Isoprene → HCID 19842620, compound

Participants

Reaction Steps

A 10 L stainless steel polymerization reactor was washed, dried and refluxed with dry nitrogen. Then, 78 g of styrene, 4,800 g of cyclohexane and 6 Ml of n-butyl lithium (2M solution in cyclohexane) were charged into the reactor. Polymerization was initiated at 40° C. and the mixture was stirred for 30 minutes. Then, 644 g of isoprene was added and polymerization was allowed to proceed for 30 minutes. 78 g of styrene was again added and continuous polymerization was allowed to proceed for 30 minutes thereby to give a linear styrene-isoprene-styrene polymer. 1 g trimethylsilylchloride ((CH3)3SiCl) was added, the reaction mixture was stirred for 10 minutes and then reaction was terminated. A polymer thus obtained was dried at 60° C. under reduced pressure for 24 hours to obtain a linear styrene-isoprene-styrene block copolymer. The content of styrene and the content of vinyl of isoprene in an obtained rubber, measured by 1H-NHR, were 19.5% by weight and 8% by weight respectively. The analysis by GPC indicated that the polymer had a number average molecular weight (Mn) of 141,450.

Provenance & Evidence