Mechanical Strength of Durable Press Finished Cotton Fabric: Part III: Change in Cellulose Molecular Weight

Durable press finishing processes are commonly used in the textile industry to produce wrinkle-free cotton fabrics by crosslinking cotton cellulose. The most common crosslink ing agents are formaldehyde-based N-methylol reagents, such as dimethyloldihydroxyl ethyleneurea (DMDHEU). In recent years, multifunctional carboxylic acids have been employed as nonformaldehyde durable press finishing agents. In this research, we use a multiple angle laser light scattering photometer to measure the change in cellulose molecular weight as a result of cotton cellulose depolymerization caused by a polycar boxylic acid, a Lewis acid used as a catalyst for DMDHEU, or their combination. Cellulose depolymerization takes place on the fabric treated with a polycarboxylic acid or a Lewis acid. The combination of Lewis and polycarboxylic acids as an "activated" catalyst for DMDHEU causes more severe cellulose depolymerization. Our results indicate a direct correlation between tensile strength loss of the treated cotton and the molecular weight of cellulose.