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.

Synthetic fiber made of polyacrylonitrile or acrylonitrile copolymer containing more than 85% (mass percentage) of acrylonitrile. The common second monomer is non-ionic monomer, such as methyl acrylate and methyl methacrylate, and the third monomer is ionic monomer, such as sodium allylsulfonate.