Improved Light and Weather Resistance of Cotton Resulting from Mercerization

Abstract

Comparative exposures of mercerized and unmercerized cotton to light and to weath ering brought out anomalous effects in the breakdown of cotton cellulose. There was less deterioration of the mercerized cotton, as measured by the ability of the fabric to resist rupture by tension (measured by breaking strength), but at the same time, more degradation (as determined by fluidity measurements), indicating a reduction in average degree of polymerization of the cellulose. These observations are consistent with reports in the literature that mercerized cotton is somewhat more susceptible to oxidation and to hydrolysis than comparable un mercerized cotton. The behavior in exposure to light evidently is part of a general phenomenon, because higher fluidities have been ohserved for the chemically reactive mercerized cottons under conditions where the strength losses for mercerized and un mercerized cottons were equal. The higher retention of strength by the mercerized cotton may represent a significant advantage, because it promises a longer service life of mercerized goods when deteriora tion occurs mainly from exposure to sunlight. When ordinary unmercerized cotton has lost half strength, corresponding mercerized cotton can be expected to last for 14 to 13 longer before reaching that level.