Development Of High-Powered Halogen-Free Flame Retardant Polyolefin Composites

Polyolefin Cable can easily conflagate in heat and high pressure. Halogen flame retardant which have excellent flame retardant properties have been used widely. But they give birth to many smog and noxious gas. Accordingly, to develop non-halogenated flame-retardant system becomes an attractive and emergent subject.Among non-halogenated flame retardants, hydroxid and phosphorus-based flame retardants which was called no-social effects of pollution have been widely used in various polymeric materials. Because they can not produce noxious gas.This article study effect of Mg(OH)₂ and synergistic additives on EVA or POE composite mechanical properties and flame retardant properties. And develop good halogen-free flame retardant cable.Al(OH)₃ and Mg(OH)₂ powder, which had similar shape and particle size and distributing, were chosen as two kinds of halogen-free flame retardants for EVA. The effect of the amount of two flame retardants on the mechanical and flame retardant properties of the composites were discussed and compared with the composites incorporated with red phosphorus. The results showed that these effects were similar, which included the improvement of flame retardant properties and tensile strength, and the decrease of elongation at break as the increase of flame retardant. Shown by the results of cone calorimeter, the ignite time of Al(OH)₃ was short, the most and mean rate of heat release was low, and the flame performance index was high, the flame retardant properties was better than Mg(OH)₂. The effect of amount of red phosphorus was slight on the mechanical properties of composites, but its effect was larger on the flame retardant properties. Although the limit oxygen index of the composites of EVA increased with the increase of Mg(OH)₂ and red phosphorus, the general flame retardant properties of the composites of EVA with Al(OH)₃ and red phosphorus was better, considering the level and vertical flame.Magnesium Hydroxide as halogen-free flame retardant was used to study effect of its amount on composite mechanical flame retardant heat-resistant crystal and rheology properties. The results showed that LOI of composite increase with the increase of Mg(OH)₂. Vertical flame can achieve FV-0 when the amount of flame retardant is 65%. Anticipate purpose can not achieve when red phosphorus add to Mg(OH)₂/POE system. Filling of many uncoated Mg(OH)₂ can lead to the rapidly decreasing of composite mechanical properties which could be improved when Mg(OH)₂ is coated. Heat-resistant properties can increase with adding Mg(OH)₂.The dates of melt and crystal indicate that the flame retardant exerts an obvious heterogeneous nucleation in preparation of the POE. Composites G' and viscosity remarkable enhance with adding many Mg(OH)₂.We study effect of Mg(OH)₂/EG,Mg(OH)₂/RP on polymer materials flame retardant properties. And find Mg(OH)₂ and EG or RP optimal dosage. Study their mechanical properties and flame retardant properties.