| 摘要 |
1446183 Anionic copolymerization; pseudorandom copolymers UNIROYAL Inc 4 Sept 1973 [14 Sept 1972] 41433/73 Heading C3P [Also in Division C2] A monomer mixture comprising a conjugated diene and a vinyl aromatic hydrocarbon is copolymerized by contact with a catalyst comprising (a) an organomonolithium compound and (b) a potassium phenolate complex of the formula where each R<SP>1</SP> is an alkyl group at least one of which has 8 to 26 carbon atoms, y is 1 to 3, Ar is an arylene radical containing one aromatic ring, and R<SP>11</SP> is hydrogen or hydrocarbyl, in a solvent which is a saturated aliphatic hydrocarbon or aromatic hydrocarbon which does not contain benzylic hydrogen atoms (compounds such as toluene acting as molecular weight regulators in this system). The complex (b) is obtainable by reaction of a phenol with potassium hydroxide or hydrocarbyloxide. The copolymer products may be random or "pseudorandom". In particular a pseudorandom copolymer is characterized by (i) containing 23 to 50% by weight of the vinyl aromatic hydrocarbon, (ii) having blocks of 3 or 4 units of the vinyl aromatic hydrocarbon interspersed throughout the copolymer chain, (iii) a vinyl (1,2-) content of 7 to 15%, and (iv) a Tg which is at least 10‹ C. lower than the Tg of a random copolymer having the same vinyl aromatic hydrocarbon content. In the examples, butadiene and styrene are copolymerized in heptane or benzene in the presence of (a) C 4 H 9 Li and (b) C 9 H 19 -C 6 H 4 -OK.HOC 4 H 9 or a polyisobutylene phenol-KOH reaction product. |
