| 摘要 |
<p>Polymerisation of a vinylaromatic monomer is effected in an aqs. suspension system comprising as first suspending agent a vinyl alcohol homopolymer or a copolymer comprising >=95 mol. % of polymerised vinyl alcohol, and as second suspending agent a comprising 75-91 mol. % of polymerised vinyl alcohol. The mixture of suspending agents leads to very good stability and control of the average size of beads produced. The aq. suspension pref. contains 0.03-0.5 wt. %. of first suspending agent and 0.002-0.05 wt. % of the second suspending agent. A surface active agent may be present. The vinyl aromatic monomer may be styrene or a halostyrene or alkylstyrene.</p> |
