PAN films were prepared by either isothermal heating or double diffusion to expel the solvent in the polymer solution. We used X-ray diffraction

FT-IR

UV spectrometer to investigate the effect of the polarity of the precipitant on the crystallization of PAN in the solutions. The results show that in the process of solidification

the effect of precipitant on PAN crystallization is achieved by the close association between precipitant and cyanogroup. The stronger polarity precipitants hold

the stronger association they form. Therefore

polymer chains are restricted more tightly to block the crystallization of PAN polymers. Addition of electrolyte can help to weaken the association and to improve PAN crystallinity.