聚合物固载化聚乙二醇季胺盐型相转移催化剂的结构与催化活性

The gelatinous and macroporous phase transfer catalysts with multiple active centers were synthesized by means of quarterisation of PEG tertiary amine and chloromethylated St DVB copolymer. They were examined as phase transfer catalysts in the reaction of n C 8H 17 Br with solid NaI. The experimental results showed that the reaction rate was first order with respect to the concentration of n C 8H 17 Br. The effects of catalyst structure on the catalytic activity were also investigated. The observed reaction rate constant ( k obsd ) increased as the degree of cross linking of polymer decreased. Macroporous catalysts showed a higher activity (2～2 5 times) than that of microporous catalysts with the same degree of cross linking of polymer, particle size and amount of supported PEG. Molecular weight of PEG also showed much influence on k obsd . As molecular weight of PEG rose properly, the catalysts showed a higher activity. The results were discussed from the aspect of triphase catalysis reaction mechanism.

Structure and Catalytic Activity of Polymer-Supported Polyethylene Glycol and Onium Phase Transfer Catalyst

The gelatinous and macroporous phase-transfer c atalysts with multiple active centers were synthesized by means of quarterisatio n of PEG tertiary amine and chloromethylated St-DVB copolymer. They were examin ed as phase-transfer catalysts in the reaction of n-C8H17Br with s olid NaI. The experimental results showed that the reaction rate was first-orde r with respect to the concentration of n-C8H17Br. The effects of ca talyst structure on the catalytic activity were also investigated. The observed reaction rate constant (kobsd) increased as the degree of cross-linki ng of polymer decreased. Macroporous catalysts showed a higher activity (2～2.5 times) than that of microporous catalysts with the same degree of cross-linkin g of polymer, particle size and amount of supported PEG. Molecular weight of PEG also showed much influence on kobsd. As molecular weight of PEG rose properly, the catalysts showed a higher activity. The results were discussed fro m the aspect of triphase catalysis reaction mechanism.