| 摘要 |
<p>1436763 Two-block copolymers SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV 2 May 1973 [4 May 1972] 20817/73 Heading C3P [Also in Division C5] A copolymer having the formula A-B wherein A is a hydrogenated polymer block of a conjugated diene and B is a polymer block of a monoalkanyl pyridine, a(meth)acrylate, a methacrylonitrile, or an alphaolefin oxide or a hydrogenation product of such a block, is obtainable by the usual two-stage sequential polymerization using one alkyl lithium initiator, followed by hydrogenation. Desirably the diene block if derived from butadiene, has a substantial 1,2-content prior to hydrogenation. In examples, butadiene-2-vinyl-pyridine, -methacylonitrile, -ethylene oxide and isoprene-2- vinyl pyridene block copolymers are prepared using alkyl lithium initiators in hydrocarbon or hydrocarbon ether solvents, with addition of KO-t-Bu in the ethylene oxide step. The polymers are hydrogenated using nickel dioctoate or nickel acetylacetonate together with aluminium triethyl or trisobutyl, the polymers containing vinyl pyridine units being first treated with boron-trifluoride to prevent catalyst inactivation. The copolymers are useful as lube oil additives.</p> |
