APPLICATION OF WILLIAMS-LANDEL-FERRY EQUATION TO THE DIFFUSION OF DISPERSE DYES IN POLYESTER

Abstract

1. The applicability of equation (1), obtained by the author, to the diffusion of many disperse dyes in the aqueous dyeing of polyester rolled film was investigated using the data published in literature.
where a_T, D and T are shift factors, diffusion coefficient and absolute temperature, respectively. The subscript s indicates the values at a refference temperature. The square of the diffusion layer, l, was used in place of the diffusion coefficient. It was found that eq. (1) is applicable to the diffusion of many dyes practically used, and that log l_s² decreases with the increase in the molecular size of the dyes.
2. Eq. (1) was also found to be applicable to the dyeing of polyester in tetrachloroethylene (TCE) as it was in aqueous dyeing. The increase in the diffusion coefficient and the smaller dependence on temperature in the TCE dyeing than in the aqueous dyeing were explained by the lowering of T_s due to the lowering of the glass transition point of the polyester in TCE.