| 摘要 |
<p>Styrene, opt. mixed with other monomers, and contg. 0.001-0.1wt.% brominated oligomers or polymers of a 1,3-diene, is polymsd. in presence of low-boiling hydrocarbons as blowing agents and during mfr. is heated to 110-140 degrees (115-135 degrees)C. The pearl polymers obtd. can be pre-expanded in steam and the beads finally expanded with steam under pressure in closed moulds as usual. Min. time of demoulding e.g., of large blocks can be substantially deduced without harmful shrinkage or collapse after removal from the mould.</p> |
