Physicomechanical Properties of Fibers from Blends of Acrylonitrile Terpolymer and Its Hydrolyzed Products

Acrylonitrile terpolymer containing 92.7% acrylonitrile, 7% vinyl acetate, and 0.3% sodium methallyl sulphonate was hydrolyzed to degrees of hydrolysis of ∼0.104(T 1 B 1 ), ∼0.367 (T 1 B 2 ), and ∼0.450 (T 1 B 3 ), respectively, at 40°C with 5% NaOH. Each of these polymers was blended with the parent terpolymer in a 10:90 ( w/w ) ratio and wet-spun using 45:50 (v/v) dimethyl acetamide : water, varying the spin bath tem perature from 10-60°C. The dope viscosity of the blends increased with the increase in the degree of hydrolysis of the product, which could be attributed to the bulky amide-imide groups. Spinnability was the best in a blend containing T 1 B3. After au toclaving, these fibers showed higher tenacity (174 kN·m/kg) and moisture regain (1.8%) compared to the parent fibers (124 kN·m/kg and 1.3%) and other blends. The influence of the bath temperature on the structure of the protofibers was also investigated.