| Abstract: | The hydroxyl group content in 1-chlorobutadiene–butadiene rubber prepared by emulsion polymerization (CB–BR) was determined by UV spectroscopy. CB–BR was allowed to react with phenyl isocyanate at room temperature, and the resulting N-phenyl carbamate was assayed by UV measurement. The present method allowed the determination of a very small amount of hydroxyl groups contained in a high molecular weight hydrocarbon polymer. The hydroxyl group content in the hydroxyl-terminated liquid polybutadiene was also determined. The value agreed closely with that obtained by the usual titration method. Hydroxyl groups in CB–BR are presumed to be produced by the hydrolysis of the active chlorine contained in CB–BR. This hydrolysis is dependent on the work-up conditions of CB–BR, and the quantitative results were discussed with reference to the microstructure of the 1-chlorobutadiene unit in CB–BR. |
