Structural changes in Tencel by enzymatic hydrolysis

Abstract

The NaOH-, fibrillation-, and cellulase- treated Tencel fabrics were characterized by weight loss, tensile strength, scanning electron microscopy (SEM) analysis, X-ray diffraction analysis, measurements of moisture regain and dye adsorption (K/S value), degree of polymerization (DP), and copper number. Weight loss increased and tensile strength decreased with increase in cellulase concentration and treatment time. At a similar weight loss, tensile strength retentions of the NaOH-pretreated samples were better than those of the NaOH-nontreated samples because of more uniform enzymatic hydrolysis. SEM photographs showed more surface peeling and interfibrillar splitting as enzymatic hydrolysis progressed. Crystalline structure and degree of crystallinity were not much changed by cellulase treatment. As enzymatic hydrolysis progressed, moisture regain and K/S value increased slightly due to increase of specific surface area by fibrils. DP initially decreased as enzymatic hydrolysis progressed and then leveled off. Copper number increased largely at an initial stage of degradation and then decreased gradually. The NaOH-pretreated samples showed higher degree of crystallinity, DP, moisture regain, and K/S value, but lower copper number than the NaOH-nontreated ones. These results were attributed to extraction of short chain molecules in the amorphous region during NaOH pretreatment and change of amorphous region into the open-up structure.