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 crosslinking agents are formaldehyde-based N-methylol reagents, such as dimethyloldihydroxyl-ethyleneurea (DMDDHEU). 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 polycarboxylic 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.