Abstract: The present invention relates to an impact modifier and a device and a method for the production thereof, as well as to a method for preparing a thermoset material, or a thermoset material precursor, from the impact modifier. The impact modifier comprises at least one copolymer selected from A-B-A, A-B, and A-B-C block copolymers in which: each block is linked to the other by means of a covalent bond or an intermediate molecule that is connected to one of the blocks by a covalent bond and to the other block by another covalent bond; A is a PMMA homopolymer or a copolymer of methyl methacrylate, A preferably being compatible with the resin; C is either (i) a PMMA homopolymer or a copolymer of methyl methacrylate, or (ii) a polymer based on monomers or a mixture of vinyl monomers, and blocks A and C are identical; and B is incompatible or partially compatible with the thermoset resin and incompatible with block A and optional block C.

Abstract: The invention relates to a mixture which is useful as a coextrusion binder, comprising: at least (A) one polyethylene or one ethylene copolymer, at least (B) chosen from (B1) polypropylene or a propylene copolymer, (B2) poly(1-butene) homo- or copolymer, and (B3) polystyrene homo- or copolymer, the mixture of (A) and (B) being grafted with a functional monomer, this grafted mixture itself optionally being diluted in at least one polyolefin (C) or in at least one polymer (D) of elastomeric nature or in a mixture of (C) and (D). The invention also relates to polyolefin/binder/polyamide, EVOH, polyester or metal structures. The invention is useful for making packaging.