The present invention provides a process for preparing a stable graft polyol dispersion. The graft polyol dispersion has low viscosity and a high solids content. An ethylenically unsaturated monomer is polymerized in a polyol mixture including a macromer polyol and a carrier polyol. A free radical initiator and a reaction moderator are also present during polymerization. The reaction moderator is of the formula:
wherein
R is a phenyl group,
R1 is selected from the group of an aliphatic hydrocarbon radical having 1 to 18 carbon atoms, and
R2 is selected from the group of a phenyl group, a nitrile group, a methoxycarbonyl group, a carbamoyl group, and combinations thereof.
本发明提供了一种制备稳定接枝多元醇分散体的工艺。接枝多元醇分散体具有低粘度和高固体含量。
乙烯不饱和单体在多元醇混合物(包括大分子多元醇和载体多元醇)中聚合。在聚合过程中还存在自由基
引发剂和反应调节剂。反应调节剂的结构式如下
其中
R 是苯基、
R1 选自具有 1 至 18 个碳原子的脂肪族烃基,以及
R2 选自苯基、腈基、甲氧基羰基、
氨基甲酰基及其组合。