope and fundamentals of these processes. This will be followed by explorations into Friedel-Crafts acid catalyzed reactions, such as alkylation, sulfonation, acetylation, etc. The effects of pressure, temperature, and reagent concentrations in supercritical carbon dioxide will be explored. The initial phase of the polymerization studies will concern common monomers (isobutylene, styrene and its derivatives, and conjugated dienes such as isoprene), coinitiators, and small amounts of additives (cosolvents, proton traps, electron donors, and salts).