| abstract |
The present invention relates to an impact modifier, a device and a method for manufacturing said impact modifier, and a process for preparing a thermoset material, or a precursor of thermoset material, from said impact modifier. Said impact modifier comprises at least one copolymer chosen from ABA, AB and ABC type block copolymers, in which: each block is connected to the other by means of a covalent bond or an intermediate molecule connected to the 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 is preferably 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; the blocks A and C may be identical, B is incompatible or partially compatible with the thermoset resin and incompatible with the block A and the optional block C. Typically, impact modifier is in the form of microgranules with a diameter of less than 1500 um, advantageously less than 1000 μm, preferably between 400 and 1000 μm. |