Preparation And Properties Of Halogen-Free Flame Retardant Silane-Crosslinked POE Composite

The rapid development of economy in our country brings out the rapid increase of demand of cable and wire in recent years, especially in the projects of rural electrical transportation and urban construction. The increase is not only reflected in the quantity, but also in the quality. In the RoHS directive, some hazard substances, including some halogen-containing flame retardants and heavy metals, are strictly limited in the use of electrical equipment and appliance. So the toxic-containing cable materials will retreat in the market gradually. In spite of PVC cables using by now, halogen-free cables have been becoming a big market and the environment-friendly cable materials with high quality will be a new topic in research.POE is a kind of non-polar material with saturated molecular chains, and therefore exhibits good electrical properties, resistance to oxygen and ozone, as well as high-temperature aging resistance. All these properties lead POE to be suitable for application in the cable as sheath jacket materials to replace PVC, Chloroprene Rubber, Chlorosulfonated Polyethylene. And there is a good prospect in application.In this paper, we have used silane-crosslinked POE as matrix, magnesium hydroxide as a major halogen-free flame retardant, EVA as compatibillizer, and MRP, MCA, ZR3, ASBP as synergistic flame retardant, to develop a kind of halogen-free silane-crosslinked cable material, which exhibits excellent mechanical properties and flame-retardant performance, good electrical properties and processing performance, and high-temperature aging resistance. Firstly, we studied the effect of MH content on flame-retardancy, tensile properties, electrical properties, hot set test, as well as high-temperature aging resistance of the composites. The results showed that the composite with 140phr MH as flame retardant exhibited excellent mechanical properties and flame-retardant performance, good electrical properties and processing performance, and high-temperature aging resistance, and could pass the hot set test. Secondly, we studied the effect of EVA content as compatibillizer between XPOE and MH. The results showed that high-temperature aging resistance and elongation at break were greatly improved when 10phr EVA was added as compatibillizer in the composite, which exhibited excellent flame-retardant performance and could pass the hot set test. Finally, we used MRP, MCA, ZR3 and ASBP as synergistic flame retardant with MH and studied synergistic effect of the content of MRP, MCA ratio in blends of MRP and MCA, and the four different flame retardants individually with 2phr in amount on the properties of the composites. The results showed that the composite with MCA was seriously deteriorated in the elongation at break and couldn't pass the hot set test, while the tensile strength of the composite with ZR3 was badly lost. And the composites with MRP or ASBP exhibited excellent mechanical properties and flame-retardant performance, good electrical properties and processing performance, and high-temperature aging resistance, and could pass the hot set test, which can meet the demand of sheath jacket materials in production and are promised a broad market value.