2003 Fiscal Year Final Research Report Summary
Development of Real-Time Analysis Method for Polymer Crystallization
| Project/Area Number |
13650946
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | Gunma University |
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Principal Investigator |
YAMANOBE Takeshi Gunma University, Department of Chemistry, Associate Professor, 工学部, 助教授 (40183983)
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| Co-Investigator(Kenkyū-buntansha) |
UEHARA Hiroki Gunma University, Department of Chemistry, Assistant Professor, 工学部, 助手 (70292620)
KOMOTO Tadashi Gunma University, Department of Chemistry, Professor, 工学部, 教授 (00016643)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Polymer / Crystallization / pulse NMR / Morphology |
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| Research Abstract |
Crystallization of polymers is one of the most important factors for the physical properties of the polymeric material from the point of views of not only the scientic interest but also the processing of material. So far, the behavior of crystallization has been studied for the sample by quenching the material which was crystallized under a certain condition. The purpose of this study is to develop the real-time analysis method for polymer crystallization.
The polymers are produced by the polymerization of monomers as a nascent powder. From the DSC measurements, it has revealed that the crystallinity of the nascent powder of isotactic polypropylene (iPP) is very low compared with the pelletized, melt quenched and melt crystallized iPPs. The peak ratio between the crystalline and amorphous peaks of the nascent iPP for solid state ^<13>C CPMAS NMR at 100℃ is different from those of the pelletized, melt quenched and melt crystallized samples. And also the peak ratio for the nascent powder
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is changed with time at 100℃. From the real-time pulse NMR measurements it is revealed that the mobility of the crystalline phase of the nascent iPP is drastically activated with temperature. Tem micrographs indicate the absence of the lammelae which are usually observed for iPP samples. From these results, it is concluded that the crystalline phase of the nascent iPP is too small to form lammelae and the activation of mobility for amorphous phase simultaneously activate the crystalline phase.
Poly(butylene naphthalate) (PBN) form A and B form dependent on the rate of decreasing temperature. Real-time measurements of non-isothermal crystallization behavior for PBN are carried out. When the temperature is lowered at it 1℃/min, two components are observed for T_2, long and short T_2s. T_2 decreases with temperature drastically. While T_2 does not change at about 280-270℃, when the temperature is decreased at 0.1℃ /min. The ratio of long T_2 increased drastically at 280-270℃. From the real-time measurements, it is concluded that the long time retention of the sample at high temperature induces the nucleation of B form.
It is, therefore, concluded that our real-time analysis is of great importance and promising for the analysis of crystallization mechanisms of polymers. Less
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Research Products
(8 results)
