Polyacrylonitrile modified fiber is also called modified polyacrylonitrile fiber. Synthetic fiber made of linear polymer copolymer containing 35%~85% acrylonitrile monomer. The United Carbide Company of the United States began its industrial production in 1948, with the trade name Dynel.

There are mainly two types of modified polyacrylonitrile fibers produced in the recent industrial production: fibers made of copolymer of acrylonitrile and vinyl chloride; The fiber is made of the copolymer of acrylonitrile and vinylidene chloride, namely vinylidene chloride polyacrylonitrile fiber. These two types of modified polyacrylonitrile fibers are sometimes collectively referred to as nitrile chloride fibers, which have good flame retardancy.

The performance of polyacrylonitrile fiber is very similar to wool, with good elasticity. When it is stretched by 20%, the resilience can still be kept at 65%. It is fluffy, curly and soft, and its warmth retention is 15% higher than that of wool. It is called synthetic wool. The strength is 22.1~48.5 cN/tex, which is 1~2.5 times higher than wool. It has excellent light resistance. It can be used as curtain, curtain, tarpaulin, and cannon coat after being exposed to the sun for one year. It can resist acid, oxidant and general organic solvent, but has poor alkali resistance.

Acrylic fiber is called artificial wool. It has the advantages of softness, bulkiness, easy dyeing, bright color, light resistance, anti-bacterial, and worm resistance. It can be pure spun or blended with natural fibers according to the requirements of different uses. Its textiles are widely used in clothing, decoration, industry and other fields.