HIGH MOLECULAR WEIGHT DISPERSIONS FOR POLYMER POLYOLS

摘要

Low viscosity polymer polyol polyols having high styrene/acrylonitrile ratios and good stability may be achieved by the use of a high molecular weight (HMW) dispersant polyol comprising less than 5 wt.% of the total polyol component of the polymer polyol. The HMW dispersant should have a molecular weight higher than about 6000. Preferably, a semi-batch reactor is used, and a relatively high concentration of the HMW dispersant is initially charged to the reactor, relative to the portion of base polyol, which has a molecular weight of less than 4000.