1986 Fiscal Year Final Research Report Summary
Studies on Improvement of Performance of Composite Materials by Microfibrillation of Aramid Fibers
| Project/Area Number |
60850161
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子物性
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| Research Institution | KYUSHU SANGYO UNIVERSITY |
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Principal Investigator |
TAKAYANAGI MOTOWO KYUSHU SANGYO UNIVERSITY,FACULTY OF ENGINEERING,PROFESSER, 工学部, 教授 (40037643)
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| Co-Investigator(Kenkyū-buntansha) |
SOEJIMA YASUHIRO KYUSHU SANGYO UNIVERSITY,FACULTY OF ENGINEERING,ASSISTANT, 工学部, 助手 (10179377)
UETA SHIGEYUKI KYUSHU SANGYO UNIVERSITY,FACULTY OF ENGINEERING,ASSISTANT, 工学部, 助手 (90069576)
YONEMITSU TADASHI KYUSHU SANGYO UNIVERSITY,FACULTY OF ENGINEERING,PROFESSER ASSOCIATE, 工学部, 助教授 (00069501)
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| Project Period (FY) |
1985 – 1986
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| Keywords | Aramid / Microfibril / Liquid crystal / Elastica loop test / Cyanoacrylate resin / Composite material / Three-dimensional reinforcement / N-置換ポリ(P-フェニレンテレフタルアミド) |
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| Research Abstract |
Microfibrillated poly(p-phenylene terephthalamide)(PPTA) fibers were prepared by spinning a liquid crystal dope of PPTA and N-substituted ethoxycarbonylmethyl PPTA (I) in 100% sulfuric acid. Iwas removed by dissolving by dimethylsulfoxide (DMSO) to remain microfibrillated PPTA fibers. The dope concentration was 13 wt%, which located in liquid crystal region in a phase diagram of temperature and concentration. The purpose of research is to improve the disadvantage of Kevlar being weak to the buckling by compression. By reducing the stress-concentration in bending by using microfibrillated PPTA fibers, the improvement of the composite was pursued. To survey the effectiveness of microfibrillation of filament, an elastica loop test was adopted, with which the ratio of long axis length A to short axis length B for a filament loop is plotted against A. Unfibrillated monofilament buckled at 2 mm of A, while microfibrillated PPTA fibers did not buckle as far as the resolution of polarization microscope allows. Fiber composites of microfibrils with polycyanoacrylate were brittle, while the one with normal fibers was further elongated and yielded. Thus , it was impossible to discern the effectiveness of microfibrillation in composite. The intermicrofibrillar space is conceived to form the defects for fracture. By using microfibrils of PPTA prepared by pouring the sulfuric acid dope of PPTA into water stirred by a homogenizer, three-dimensional reinforcement of composite with epoxy resin succeeded. The composite of partially carboxymethylated PPTA and epoxy was superior to the use of straight PPTA. Especially, hybrid composites of microfibrillated PPTA and N-substituted one were more superior to the one of homogeneously substituted PPTA.
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