Benzene → Styrene t-butylstyrene

Beteiligte Stoffe

Reaktionsschritte

Under anaerobic and anhydrous conditions 400 ml of purified benzene is charged to a polymerization vessel followed by 0.53 milliequivalents of n-butyllithium in heptane. t-Butylstyrene (9.0 g, 0.056 mole) is added at about 30° C., and the resultant solution is stirred 15-30 minutes at 30°-60° C. Six more monomer additions are made as follows: styrene (18.0 g, 0.173 mole), t-butylstyrene (9.0 g), styrene (18.0 g), t-butylstyrene (9.0 g), styrene (18.0 g), and t-butylstyrene (9.0 g). Between additions the solution is permitted to stir for 15-30 minutes at 30°-60° C. The polymerization solution is then inactivated by the addition of a small quantity of methanol, and the seven block copolymer is isolated by precipitation with methanol in a Waring blender. The precipitated block copolymer is thoroughly washed with methanol and vacuum oven dried at 80° C. for 24 hours. A quantitative yield (90 g) of block copolymer is obtained. Gel permeation chromatography shows the copolymer to possess a narrow molecular weight distribution. A molded film of the block copolymer is clear and transparent. The calculated degree of polymerization of the seven block copolymer is 1400, and the calculated molecular weight is 170,000.

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