| 摘要 |
A char-forming compsn. comprises (A) a polymer comprising (1) an ethylenically unsatd. carboxylic anhydride in an amt. providing >=1 equiv. anhydride moiety per g. compsn. and (2) a monovinylidene aromatic monomer in an amt. providing >=1 equiv. reactive aromatic moiety per g. compsn. and (B) an ester of formula (CF3SO3CH2)nR, where n is a positive integer and R is an n-valent tert.-hydrocarbyl gp. (opt. inertly substd.). Typical compsn. comprises CF3SO3CH2C(CH2Br)3 and styrene-maleic anhydride (75:25) copolymer. The compsn. is used in the mfr. of moulded articles such as containers, housings for machines and electrical equipment and cabinets for electrical appliances. It can also be employed in foamed form for thermal insulation, light construction or furniture mfr. On combustion of the compsn. a char is formed. The char barrier impedes migration of combustible material to the combustion point, enhances the structural integrity of the burning article, inhibits dripping of molten polymer, thermally insulates the unburned portion from generated heat and reduces smoke emission. |
