| 摘要 |
<p>Production of heat-cured resinous articles uses casting techniques as with thermoplastic materials. A heated mould is immersed in a liquid mixture contng. polyfunctional prepolymers of which at least one is a polyfunctional polydiene having vinyl side groups at alternating C-atoms of an extended carbon main chain. The mixture also contains a polyfunctional org. chain extender capable to react with the functional gps. of the polydiene, and a free-radical peroxide initiator adapted to promote cyclisation and crosslinking of the vinyl side gps. The heated mould is kept in motion within the liquid mixture. The elastomeric casting so obtained is then released from the mould and finally heat-cured. The polyfunctional polydiene may be dihydroxy-1,2-polybutadiene and/or dihydroxy-3,4-polyisoprene. Th chain extender may be a substd. aliphatic or aromatic diisocyanate, dibasic acid halide, dibasic acid and/or diester compound. The process favours formation of elastomeric products, at relatively low temps. having uniform thickness. Curing is rapid. The mould may be kept at constant temp. which reduces fuel costs and duration of moulding cycles.</p> |
