US Patent 7179882 Low viscosity polymer polyols

The present invention relates to low viscosity polymer polyols and to a process for the preparation of these low viscosity polymer polyols. These polymer polyols comprise the free-radical polymerization product of (A) a base polyol, (B) a pre-formed stabilizer, and (C) at least one ethylenically unsaturated monomer, in the presence of (D) at least one free-radical polymerization initiator, and (E) at least one polymer control agent. The total amount of polymer control agent present in the polymer polyols of the present invention ranges from greater than about 5.0% up to about 20% by weight, based on 100% by weight of the polymer polyol.