| 摘要 |
<p>A flame-resistant moulding composition comprises a major proportion by weight of monomeric or polymeric styrene and at least one organic bromine compound containing aliphatically and cycloaliphatically bonded bromine in the molecule. The composition may contain 0.5-3.0% of bromine derived from the bromine compound which may be dibromoethyl - dibromocyclohexane (i.e. tetrabromovinyl - cyclohexane) together with a synergist, e.g. dicumyl peroxide. The composition may be formed into articles by shaping (and hardening, in the case of monomeric styrene) at elevated temperatures. The bromine compound may be added to the granulated polymer by spraying as a solution or suspension in an organic solvent, e.g. petroleum ether or styrene. The composition may be foamed, e.g. by incorporation of pentane or decomposable nitrogenous compounds and then heating. In comparative examples polystyrene is compounded with monochloro-tetrabromo-diphenyl, tetrabromo-ethane or 1-chloro-2,3-dibromo-propane, with optionally dicumyl peroxide.</p> |
