| Summary: | 碩士 === 國立高雄應用科技大學 === 化學工程系碩士班 === 96 === Curable acrylated cresol novolac epoxy resin derivatives with different structural features were synthesized, and the relationship between the surface free energy and different structures of curable resin were studied through contact angle measurement and surface free energy calculation.
The uv/themal-curable acrylated (or acetylated) cresol novalac epoxy resins (ACNER, AcNER, AmixCNER) containing vinyl and hydroxyl groups were first obtained from the esterification of saturated or unsaturated monocarboxylic acid with N-695 cresol novalac epoxy resin (CNER). Carboxylated curable resins (acidified ACNER; HACNER) containing vinyl, hydroxyl and carboxyl groups were then obtained by esterification of hydroxyl groups of ACNER with saturated or unsaturated polybasic acid anhydride, and acetylated curable resins (capped ACNER; CACNER) mainly containing vinyl groups were obtained by esterification of hydroxyl groups of ACNER with monobasic acid anhydride. The esterification and structure of synthesized resins were characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR).
The curable resins films for contact angle measurement were prepared by coating and then drying. The cured films were obtained after UV irradiation. The photo-curable properties of synthesized resins can be characterized by DSC and FTIR.
Surface free energy of curable resins (ACNER、HACNER、CACNER) before and after curing was respectively calculated using two-liquid geometric and three-liquid acid-base methods through contact angle measurement, and evaluated in terms of various surface free energy components (γd, γp, γLW, γ－, γ+, γAB).
The experimental results showed that an increase in the amounts of hydroxyl group of the derivative resins results in increase in the polar component of surface free energy (γp, γ－), indicating the increase of polarity of resin surface. The surface of curable resins (ACNER、HACNER、CACNER) surface was found to be monopolar (Lewis base，γ－). Further, the Lewis acid component (γ+) of the surface free energy of curable resins increases with an increase of carboxyl group content, indicating the increasing electron accepting character of the surface. Furthermore, results also showed that the γ－, γp, and γs of curable resins decrease with the increase of density of crosslink through UV curing.
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