| Summary: | 碩士 === 中國文化大學 === 應用化學研究所 === 87 === Recently , environmental protection is becoming importance.The organic solvent used as a diluent for the resin is gradually replaced by water,a nonpollutant solvent.For this reason , the development of water-based polyurethane(PU) resin becomes important at present.
The reaction of toluene diisocyanates with 4-Hydroxycoumarin or 7-Hydroxycoumarin and other additives to form the structure of fluorescent-dye polyurethane ionomer has been proven by FT-IR spectra.The experimental results show that the surface tensions of 4-Hydroxycoumarin or 7-Hydroxycoumarin solution appear to decrease with increasing the concentration of 4-Hydroxycoumarin or 7-Hydroxycoumarin .
It also indicates that the viscosity of 4-Hydroxycoumarin or 7-Hydroxycoumarin solution is seen to increase with an increase in the concentration of 4-Hydroxycoumarin or 7-Hydroxycoumarin .This is the result of increased free volumes of 4-Hydroxycoumarin molecule or 7-Hydroxycoumarin molecule .
In addition, the number average particle sizes of fluorescent-dye polyurethane ionomer solution appear to increase with increasing the concentration of 4-Hydroxycoumarin or 7-Hydroxycoumarin . Since the interaction between hydrophilic groups of fluorescent-dye polyurethane ionomer molecules themselves becomes strong , therefore , the free volumes of these molecules are considered to be increased , This may be the reason to explain why the viscosity to rises .
The tensile strength and modulus (100%) of self-cured film of fluorescent-dye polyurethane ionomer are seen to increase with increasing the concentrations of 4-Hydroxycoumarin and 7-Hydroxycoumarin . This is because increased hydrophobic groups of fluorescent-dye polyurethane ionomer will strengthen the capability of cross-linking for this ionomer film . For the elongations of fluorescent-dye polyurethane ionomer film , it appears to increase with increasing 4-Hydroxycoumarin or 7-Hydroxycoumarin concentration , as a result of the intermolecular and intramolecular interactions of this ionomer molecule.
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