反应详情

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.

1. washThe precipitated block copolymer is thoroughly washed with methanol and vacuum oven
2. customdried at 80°C. for 24 hours
3. customA quantitative yield (90 g) of block copolymer is obtained
4. customThe calculated degree of polymerization of the seven block copolymer