| 摘要 |
The invention relates to the preparation of polymers of at least one vinyl aromatic monomer grafted onto at least one unsaturated polyolefin elastomer, by polymerization of the said vinyl aromatic monomer in the presence of the said unsaturated polyolefin elastomer, in aqueous suspension and in two stages. The first polymerization stage is carried out at a temperature less than or equal to 130 DEG C in the presence of at least one chain transfer agent and at least one radical initiator R exhibiting high heat stability. In the second stage the polymerization is carried on at a temperature above that of the first stage, after addition of water and of a mixture of at least two radical initiators different from R and selected from tertiary butyl perbenzoate, di-tertiary butyl peroxide and 2,5-dimethyl-2,5-ditertiary butyl-peroxy-3- hexyne. |
