摘要 |
Novel polymer polyols based on halogenated aromatic monomers such as tribromostyrene give polyurethane foams with improved flame retardant properties. For example, replacing conventional SAN polymer polyols with tribromostyrene (TBS)/acrylonitrile polymer polyols allows the preparation of polyurethane foams passing British Standard 5852, Part 2, Ignition Source 5 Combustion Test and having better ASTM E-906 values without the need for solid fillers such as melamine or aluminum trihydrate, although these and other flame retardant additives may be optionally employed as well. Elimination of these fillers also provides other improvements such as superior strength and better compression set properties. The TBS dispersions may also be used in conjunction with melamine to eliminate the need for liquid fire retardant additives. |