Binary acrylonitrile copolymer spinning fluid and preparation method thereof

Abstract

The invention relates to a binary acrylonitrile copolymer spinning solution for carbon fibers with uniform chain structure. The composition of this spinning solution is the dimethyl sulfoxide solution of the copolymer of main monomer acrylonitrile and itaconic acid β-monoester; the main monomer is 90~99.5% of the monomer weight, and the comonomer weight is 0.5-10% of the weight of the monomer, the monomer is the main monomer and comonomer, and the weight percentage concentration of the monomer is 15-25%. Add the solvent dimethyl sulfoxide, main monomer acrylonitrile, comonomer, and free radical initiator azobisisobutyronitrile according to the proportioning ratio into the reactor, stir and mix at room temperature, and after bubbling nitrogen for 20 minutes, Under nitrogen protection, react at a constant temperature of 50-70°C for 6-36 hours, remove residual monomers and bubbles, and obtain the product. Its chain structure is uniform, and itaconate β-monoester contains both carboxyl and ester functional groups, which can not only improve the spinnability of polyacrylonitrile resin but also regulate the oxidation-carbonization process of carbon fiber precursors; due to the bifunctional monomer The introduction of itaconate β-monoester greatly reduces the amount of comonomer with acrylonitrile, leading to the improvement of carbon fiber performance.

Description

technical field [0001] The invention relates to a spinning solution of a binary acrylonitrile copolymer for carbon fibers with a uniform chain structure and a preparation method. Background technique [0002] Carbon fiber has the characteristics of high specific strength, high specific modulus, heat resistance, corrosion resistance, fatigue resistance, creep resistance, etc. It is a high-performance fiber material and has been widely used in aerospace, national defense construction, sports and leisure products, medical equipment and construction industries. Polyacrylonitrile-based carbon fibers have outstanding mechanical properties and are a hot spot in carbon fiber research in recent years. Some people think that high-quality polyacrylonitrile precursor is one of the keys to the preparation of high-performance polyacrylonitrile-based carbon fiber, and to obtain high-quality polyacrylonitrile precursor must be synthesized from high-quality acrylonitrile copolymer spinning ...

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Problems solved by technology

However, ternary radical copolymerization is a very complicated process, especially in the case of a large difference in the reactivity ratio between monomers and a high conversion rate, and the controllability is even worse.

Using a bifunctional monomer with a reactivity rate close to that of acrylonitrile and having both the functions of unsaturated carboxylic acid and unsaturated carboxylic ester as a comonomer to carry out binary copolymerization with acrylonitrile to prepare carbon fiber spinning solution has not yet been see literature report

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