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Polyolefin widely used in electronics, electrical appliances, machinery and other industries. However, the polyolefin flammability makes it a potential source of fire. Because people for the use of halogenated flame retardants bring the environmental issues of concern to carry out non-halogen flame retardant polyolefin research is of great significance. In this paper, two methods of halogen-free flame retardant polyolefin. First, take into account the rich brucite resources, to water magnesium powder as the main flame retardants. First, the study of water magnesium powder flame retardants, and Microencapsulated Red Phosphorus, zinc borate flame retardant synergist the system LDPE / EVA combustion properties, mechanical properties, thermal properties. Second, the amount of water magnesium powder, the amount of red phosphorus microcapsule and LDPE / EVA ratio as orthogonal factors obtained by orthogonal experiment a good flame retardant properties and mechanical properties of halogen-free flame retardant cable compound formulations. Meanwhile, the use of a variety of surface modifier ADDP, stearyl sodium aqueous magnesium powder was subjected to surface modification, the amount of water absorption, oil absorption, the contact angle for characterization means examines the kind and amount of the modifier on the surface modification sexual effects. By analyzing the changes of the contact angle of infrared spectroscopy and solvent washing modified water magnesium powder, to explore the mechanism of adsorption. SEM observation after modification for water magnesium powder dispersed in plastics. The experiments showed that the water in the modified magnesium powder has been the transition from hydrophilic to hydrophobic; adsorption mode both chemical adsorption have physical adsorption; modified water magnesium powder more uniformly dispersed in the LDPE / EVA, and LDPE / EVA compatibility also improves. Finally, the application of the water magnesium powder modified polyolefin flame retardant formulations and results show that, using the modified water magnesium powder to improve the flame retardancy and mechanical properties, flame-retardant materials reach a halogen-free flame retardant cable material standards. In addition, the experiment also showed that the surface modifier adsorbed way will affect the performance of flame retardant composites. Second, the use of phosphoric acid, phosphorus pentoxide, the pentaerythritol, cyanuric ammonium synthesized from of pentaerythritol phosphate cyanuric ammonium salts flame retardant, according to the degree of expansion of the flame retardant, the char and water absorption rate determined The optimal synthesis conditions. Then, the flame retardants used in low-density polyethylene, low density polyethylene expansion of the oxygen index level combustion method, and the tensile properties of test visits retardant properties and mechanical properties of the flame retardant system. Experimental results show that the degree of expansion, the char rate can reflect the intumescent flame retardant effect of low density polyethylene. 3:1:1 expandable fire-retardant formulations with low density polyethylene to 30:70 (mass ratio) were mixed, the composite material can reach levels of flame-retardant level FH-1, the oxygen index reaches 29, the self-extinguishing time is 30s, having good The flame-retardant effect. In addition, the use of thermal gravimetric analysis and differential thermal analysis means initially explore the mechanism of flame retardant halogen-free flame retardant system.
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