Interactions of Nonaqueous Solvents with Textile Fibers

Abstract

The kinetics of the shrinkage of a drawn polyester yam in a number of organic solvents, including toluene, acetonitrile, dimethylformamide (DMF), trichloroethylene, perchloroethylene, and tetrachloroethane, were investigated at several temperatures. The shrinkage process proceeds at a maximum rate after an induction period which is believed to be associated with diffusion of the solvent into the fiber structure. The temperature dependence of the maximum shrinkage rate follows the Arrhenius relationship. Activation energies ranging from 23 to 36 kcal/mol were found for the various solvents, compared to 13 kcal/mol for the shrinkage in the dry state. The equilibrium or final shrinkage values were found to increase linearly with temperature, thereby allowing extrapolation to a zero-shrinkage temperature. This latter value is believe to be an approximation of the glass-transition temperature of the polyester-solvent system. Horizontal shifting along the temperature axis of the curves relating final shrinkage to temperature resulted in a master shrinkage curve for the solvents investigated. The extent of shifting is also believed to be associated with the glass-transition temperature of the system.