| Summary: | 碩士 === 逢甲大學 === 纖維與複合材料學系 === 105 === Epoxy resin was brittle after hardening into a three-dimensional network structure. The force would produce cracks, and growth rapidly. So it need to improve the toughness and mechanical properties by modification. In this time, the epoxy resin was modified by adding chain extending agent and different proportions of nano-silica. And using DSC to examine the effect of modifiers on the glass transition temperature (Tg). The mechanical properties of epoxy resin /glass fabric composite laminate were investigated by Mode I fracture toughness, Mode II fracture toughness, flexural properties and interlaminar shear strength (ILSS). The Zeta Potential Analyzer was used to understand the different of nano- silica’s particle size. And the Field Emission Emission Scanning Electron Microscope (FE-SEM) to observe the failure morphology on the fracture surface of after fracture toughness test.
With the high speed mixer and three-roll miller which can reduce the phenomenon of nano-silica agglomeration. Based on the DSC determined showed that glass transition temperature of cured resin system decreased with increasing of the chain extending agent. Because the soft chain caused by the increase in free volume. And when the nano-silica added in to the resin system, it would increasing the glass transition temperature. The flexure properties and ILSS all showed the same trend like glass transition temperature. The Mode I and Mode II fracture toughness of laminate enhance 55.7 % and 47 % with content 5 wt% of chain extending agent and 8 wt% of nano-silica. According to the FE-SEM observation found that with the increase of toughening agent, the broke section would become roughly.
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