| 摘要 |
Polymers of excellent impact strength, reduced particle size, and enhanced proportions of fines are obtained in the bulk polymerization of a vinyl halide or mixture thereof with comonomer(s) in the presence of a high molecular weight polyolefin added to the polymerization mass upon conversion of 0 to about 20% by weight of monomer(s) to polymer, by removing from the polymerization mass during the thick paste state thereof sufficient vinyl halide to adjust the effective concentration of polyolefin to above about 3.5% based on vinyl halide. The resultant product which contains an enhanced proportion of fines and is devoid of massive agglomerates, requires less mechanical work in comminution or shorter heating in melting in subsequent conventional processing steps.
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