Nanometer SiO2 doped composite EVA/PA6 alloy flame-resistant material and preparation method thereof

Abstract

The invention discloses a nanometer SiO2 doped composite EVA / PA6 alloy flame-resistant material and a preparation method thereof. The SiO2 doped composite EVA / PA6 alloy flame-resistant material mainlycomprises ethylene-vinyl acetate, nylon, an intumescent flame retardant and nano-silica; the nano-silica is modified; the modified nano-silica is uniformly premixed with EVA, PA6 and the intumescentflame retardant, and then the materials are melted, blended and pelletized to obtain the product. According to the nanometer SiO2 doped composite EVA / PA6 alloy flame-resistant material, the modified nano-silica is added to a polymer, and the modified nano-silica and the intumescent flame retardant achieve the synergistic flame retardant effect; smoke droplets are avoided during combustion, so thatthe released smoke is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of flame retardant materials, in particular to a doped nano-SiO 2 Composite EVA / PA6 alloy flame retardant material and preparation method thereof. Background technique [0002] Ethylene-vinyl acetate (EVA) is a copolymer of ethylene and vinyl acetate in different proportions. EVA has good elasticity, flexibility, adhesion, low temperature toughness, stress crack resistance, weather resistance and chemical resistance. Although EVA has good toughness, it also reduces the tensile strength, hardness, and rigidity of EVA materials, resulting in low mechanical strength and non-wear resistance, which limits its further application. Blending can make the performance advantages of different polymers complement each other, so that the performance of the original polymer can be improved, thereby improving the performance of a certain aspect of the material. Nylon 6 (PA6) is a thermoplastic engineering plastic with exc...

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Problems solved by technology

[0004] Common additive flame retardants can be divided into halogen-based flame retardants and halogen-free flame retardants. Halogen-based flame retardants have good flame-retardant effects, but they emit a large amount of toxic and harmful gases (such as HC1, HBr, etc.), hydrogen halide gas easily absorbs moisture in the air to form hydrohalic acid, which has a strong corrosive effect, causes secondary pollution, and produces a large amount of smoke; it is also severely corrosive to processing equipment. Therefore, the halogen series It has become a consensus in the flame retardant industry that flame retardants are replaced or replaced by halogen-free flame retardants;

[0005] Among the halogen-free flame retardants, ammonium polyphosphate (APP) is a widely used inorganic phosphate flame retardant, which has high phosphorus content, high nitrogen content, good flame retardant effect, good thermal stability, smoke suppression, However, when it is used alone as a flame retardant, there is a large amount of addition. While improving the flame retardancy of polymer materials, it often affects its other properties, and the nitrogen system Flame retardants do not have the effect of promoting char formation, and the flame retardant effect is not ideal when used alone as a flame retardant. Therefore, they are often used in combination with ammonium polyphosphate, pentaerythritol and other flame retardants or char-forming agents to achieve the best flame retardant effect. further improvement;

[0006] Nano silicon dioxide (SiO 2 ) is a nano-scale inorganic filler, adding nano-silica to the polymer can prepare a silica-based nanocomposite material, which has good thermodynamic stability, and at the same time, nano-silica can be combined with expansion resistance The flame retardant has the effect of synergistic flame retardancy. Both the intumescent flame retardant and the nano flame retardant have the advantages of non-toxicity and environmental protection. Therefore, the synergistic use of the two is not only environmentally friendly and non-toxic, but also can use The synergistic effect of the former reduces the amount of intumescent flame retardant. However, nano-silica is a powder, and when the nano-silica of the powder is mixed with other pellets and fed into the twin-screw blending granulation, due to the Inconsistency with the feeding speed of the powder will result in more pellets in one section and more powder in a certain section, which will lead to deviation and affect the quality of the finished product

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