INVESTIGATION ON POLYNOSIC FIBER

Abstract

Changes in the fine structure of polynosic fiber (Shin-Teramomen), regular type rayon and modified type high tenacity rayon (Tire yarn), by treating with NaOH solution of various concentrations, are discussed.The results obtained as follows.1) Untreated and diluted NaOH solution treated polynosic fiber show less degree of expansion in the cross-section area at wet state than the degree of water absorption, but they show much the same by concentrated NaOH treatment.2) Polynosic fiber does not increase in crystallinity (by the X-ray method) with NaOH concentration, but increase in crystallinity by iodine absorption and density method. The increase in the density may be caused by the decrease of void in the fiber. Regular type rayon and tire yarn which have a number of unstable crystals show increase in crystallinity by X-ray, acid-hydrolysis, iodine absorption and density method.3) Both length and width/thickness of crystal in tire yarn by treatment with NaOH solution increase, but regular type rayon and polynosic fiber show only increase in length.4) Polynosic fiber has the character in which disorder of plane orientation of (002) and (101) increases in same ratio by the treatment with NaOH solution, but (002) plane of regular type rayon and tire yarn disorient faster than (101) plane, This is due to the difference between random and concentric circular orientations in the planes of crystal formed during the regeneration.