Hydrazine Cross-linking in PAN Films in a Reaction Medium of Aqueous DMF Solution

c2017 The Korean Fiber Society Abstract: The introduction of cross-linking into polyacrylonitrile (PAN) films with hydrazine solutions in a reaction medium of various concentrations of aqueous N,N'-dimethylformamide (DMF) solution was studied. The effect of the DMF concentration in the reaction medium, hydrazine concentration, reaction temperature, and time on the hydrazine addon and the degree of DMF swelling was investigated. The swelling in the DMF decreased with an increase in the hydrazine add-on, indicating that the modified PAN films became insoluble and swollen in the DMF. Although all the reaction conditions affected the hydrazine add-on, a high temperature of 110 C in a 60 % (v/v) aqueous DMF solution with a 6 % (w/v) hydrazine solution resulted in more effective cross-linking at the same hydrazine add-on values. Analysis of the FTIR and UV-Visible spectra confirmed the introduction of the hydrazine cross-linking. The crystallinity of the modified PAN film reduced with increasing hydrazine cross-linking.