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Structure and dynamics of MG rubber studied by dynamic mechanical analysis and solid-state NMR

✍ Scribed by M. C. Senake Perera


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
173 KB
Volume
37
Category
Article
ISSN
0887-6266

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✦ Synopsis


Methyl-methacrylate-grafted natural rubber was prepared by free radical polymerization of methyl methacrylate in natural rubber latex, and their structure and dynamics were investigated by dynamic mechanical analysis and solid-state nuclear magnetic resonance (NMR). Samples were prepared by chemical initiation and highenergy radiation. The changes of glass transition temperature and tan ␦ max with different total poly(methyl methacrylate (PMMA) content are reported. The effect of the change in composition in copolymers on tan ␦ peak width, tan ␦ max, and area under the tan ␦ curve are used to understand the miscibility and damping properties. Solid-state 13 C-NMR measurements were carried out to determine several relaxation time parameters, such as rotating frame and laboratory frame proton and carbon relaxation times. Cross polarization times and carbon relaxation times were interpreted based on the changes in the molecular motion. Proton relaxation times were interpreted based on the heterogeneity of the matrix. Results confirmed phase separation and a presence of an interfacial region.


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