ENZYMATIC AND ACID-HYDROLYSIS OF COTTON CELLULOSE AFTER SLACK AND TENSION MERCERIZATION

The effect of enzymatic hydrolysis and acid hydrolysis on slack and te nsion mercerized cotton yarn has been investigated and compared to the effect on the nonmercerized starting sample. Splitting of the glycosi dic bond of cellulose occurs with both types of hydrolysis. When yarn tensile strength was used as a measure of degradation, enzymatic hydro lysis had the largest effect on the cellulose if the fiber had been sl ack mercerized, while acid hydrolysis proceeded faster when the materi al was not mercerized. The intrinsic viscosity of the product did not change markedly after the enzyme treatment, irrespective of whether th e fiber had been mercerized or not. In contrast, in the case of acid h ydrolysis, the intrinsic viscosity of the product decreased in the ord er of slack mercerized > tension mercerized > nonmercerized when a pre treatment had been given. The weight loss during the acid treatment wa s minimal compared to that during enzymatic hydrolysis. Morphological changes such as cracks and peeling due to the enzyme treatment were fo und to vary depending on the starting sample. Photodegradation of the enzyme-treated products was found to be slightly accelerated only afte r tenSion mercerization combined With long incubation times and decele rated to a small extent after slack mercerization. No significant addi tional surface damage could be detected after exposure to ultra-violet light.