A kind of halogen-free flame-retardant polyethylene material and preparation method thereof

Abstract

The invention relates to a preparation method of a halogen-free flame-retardant polyethylene material, including the steps of preparation of a hybrid silica sphere, preparation of a three-source-integrated intumescent flame-retardant molecule, graft copolymerization, treatment of expandable graphite and conductive carbon black with a coupling agent, and raw material extrusion or pressing forming.The invention also relates to the halogen-free flame-retardant polyethylene material, including polyethylene, a silicon dioxide / polyethyl methacrylate pentaerythritol phosphate melamine salt hybrid flame retardant, the expandable graphite, the conductive carbon black and the coupling agent. The beneficial effects of the invention are as follows: a silicon compound has a good synergistic flame retardant effect, the surface of the prepared hybrid silica sphere containing vinyl groups is rich in vinyl double bonds, the hybrid silica sphere and ethylene monomers are subjected to graft copolymerization to form a crotch-shaped structure, an organic-inorganic network is added into a polymer matrix, the dispersion effect of silicon in the matrix is improved, the formation of the continuous dense cross-linked carbon layer is facilitated, and the flame retardant efficiency is increased; and the addition of the expandable graphite has a great synergistic flame retardant effect.

Description

technical field [0001] The invention relates to a halogen-free flame-retardant polyethylene material and a preparation method thereof. Background technique [0002] The traditional method of flame retardant modification of PE is to add halogen-containing flame retardants. This type of flame retardant has long occupied a dominant position in the field of PE flame retardants due to its high flame retardant efficiency, low dosage, and low price. However, with the progress of society and the enhancement of people's awareness of environmental protection, the contradiction between the disadvantages of halogenated flame retardants and the needs of social development has become increasingly acute. Since the 1990s, the halogen-free flame retardant technology has developed rapidly. At present, the halogen-free flame retardant modification of PE is still mainly based on adding flame retardants. Commonly used halogen-free flame retardants are: metal hydroxide flame retardants, phosphor...

AI Technical Summary

Problems solved by technology

But it also has obvious disadvantages: (1) The existing intumescent flame retardants are mostly composed of polar small molecular substances, which have poor compatibility with non-polar PE matrix, making it difficult for the mechanical properties and processing properties of materials to meet the use requirements (2) Most of the existing intumescent flame retardants have problems such as easy moisture absorption and easy migration; (3) The thermal stability of the existing intumescent flame retardants is insufficient, and esterification reactions are prone to occur during processing, and water vapor is released , adversely affect the appearance and mechanical properties of the product

(4) The flame retardant efficiency is not high, and the addition amount is too large

This kind of flame retardant has a higher flame retardant efficiency than traditional IFR because the acid source, gas source and carbon source can act at a closer distance, but the char formation is often not ideal

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