著者

栄永 義之 藤田 博

出版者

一般社団法人 日本レオロジー学会

雑誌

日本レオロジー学会誌 (ISSN:03871533)

巻号頁・発行日

vol.12, no.3, pp.136-141, 1984-09-20 (Released:2012-11-20)

参考文献数

35

被引用文献数

4

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Literature data on the self-diffusion coefficient Ds of linear polymers in bulk and solution have been reexamined. The major conclusions are as follows:(a) The currently accepted relation for Ds as a function of polymer molecular weight M and concentration cp, i. e., Ds∝M-2,p-1.75 (i) is not exactly followed by the data, though it is usually taken as evidence for the reptation motion of a polymer chain assumed in the tube theory and also for the scaling theory.(b) The experimental data examined suggest that Ds tends to obey the relation Ds∝M-2.5 (ii) for M>Mc, the critical molecular weight for the onset of entanglement, and Ds∝M-1 (iii) for M<Mc, with a smooth transition between the two regions. Equation (ii) is consistent with the relation expected from viscoelastic data on polymer concentrates.