Characteristics of polyacrylonitrile fibers! Do you understand?

The commercial name of polyacrylonitrile fibers is acrylic fibers, which are synthetic fibers made of acrylonitrile copolymers containing more than 85% of polyacrylonitrile or acrylonitrile. The properties of polyacrylonitrile fibers are very similar to wool, with good elasticity. When the elongation is 20%, the resilience can still be maintained at 65%. It is fluffy, curly and soft. Its warmth retention is 15% higher than wool, and its strength is 1-2.5 times higher than wool. It is known as synthetic wool. Polypropylene fiber

Because polyacrylonitrile fibers have the advantages of softness, bulkiness, non-dyeability, bright color, light resistance, anti-bacterial and moth resistance, they can be pure or blended with natural fibers according to the requirements of different uses, and their textiles are widely used in clothing, decoration and other fields.

Characteristics of polyacrylonitrile fibers!

Thermal properties of polyacrylonitrile fibers

Polyacrylonitrile fibers have special thermal shrinkage. When the fibers are stretched 1.1-1.6 times and cooled suddenly, the elongation of the fibers can not be restored temporarily. If the fibers are treated at high temperature under relaxation state, the fibers will shrink considerably accordingly. This property is called thermal elasticity of polyacrylonitrile fibers.

Hygroscopicity and dyeability of polyacrylonitrile fibers

The hygroscopicity is poor and the standard moisture regain rate is 1.2%~2%. Because the second and third monomers are added to the polyacrylonitrile fibers, the dyeing property is improved. Cationic dyes or acid dyes can be used to dye the polyacrylonitrile fibers.

Chemical Properties of Polyacrylonitrile Fibers

Polyacrylonitrile is stable to chemicals, but it dissolves under the action of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid. The alkali resistance of nylon fibers is worse than that of nylon fibers. It will turn yellow in hot dilute alkali and cold concentrated alkali solutions and be destroyed immediately in hot concentrated alkali solutions.

Polyacrylonitrile is insoluble in acrylonitrile, but the copolymerization of acrylonitrile with methyl acrylate and other second monomers improves the solubility. It can be soluble in sodium thiocyanate, dimethylformamide and other solvents for homogeneous solution polymerization.

In the solution polymerization of acrylonitrile, there are many chain transfer reactions. Because of the presence of solvent, the chain transfer of macromolecular radicals to solvent results in the inhibition of macromolecular branching. Therefore, the solvent with appropriate chain transfer constant is generally chosen, and isopropanol or ethanol is used as the regulator.