| 摘要 |
T 4840 BLOCK COPOLYMER OF POLYALKYLENE AND HALOGENATED POLY(VINYL AROMATIC) A block copolymer is provided having the general formula S'-A-(A-S')m in which m is 1, 2, 3 or 4, A is a polyalkylene block and S' is a nuclear brominated and/or chlorinated poly(vinylaromatic) block having from 0.5 to 5 bromines and/or chlorines per aromatic ring. The polyalkylene block is substantially free of halogen. The block copolymer is prepared by polymerizing the monomers, hydrogenating the formed polymer in the presence of a hydrogenation catalyst and subsequently halogenating the hydrogenation catalyst and the hydrogenated polymer, all steps successively being carried out in the same, inert solvent. The compositions retain the elastomeric properties of the non-halogenated form of the compounds while having significantly reduced flammability along with improved tensile strength and high temperature properties. C11/T4840FF
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