The Cationic Copolymerization of Styrene and p-Brornostyrene in Liquid Sulfur Dioxide

Abstract 1) The cationic copolymerization of styrene and p-bromostyrene in liquid sulfur dioxide using boron trifluoride etherate as a catalyst has been carried out; the monomer reactivity ratios (MRR) have been found to be r1=0.8 and r2=0.4. The MRR value was independent of the temperature and of the quantity of the catalyst in the copolymerization. 2) The effect of added solvents in liquid sulfur dioxide has also been examined. However, the MRR’s have been little affected by the added solvents, the rates of the copolymerization have largely been depressed, and the rates were not dependent on the dielectric constants of the added solvents, the rate in pure liquid sulfur dioxide being the fastest. 3) The same cationic copolymerization has been conducted in benzene, carbon tetrachloride, nitrobenzene and ethylene dichloride. The MRR’s were almost equal in all (r1=1.8 and r2=0.3).