Investigation of Acrylonitrile Graft Copolymerization onto Wool Fibers

Graft copolymerization of acrylonitrile(AN) onto the wool fiber was initiated by potassium permanganate-oxalic acid redox system. The influence of sodium hydroxide pretreatment, dosage of monomer, reaction time, concentration of initiators and temperature to graft percentage, graft efficiency and tensile strength of fiber were investigated. Fourier transform infrared spectroscopy(FTIR) and scanning electron microscopy(SEM) results showed that potassium permanganate-oxalic acid redox system have a good ability to initiate acrylonitrile grafting copolymerized onto the wool fiber. The surface of wool became rough and coated well with grafted poly(acrylonitrile). Graft percentage increased with the increasing of treatment time by sodium hydroxide solution, but the tensile strength of wool fiber decreased. When monomer dosage was increased, Graft percentage would be increased, but graft efficiency decreased. Graft percentage was increased to equilibrium with the increasing of reaction time. The tensile strength and the thermostability of the grafted wool fibers were increased.