2005 Fiscal Year Final Research Report Summary
Development of impact-resistant polymeric materials by nano structure control
| Project/Area Number |
15360059
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
ARAKAWA Kazuo KYUSHU UNIVERSITY, Research Institute for Applied Mechanics, Professor, 応用力学研究所, 教授 (00151150)
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| Co-Investigator(Kenkyū-buntansha) |
TODO Mistugu KYUSHU UNIVERSITY, Research Institute for Applied Mechanics, Associate Professor, 応用力学研究所, 助教授 (80274538)
MORITA Yasuyuki KYUSHU UNIVERSITY, Research Institute for Applied Mechanics, Research Associate, 応用力学研究所, 助手 (90380534)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Polymers and composite materials / Nano- and micro-structure / Impact resistance / Mechanical property / Fracture behavior / Fracture toughness / Morphology / Fracture mechanism |
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| Research Abstract |
New experimental techniques for evaluating the impact fracture toughness of polymers and composite materials were developed. The validity and adaptability of the techniques were then examined by testing the various materials including biodegradable polymers and composites. The techniques were also applied to these materials which changed their structures in the nano- and micro-scopic level. The impact fracture mechanism was then investigated.
The impact fracture mechanism was studied by measuring the dynamic response and residual deformation of the specimen materials after fracture. The dynamic and non-elastic effects were analyzed, because the fracture toughness of polymers is generally dependent on both the viscosity of material and the dynamic effect due to the crack propagation. These two effects were taken into consideration in the impact analysis. The external work applied to the specimen was partitioned into three components : the elastic energy, non-elastic energy, and fracture energy for creating a new fracture surface. The energy release rate was estimated to examine the impact fracture mechanism in detail.
The structures of biodegradable polymers and composite materials were modified by annealing, blending and/or mixing with different biodegradable materials. The fracture toughness of the specimens was measured under static and impact loadings, and the morphology of the fracture surfaces and damage zone ahead of the crack front were also examined using polarizing microscopy and scanning electron microscopy. As a fracture parameter that controls crack growth, the energy release rate was determined using a load and displacement diagram, and it was shown that the fracture toughness can be clearly improvable by controlling the structures by nano- and micro-scopic level.
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