| Summary: | 碩士 === 中國文化大學 === 應用化學研究所 === 88 === The reaction of toluene diisocyanate with polyester , antioxidant , weather-resistant and other additives to form the conformation of antioxidant , weather-resistant polyurethane resin has been proven by FT-IR spectra . Experimental results show that the viscosity of antioxidant , weather-resistant polyurethane resin appears to increase with increasing the concentration of weather-resistant agent . This is because the intermolecular interaction between PU resin molecules may make the free volume of PU resin with Tinuvin P become large . Thus , the viscosity of this resin molecule increase . On the other hand , the viscosity of antioxidant , weather-resistant PU resin molecule is seen to decrease gradually with increasing the concentration of antioxidant agent , as a result of decreased free volume resulting from intramolecular interaction of PU resin molecule itself . This intramolecular interaction may make the molecule form compact conformation or micelle-like structure , thus causing the viscosity of PU resin to decrease .
The experimental results indicate that for self-cured film of PU resin both tensile strength and modulus appear to decrease with increasing the concentration of Tinuvin P , while the elongation and the modulus under sun light are seen to decrease with increasing the concentration of Tinuvin P , as a result of decreased crosslinking resulting from strong intramolecular interaction . Contrarily , the tensile strength of self-cured film of PU resin molecule increases with increasing the concentration of antioxidant agent . This is be due to more functional groups linked to the backbone of PU resin molecule which may strengthen the capability of crosslinking .
The elongation for self-cured film of PU resin molecule appears to increase with increasing the concentration of weather-resistant agent , and , Under sun light , this elongation is seen to increase with an increase of the concentration of weather-resistant agent as well . This is the result of the formation of less compact conformation . Similarly , the elongation of this resin is seen to increase with increasing the concentration of antioxidant agent , as a result of intermolecular interaction stranger than intramolecular interaction for PU resin molecule.
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