This invention relates to flame retardant polymers and particularly to fire retardant terpolymers of styrene and maleic anhydride.
Polymers of styrene and maleic anhydride are well known for their high heat distortion temperature but they have the limitation that they burn when ignited. For many end uses a polymeric molding composition is required to be flame-retardant to meet the applicable safety codes.
The present invention provides a route towards flame retardant compositions based on styrene/maleic anhydride polymers that also retain good strength and molding characteristics.
While it is known that polyvinyl chloride is resistant to burning, its use as a flame retardant additive may be impeded if this requires significant sacrifice of other desirable properties such as impact strength.