The molecular weight of acrylonitrile/itaconic acid copolymer can be calculated from the intrinsic viscosities of the dilute reaction solutions directly, when the conversion was higher than 90% during the solution polymerization. Because of the sample treatment processes such as film preparing, washing, drying and redissolving were simplified, the analysis time was reduced substantially. The proposed method is more suitable for rapid analysis. The measurement error compared with common method of determination for the copolymer in DMSO by single point method was about 1%.
Free\|radical solution copolymerization of itaconic acid and acrylonitrile was carried out in DMSO at 58～60℃ using azodiisobutyronitrile as initiator.The resulting polymerization solution was spun to form PAN precursors of carbon fibres.The precursors were treated with NiSO 4 aqueous solution at 95℃ on line.The structure and properties of untreated and treated PAN precursors and resultant carbon fibres were characterized by IR,SEM,dynamic viscoelasticity study,stabilization process and so on.It was suggested that carbon fibres developed from modified PAN fibres showed an improvement in tensile strength by about 20%～30% and Young’s modulus by about 5%～10%.
