Flame-retardant acrylonitrile copolymer and preparation method thereof

Abstract

The invention discloses a flame-retardant acrylonitrile copolymer and a preparation method thereof. The flam-retardant acrylonitrile copolymer comprises the following structural formula: in the structural formula, X is R2OP(O)-substitutional group or R2OP(S)-substitutional group and R is methyl or ethyl. The preparation method adopts the following steps of: (1) co-polymerization: preparing an acrylonitrile-vinyl acetate copolymer; (2) hydrolyzation: preparing a neutral acrylonitrile-vinyl alcohol colymer generated by hydrolyzing a vinyl acetate unit; and (3) flame-retardant modification: adding a flame-retardant modifying agent for modifying reaction to obtain the copolymer, wherein the flame-retardant modifying agent is dimethoxy phosphoryl chloride, diethoxy phosphoryl chloride, dimethoxy thiophosphoryl chloride or diethoxy thiophosphoryl chloride.

Description

technical field The invention relates to a preparation technology of a flame-retardant acrylonitrile copolymer, in particular to a flame-retardant acrylonitrile copolymer without halogen elements and a preparation method thereof. Background technique Polyacrylonitrile and its copolymers are good fiber-forming and film-forming polymers with good chemical stability, oxidation resistance and solvent resistance. At present, there are many monomers copolymerized with acrylonitrile, such as vinyl acetate, methyl acrylate, methyl methacrylate, acrylamide, styrene, butadiene, sodium methacrylate, etc. However, these copolymers and polypropylene Nitrile has a low limiting oxygen index value and is a flammable substance. With the formulation and improvement of flame retardant regulations, the application of polyacrylonitrile and acrylonitrile copolymers in fiber and film materials is limited to a certain extent. As the main application field of polyacrylonitrile and acrylonitrile c...

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Problems solved by technology

Ren Yuanlin, etc. have done a lot of work on halogen-free flame-retardant acrylonitrile copolymers (referring to 1. Lu Zhengming, etc., a kind of flame retardant and its preparation method and the flame-retardant acrylic fiber using this flame retardant, Chinese patent, CN 101113211, 2007; 2. Ren Yuanlin et al., Non-isothermal thermal decomposition kinetics of a novel flame-retardant polyacrylonitrile copolymer in air. Acta Chem. Sinica, 2009, 67(18): 2127-2132; 3. Ren Yuanlin et al., Methacrylic acid Synthesis and application of 2-(diethoxyphosphorothioate) ethyl ester. Fine Chemical Industry, 2008, 25(8): 829-832; 4. Jiang Aibing et al., Diethoxyacrylamide methoxy Synthesis and application of phosphorothioate (DMAT). Applied Chemistry, 2009, 26(2): 206-209; .Fine Chemical Industry, 2009, 26 (2): 105-108), and achieved a good flame retardant effect, however, due to the relatively low yield of flame retardant comonomer synthesis, and the separation and purification process is more complicated, and The conversion rate of flame retardant comonomer is low when copolymerized with acrylonitrile. In order to improve the flame retardant effect of flame retardant acrylonitrile copolymer, the copolymerization content of flame retardant comonomer has to be increased, which undoubtedly increases the flame retardant acrylonitrile. Copolymer Development Costs