| 摘要 |
A process for the preparation of expandable polymer particles containing a polymer of a vinylarene monomer and a foaming agent, which process comprises: 1) polymerizing, by suspension polymerization, 100 parts by weight of a vinylarene monomer, in the presence of 1 to 20 parts by weight of a radical initiator having a half life of 1 hour in benzene at 70 to 110 DEG C., until at least 60% of the vinylarene monomer is polymerized; 400 to 4,900 parts by weight additional vinylarene monomer as well as 0.05 to 1% wt, based on the amount of vinylarene monomer added in step 2, of a radical initiator having a half life of 1 hour in benzene at 70 to 110 DEG C. and polymerizing to completion, in which process the blowing agent can be added before, during or after the polymerization process. |
