EFFECT OF NORMAL ALCOHOLS AND ISO-OCTANE ON TETRACHLOROETHYLENE DYEING OF POLY (ETHYLENE TEREPHTHALATE)

The effects of normal alcohols and iso-octane on the dyeing properties of polyethylene terephthalate (PET) films from tetrachloroethylene (PCE) liquors have been examined in respect to dye diffusion coefficients, saturation values and partition coefficients, etc.The results are summarized as follows;(1) By addition of the alcohols, the diffusion coefficient of Disperse Red 4 in PET increased and reached a maximum at around 20-40vol.% of alcohols added. However, the saturation value and partition coefficient of the dye on PET decreased and showed minima at around 20-40vol.% of the alcohols.The content of the alcohols in PCE, at the maximum or minimum values, decreases with carbon number of the alcohol.The larger change in the diffusion coefficient, saturation value and partition coefficient is observed with the smaller carbon number of the alcohol.On the contrary, iso-octane added in PCE for comparison has practically no effect on the dyeing.(2) The change in the dyeing properties of PET produced by the addition of alcohols can be correlated with the swelling and the plasticization of PET, in addition to the increased solubiities of dye in the dye bathes.