Dichlorodimethylsilane → 2-Methylbuta-1,3-diene;styrene

Participants

Reaction Conditions

Reaction Steps

In a pressure resistant reactor, 23.3 kg of cyclohexane, 5.00 millimoles of TMEDA, and 1.90 kg of styrene were added, and while the mixture was stirred at 40° C., 166.7 millimoles of n-butyllithium was added thereto. While the temperature was elevated to 50° C., polymerization was carried out for one hour. The polymerization conversion ratio for styrene was 100%. Subsequently, while the temperature was controlled to be maintained at 50° C. to 60° C., 5.20 kg of isoprene was continuously added to the reactor over one hour. After completion of the addition of isoprene, polymerization was carried out for another one hour. The polymerization conversion ratio for isoprene was 100%. Thereafter, 50.0 millimoles of dimethyldichlorosilane and 12.5 millimoles of tetrachlorosilane were added to the reactor as coupling agents, and a coupling reaction was carried out for 2 hours. Thus, a styrene-isoprene-styrene block copolymer and a branched styrene-isoprene block copolymer were formed. Subsequently, 333.4 millimoles of methanol was added to the reaction liquid which was believed to have a styrene-isoprene block copolymer having an active terminal remaining therein. The resulting mixture was thoroughly mixed, and thereby the active terminal was deactivated. A portion of the reaction liquid thus obtained was taken out, and the same measurements as in Example 1 were made. These values are presented in Table 2. The subsequent operation was carried out in the same manner as in Example 1, and a block copolymer composition of Comparative Example 1 was collected. The block copolymer composition was fabricated into pellets and was thereby formed into a film of Comparative Example 1. Measurements were made for this film. The results are presented in Table 2.

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