Use of a polymer as a secondary suspending agent in a suspension polymerization reaction is provided. The polymer comprising (i) residues of at least one ester-containing monomer, the ester-containing monomer (s) comprising one polymerizable carbon-carbon double bond per monomer and an ester group, and (ii) residues of at least one monomer comprising a sulfonate, sulfonic acid, sulfonic ester, sulfonamide or sulfonyl halide group the monomer (s) comprising a sulfonate, sulfonic acid, sulfonic ester group, sulfonamide or sulfonyl halide group comprising one polymerizable carbon-carbon double bond per monomer and a sulfonate, sulfonic acid, sulfonic ester, sulfonamide or sulfonyl halide group, the polymer optionally being partially hydrolyzed such that a proportion of said ester groups form alcohol groups, the degree of hydrolysis of the polymer being from 0 to 30 mol %.
本发明提供了一种在悬浮聚合反应中用作二级悬浮剂的聚合物。该聚合物包括(i) 至少一种含酯单体的残留物,含酯单体包括每个单体一个可聚合的碳碳双键和一个酯基,以及(ii) 至少一种单体的残留物,该单体包括
磺酸盐基、
磺酸基、
磺酸酯基、磺酰胺基或磺
酰卤化基,
磺酸盐基、
磺酸基、
磺酸酯基、磺酰胺基或磺
酰卤化基包括每个单体一个可聚合的碳碳双键和一个酯基、
磺酸基、
磺酸酯基、磺酰胺基或磺
酰卤化基,聚合物可选择部分
水解,使一定比例的所述酯基形成醇基,聚合物的
水解度为 0 至 30 摩尔%。