Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
|Research Institution||Kyushu University|
TAKAHASHI K. Kyushu University, Research Institute for Applied Mechanics, 応用力学研究所, 教授 (10010795)
アルバート F.イー ミシカ゛ン大学, 材料工学科, 教授
OKAMOTO Y. Sumitomo Chemical Co., Ltd., Chiba Research Lab., 千葉研究所, 主任研究員
安田 浩 東洋紡績(株), 総合研究所, 第二研究部長
中川 英昭 三菱油化(株), 高分子基礎研究所, 主任研究員
崔 洛三 九州大学, 応用力学研究所, 助手 (10227340)
桜田 泰弘 九州大学, 応用力学研究所, 助手 (50038543)
ARAKAWA K. Kyushu University, Research Institute for Applied Mechanics, 応用力学研究所, 助教授 (00151150)
YEE A. F. The University of Michigan, Dept. Materials Science and Engineering
YASUDA H. Toyobo Co., Ltd., Research Institute
CHOI N. S. Kyushu University, Research Institute for Applied Mechanics
NAKAGAWA H. Mitsubishi Petrochemical Co., Ltd., Polymer Science Lab.
SAKURADA Y. Kyushu University, Research Institute for Applied Mechanics
イー F.アルバート ミシカ゛ン大学, 材料工学科, 教授
イー アルバートF. ミシガン大学, 材料工学科, 教授
|Project Period (FY)
1990 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 1991 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1990 : ¥2,300,000 (Direct Cost : ¥2,300,000)
|Keywords||Polymer Alloys / Multi-Phase Polymers / Fracture Toughness / Caustic Method / Moire Interferometry / Bi-Modal HIPS / ゴム強化ポリマ- / 衝撃破壊 / 多相系ポリマ- / ハイインパクトポリスチレン / コ-スティック法 / クレイジング|
In this investigation multi-phase polymers were studied concerning (1) application of photomechanics to fracture toughness evaluation, and (2) micromechanical analysis based on observations through various types of microscopes. An international seminar on impact fracture of polymers was organized in July, 1991, in Fukuoka.
1. A study on fracture toughness evaluation using the optical method of caustics in reflection
(1) Caustics were successfully obtained in reflected optical setup from PPO alloys which had a surface finishment of polishing and metalevaporation thereafter.
(2) The fracture toughness values were evaluated by the reflected caustics for the first time based on a formula given by Rosakis et al. They were similar to those given by a formula based on the linear elastic fracture mechanics (LEFM) for PPO alloys in a temperature range -60 - -40ﾟC. At higher temperatures, the caustic method could give toughness data which was correctly temperature dependent, while values from LEFM
were almost unchanged and were unable to exhibit the temperature dependency.
2. Application of the moire interference method to deformation measurement around a tensile crack was successfully made for PPO alloys under room temperature. A limit, 40% of a fracture initiation point for precracked tensile specimens, was found, where the linear fracture mechanics can well be applied.
3. Toughening mechanism of rubber-toughened polymers
(1) Importance of cavitation of rubber particles
The importance of cavitation of rubber particles has been elucidated for the toughening mechanisms. When rubber particles are cavitated, microvoides are resulted and they become origination sites of micro-shear deformation, which is energy consuming, and therefore, contributes to the toughness increase. This supposition has been verified by a pressure test. Tensile specimens of rubber-toughened and non-toughened epoxy were uniaxially loaded under hydrostatic pressure which constrained cavitation. Strength of rubber-toughened specimens were smaller than that of non-toughened, and little cavitation was found to have occurred in the former.
(2) Toughening mechanism of bi-modal HIPS
Bi-modal high impact polystyrene has been found to be tougher than mono-modal one for the same rubber particle contents. The mechanism was studied and was found that longer crazes are bigger in number in the former. The FEM analysis was made for both systems and gave an result which confirmed that longer crazes tended to be generated in the bi-modal system.
4. The International Seminar on Impact Fracture of Polymers was organized by the present research group and held in July 22-24, 1991 in Fukuoka. Totally 99 persons attended, among them 17 being foreigners. The Proceedings, paged 454, will appear from the Kyushu University Press in April 1992. Less