CID 53628100 → Benzene, ethenyl-, polymer with 1,3-butadiene

A 3-arm star styrene/butadiene block copolymer was synthesized using standard high vacuum techniques, M. Morton et al., J. Rubber Chem. and Technol., 48, 359 (1975). An example of the general polymerization procedure is as follows: A 1000 ml all-glass reactor was attached to the vacuum line and flamed with a hand torch to remove surface moisture. Approximately 500 ml of benzene was distilled into the apparatus and magnetic stirring was commenced. An ampule containing 0.0165 mol of sec-butyl lithium in benzene was released into the vessel through a breakseal. Styryl oligomers of an average length of four (4) units were then formed by opening an ampule containing 0.0655 mol of styrene monomer. The contents of the reactor changed in color from a clear water-white to a deep orange over the course of 24 hours at 25° C. To prepare for the addition of butadiene and to increase the amount of 1,2 enchainment in the polybutadiene segment, 0.717 mol of triethyl amine (TEA) was distilled into the reactor after being stirred over n-butyl lithium; the molar ratio of TEA/ living chain end was 45:1. The reaction mass changed to a dark red color during the step. An ampule containing 1.70 mol of 1,3 butadiene was then slowly released into the vessel, which was held at 10° C. by means of a constant temperature bath, over the course of five (5) hours. The viscosity of the mixture increased markedly during this period, and the color faded to a pale yellow. After warming the viscous solution to room temperature and stirring for an additional 48 hours, 0.0049 mol of methyl trichlorosilane in benzene solution was added from an ampule to couple the polymer chains and form the three-arm star polymer. The linking reaction was allowed to proceed at 40° C. for 72 hours.

1. customA 1000 ml all-glass reactor was attached to the vacuum line
2. temperatureflamed with a hand torch
3. customto remove surface moisture
4. distillationApproximately 500 ml of benzene was distilled into the apparatus

ORD record

ord-1f8f3bcc3cb441fcbe245d7443f107a4

Source dataset

uspto-grants-1991_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05039752