| 摘要 |
Described are epoxidized linear or branched block copolymers, which can be defined by the following formulae: [A-(E-B-EPOX)]nX (I> [(E1-B1-EPOX1)-HT-A-(E2-B2-EPOX2)]nX (II> A1-(E1-B1-EPOX1)A-HT-(E2-B2-EPOX2) (III> wherin A, A1 and A2 are polyvinylaromatic blocks, E-B-EPOX is a block composed of ethylene, butylene and epoxidized butadiene units, HT is a tapered copolymeric segment composed of hydrogenated and epoxidized diene and vinylaromatic units whose content ranges from 0 to 20%, and X is a radical having a valence n ranging from 1 to 20. The block copolymers have an average molecular weight ranging from 30,000 to 400,000, a content of polyvinylaromatic blocks of between 10 and 50% by weight and a content of (E1-B1-EPOX1)+(E2-B2-EPOX2) blocks ranging from 90 to 50% by weight; the weight ratio of (E1-B1-EPOX1) and (E2-B2-EPOX2) ranges from 0.1:1 to 1.0:1. These polymers are useful in the preparation of polymeric compositions based on engineering polymers such as polyamides, polycarbonates and polyesters, improving physical properties and above all impact strength of the latter, and in admixtures with oils and hydrocarbon resins, for the production of materials showing excellent adhesion to polar substrates. |
