Dioxolenium salt, polystyrene

Polymerization of THF by Polystyrene Dioxolenium Salt. Polystyrene with terminal dioxolenium salt groups was prepared by the... 

Preparation of Macromolecular Dioxolenium Salts. Living polystyrene prepared by the polymerization of styrene in THF with a-methylstyrene tetramer dianion reacted with a 2.1-molar amount of ethylene oxide for three hours at room temperature a 6.6-molar amount of adipoyl chloride was added, and the mixture was stirred for 20 horns a 20-molar amount of ethylenebromohydrin was added. This mixture was stirred for 44 hours. The bromoethylated polystyrene was precipitated in excess methanol and freeze-dried from benzene in a vacuum system. A 1-nitropropane solution of polystyrene dioxolenium salt was prepared by reaction of bromoethylated polystyrene with silver perchlorate in 1-nitropropane. Silver bromide was removed from the reaction mixture by filtration. Molecular weight of the product was measured by a vapor-pressure osmometer it was 1910 for living polystyrene and 5190 for the bromoethylated polystyrene. Bromine analysis of the bromoethylated polystyrene showed 67.9% of the calculated value. 

The polymerization of THF with polystyrene dioxolenium salt was carried out in 1-nitropropane at 0°C. Table I shows the increase in molecular weight with conversion. The resulting copolymer was a... 

Grafting with a well defined number of active sites has also been performed. It was established earlier that 2-phenyl-1,3-dioxolan-2-ylium salts initiate the polymerization of THF by direct addition and proceed with opening of the C-4/0-3 bond in the dioxolenium cation 151). Thus, Okada et al. have prepared dioxolenium salts coupled to phenyl rings in polystyrene 152) ... 

Block or graft copolymem can be obtained by cationic polymerization of THF with macromolecular initiators. The recommended groups for the initiation are the dioxolenium cation, the acyl cation and the super acid ester, each of which can be introduced into the backbone polymer by reaction with silver salts of strong acids. Introduction of the dioxolenium group into polystyrene was carried out by the following route32 ... 

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