Preparation And Properties Of Flame Retardant Polyolefin Compound

Most insulator and sheathe are made from organic polymers, which are easy to burn at certain temperature and oxygen content. It is necessary to improve the fire resistance of polymers used in wire and cable, for the safety reason. At present, most of flame retardants used for polyolefin cable are halogenated compounds and metal hydroxides.As a high effective halogenated flame retardants, decabromodiphenyl ether (DBDPO) plays an important role in flame-retarded cable. It is uncertain whether addition of DBDPO affects the aging properties of resin. Effect of DBDPO/Sb₂O₃ on the thermal aging properties of flame-retarded polyethylene (PE) was studied by natural aired electric aging box and Differential Scanning Calorimetry (DSC). Mechanical test showed that, after thermal aging, the tension strength of halogenated flame retarded. LDPE increased a little, but the elongation at break dropped badly. Oxygen induction index (O.I.T) decreased after ageing for LDPE with or without flame retardant. The O.I.T of LDPE treated by bromine/antimony flame retardant system, significantly increased, compared to the O.I.T of LDPE without flame retardant. Further study showed that only Sb₂O₃ was responsible for the increase of O.I.T, rather than DBDPO.Metal hydroxides, Al(OH)₃ and Mg(OH)₂, are the main halogen free flame retardants used in wire and cable. However, metal hydroxides are not compatible with polymers. It is necessary to surface treatment. In this paper, various coupling agents were chosen to treat magnesium hydroxide (MH). The influence of surface treatment on mechanical properties, processing and dispersion of MH in LDPE were studied. Mg(OH)₂ treated by coupling agents could obviously improve the break elongation of composites, but lead a slight decrease of tension strength. SilaneA151, fatty acid zinc stearate (Ste-Zn), titanateJN201, showed better surface treating performance.Bromine/antimony flame retardant system, red phosphorus masterbatch, or...