1993 Fiscal Year Final Research Report Summary
Cristalization of Polymers and Development to the Texture
| Project/Area Number |
04302055
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子構造物性(含繊維)
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
MIYAJI Hideki KYOTO UNIV., Fac. Sci., Ass. Prof, 理学部, 助教授 (90025388)
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| Co-Investigator(Kenkyū-buntansha) |
OKUI N Tokyo Inst. Tech., Fac. Eng., Prof., 工学部, 教授 (20111651)
SAITO Y Keio Univ., Fac. Sci. and Eng., Ass. Prof., 理工学部, 助教授 (20162240)
MIYAMOTO Y KYOTO UNIV., Fac. Int.Human Std., Ass. Prof., 総合人間学部, 助教授 (00174219)
OHIGASHI H Yamagata Univ., Fac. Eng., Prof., 工学部, 教授 (90185372)
TODA A KYOTO UNIV., Fac. Sci., Instructor, 理学部, 助手 (70201655)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Polymer Crystals / Crystal Growth / Equilibrim Melting Temperature / Crystalline Texture / Morphology / Regime Transition / Nucleation / Thin Film |
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| Research Abstract |
1. The equilibrium melting point T_m^o is a critical quantity in polymer cristallization since crystal growth is essentially described not by the crystallization temperature itself but the super cooling. For polystirene the T_m^o was found to be higher than the reported value by 20K.The precise phase diagram of polyethylene has been determined including the triple point among liquid, the orthorhombic and hexagonal solids. 2. The crystal core in lamellae of polystirene has been found to be very thin. These lamellae increase their number and Branch through screw dislocations to form spherulites. Direct observation of the crystal growth in an electron microscope was done on polystirene thin films ; the melt around the growth face is thinner than the film and causes a decrease in growth rate. 3. Detailed experiments on the melt growth of polyethlene showed that the transition from regime I to II gives rise to a morphological transition from a hexagonal to a lenticular crystal shape. 4. Rigid polymersincluding polythtrafluoroethylene usually crystallize to form fibrils parallel to the chain axis without any foldings. However, increasing the crystallization temperature causes the formation of fibris, the axis of which are perpendicular to the chain axis. 5. The fluoride polymers, poly (vinylidene fluoride) and its copolymer with trifluoroethylene ara ferroelectric, and domain structre due to electric polarization has been observed for the first time ; the polymer ferroele13EA\ : ctrics belongs to the same category as the non-polymeric one. 6. The lammelar structre and spherulite formation in several mixtures (PEO/PMMA, PVDF/PMMA, PCL/PVME) were investigated, and it is concluded that diffusion of the crystalline polymer through uncrystallizable polymer controls the morphology. 7. Theoretical investigation and simulation on the shape of polymer crystals and lamellar thickness could reproduce the experimental results qualitatively and has reached
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