Influence of Spinning Dope Additives and Spin Bath Temperature on the Structure and Physical Properties of Acrylic Fibers

Abstract

We have studied the effect of spinning dope additives and spin bath temperatures on the structure and properties of wet spun acrylic fibers. The dope additives were secondary cellulose acetate, polyvinyl pyrrolidone, polyvinyl acetate, and glycerol. Amounts of 5% (w/w) of each of these were added to the spinning dope of acrylonitrile vinyl acetate sodium methallyl sulphonate (92.7:7.0:0.3 by wt) terpolymer, and wet spun using 45:50 (v/v) of dimethyl acetamide : water, varying the spin bath temper ature from 10 to 60°C. Fibers with 5% secondary cellulose acetate as an additive exhibited low density values, highest moisture regain (2.6% against 1.6% of the parent acrylic fiber), and a three- to four-fold increase in water retention values. The tenacity was greatest in fibers with 5% polyvinyl acetate, added and spun at a 45°C spin bath temperature. We also studied the microstructure of the protofibers and the final fibers using both optical and elecqon microscopy for a better understanding of the effect of spin bath temperature on physicomechanical properties.