The Kinetics of the Adsorption of Different Ester Type Polyols toward the Poly Ethylene Terephthalate Fiber

Abstract

The adsorption kinetics of different ester types polyol toward polyethylene terephthalate (PET) fibers was studied and the solvent effect, the activation energy, adsorbing rate constant and amount of adsorption temperature and pH or addition of neutral salts were investigated in this paper. We found that the adsorption capacity of ester type polyols with double benzene rings (PTET400 and PTETE400) toward PET fibers is better than that of polyols with a single benzene ring (PT400 and PTE400). The adsorption for all polyols showed a two-step adsorption phenomenon. The first step is instant adsorption and the second step is diffusion adsorption. The diffusion adsorption is a first-order adsorption. The adsorption curves of diffusion adsorption for the same polyols under different LR (liquor ratio) of polyol aqueous solution toward PET fabrics were to cross in one point, when t=0. The adsorption rate (K) of polyols showed a linear relationship with the LR (liquor ratio) of solution. As for the absorption amounts, both amounts of instant and diffusion adsorption for all polyols showed a linear relationship with increase in temperature. The instant adsorption amount of the polyols with double benzene rings toward PET fibers is greater than that of polyols with a single benzene ring particularly under a lower pH. The addition of neutral salts had a positive effect on absorption. The order of adsorption activation energy for polyols toward PET fibers is PTE400 > PT400 > PTETE400 > PTET400.