| 摘要 |
<p>The compsn. is prepd. by polymsg., in the presence of a free radical initiator, while maintaining a low monomer: polyol ratio in the reaction mixt., (I) 10-30 wt. % of a mixt. of (a) 33-75, esp. (45), wt. % methacrylonitrile or esp. acrylonitrile, and (b) 25-67, esp. (55),wt. % a-methylstyrene or esp. styrene, in soln. or dispersion in (II) 70-90wt. % liq. polyol having an OH no. of 20-150, esp. 40-70, to give polymer particles having a dia. 1mu. Gives polyurethane foams with good physical props. as scorching is avoided.</p> |
