Processing and Characterization of Fracture Behavior of Hybrid Epoxy Nanocomposite Modified with Polycarbonate

Amini NajafAbadi, Leila | 2016

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 49689 (07)
  4. University: Sharif University of Technology
  5. Department: Characterization and Material Selection
  6. Advisor(s): Bagheri, Reza
  7. Abstract:
  8. Epoxy resins have good mechanical and thermal properties, high chemical resistance and low shrinkage during cure but in spite of these good properties,they are brittle and this limits the usage of them. Adding a second, soft or rigid, phase has been always an effective strategy to improve the toughness of epoxy. Rigid phase used in resins are divided into organic and inorganic. The aim of this study is to increase epoxy toughness, maintaining mechanical properties and study effect of silica and polycarbonate on fracture toughness simultaneously. Mechanical properties including yield strength and elastic modulus are evaluated by pressure test. Additionally fracture toughness and three pointing bending are investigated by toughening mechanisms based on SEM microscopic and TOM. In the first step, the mixtures of epoxy/polycarbonate were prepared by solvent method. DSC and SEM results showed the mixture of epoxy/polycarbonate was totally miscible and the plastic deformation was increased by adding polycarbonate into epoxy. 40% improvement of toughness has been observed in the sample contained 5phrs of poly carbonate. The comparison strength and Tg of epoxy were increased by enhancing polycarbonate percentage while the elastic modulus has not been changed significantly. In the second step of this research, the epoxy nano-composite was modified by polycarbonate. The map of homogenous dispersion of silica in epoxy matrix was provided by EDS-SEM. It was shown that the addition of polycarbonate into epoxy/silica composite limiting the shear yielding of matrix
  9. Keywords:
  10. Silica ; Fracture Toughness ; Epoxy Silica Nanocomposite ; Polycarbonate ; Toughening Mechanism ; Epony Hybride

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