抄録
The equilibrium absorptions of several disperse dyes by Orlon 42 have been investigated at 90° and 100°. The thermodynamic parameters for the transfer of one mole of disperse dye from water to acrylic fiber were calculated. The results are discussed in terms of.
These three new functions are difined as follows: where subscript s stands for the standard dye and subscript i the dye to be compared. Thus are changes in thermodynamic parameters caused by introduction of some substituent in the standard dye. In this study aminoazobenzene has been taken as a standard dye. The free energy increments are functions of the enthalpy and entropy increments, that is any of the substituent effects on the free energy can be separated into effects on the enthalpy and the entropy.
The equation (4) is transformed into the following equation
The term represents the thermodynamic character of the substituent effect.
In dyeing phenomenon the enthalpy and entropy increments have the same signs. So the terms has always a positive sign.
Therefore four possible cases are derived:
The case 1. The term is negative. From the equation (5), it is obvious that the subutituent effect on the free energy is negative and this is due to the energetic situation.
The case 2. The term is positive. In this case the substituent effect on the free energy is positive and this is due to the energetic situation.
The case 3. The term is negative. In this case the substituent effect on the free energy is positive and this is due to the entropic situation.
The case 4. The term is positive. In this case the substituent effect on the free energy is negative and this is due to the entropic situation.
The substituent effects under these treatments are discussed and it was found that “hydrophobic bonding” might be an important factor in the interaction between disperse dyes and acrylic fibers.
