2007 Fiscal Year Final Research Report Summary
Variable Environment NMR Study of the crystallization of polymers
| Project/Area Number |
17550184
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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 |
Polymer/Textile materials
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| Research Institution | Gunma University |
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Principal Investigator |
YAMANOBE Takeshi Gunma University, Graduate Course of Engineering, Professor (40183983)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Polymer structure and properties / crystallization / NMR / Variable environment |
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| Research Abstract |
The crystallization of polymers is very important for the processing of polymers and the physical properties of processed materials. The real- time analysis of crystallization process by pulsed NMR method is invaluable. In this study, the improvement of NMR probe was carried out in order to enhance the sensitivity and the NMR probe is applied to investigate the crystallization mechanism of the some polymers. The improved NMR probe gained the sensitivity of 20 times. The nascent polypropylene structure and crystallization mechanism is investigated. From the results, it was found that the size of crystalline region is extremely small in the nascent polypropylene. The crystallization mechanism of MXD6 nylon was investigated. It was found that the fastest crystallization temperature was 170 C and the mechanism of crystallization depends on the crystallization temperature. On the first stage of the crystallization, the local hydrogen bond network is formed. On the second stage of the crystallization, the conformation of MXD6 methylene part changes and the lamellae grows. The crystallization of polycarbonate is also investigated. Usually, polycarbonate is amorphous polymer, however, PC crystallizes from solution when the solvent is very slowly evaporated. The degree of crystallization is estimated by NMR method. The molecular mobility of polyethylene is investigated during stretching. From the results, the method for estimation of entanglement of polymer chain is presented.
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