| 摘要 |
PURPOSE: Provided are mixtures of polystyrene and of polyphenylene ether, to which triblock copolymers S-B-M have been added in order to improve their impact strength. CONSTITUTION: The rigid material based on PPO of the formula(I) and an aromatic vinyl resin with improved impact strength comprises: 99 to 20% of a resin(A) consisting of a mixture of PPO and of an aromatic vinyl resin; 1 to 80% of an impact modifier comprising at least one block copolymer S-B-M wherein, each block is linked to the other by a covalent bond or an intermediate molecule linked to one of the blocks by a covalent bond and to the other block by another covalent bond, M consists of MMA monomers optionally copolymerized with other monomers and comprises at least 50% by weight of methyl methacrylate (MMA), B is incompatible with the resin(A) and with the M block and its glass transition temperature Tg is less than the temperature for using the rigid material, S is incompatible with the B block and the M block and its Tg or its melting point m.p. is greater than the Tg of B, S is compatible with the resin(A).
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