Polymeric compositions possessing improved flammability resistance

The composition of matter prepared by the process comprising melt blending of a copolymer of a monoalkenyl aromatic monomer and an ethylenically-unsaturated anhydride with a brominated primary aliphatic amine or brominated aromatic substituted aliphatic primary amine at a temperature below the temperature at which the copolymer significantly degrades and for a length of time sufficient to convert an effective amount of the ethylenically-unsaturated anhydride present in the copolymer to an imide.

The composition of matter prepared by the process comprising reacting an ethylenically-unsaturated anhydride with an amount of a brominated primary aliphatic amine or brominated aromatic substituted aliphatic primary amine for a length of time sufficient to react at least part of the ethylenically-unsaturated anhydride with the brominated primary aliphatic amine or brominated aromatic substituted aliphatic primary amine to form an imide, and polymerizing the resultant imide with a monoalkenyl aromatic monomer.

A foamed polymeric composition comprising styrene having maleimide polymerized therein in an amount of from about 5 to about 25 mole percent, said maleimide having appended, to the nitrogen atom, a 2,4,5-tribromobenzyl radical.