| Summary: | 碩士 === 國立勤益科技大學 === 化工與材料工程系 === 99 === This reseach investigates the different types and the different proportion toughening agents in the epoxy resin and to prepare the composite materials. From these composites we further evaluate its thermal ， mechanical properties and surface morphology after the impact test.
The experiments were divided into three parts: (A) we use organic-inorganic hybrid microspheres and organic double layer core-shell microspheres to investigate the toughness modification and fracture behavior of epoxy resin; (B) we looked into the toughening effect and its physical properties through the swelling phenomenon of TPU microspheres; (C) these thermoplastic polymer was evaluates to prove the effect on toughening.
Commercial available Hollow-glass bubbles (IM-30K) and organic microspheres (H-50F) were used as the cores of experimental toughening agent, covered with PC-PET microspheres for part (A), TPU microspheres for part (B), and the thermoplastic polymer of TPU、 PC and PET for part (C), respectively. The experimental results of part (A) indicate that the toughness of epoxy resin will be lowered due to the reduction of its shear deformation ability. It is also found that the size of microspheres is the decisive factor to the craze depth of hollow glass bubbles.
Second, experiment part (B) reveals that larger microspheres of TPU(200~400μm) are more effective in toughening of epoxy resin，indicating that the swelling phenomenon helps improve the toughening performance. In addition, the craze occurs inside the TPU microspheres as a result， they have the ability to withstand the stress and absorb the destructive energy.
Finally from the last part， it was observed that the lack of rapid deformation ability of PC and PET fails to toughen the epoxy resin even though the size of microspheres is increased. While TPU particles exhibit such ability to absorb the impact fracture energy, it is found that the major energy absorbing mechanisms depend on the plastic deformation and matrix shear deformation when TPU microspheres are larger than 200μm.
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