1993 Fiscal Year Final Research Report Summary
Relationship between Tranlational and Rotational Diffusions of Polymer Chains
| Project/Area Number |
04453106
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子物性・高分子材料（含機械材料）
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| Research Institution | Osaka University |
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Principal Investigator |
ADACHI Keiichiro Faculty of Science, Osaka University Associate Professor, 理学部, 助教授 (00028226)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Hiroshi Faculty of Science, Osaka University Assistant Professor, 理学部, 助手 (90167164)
KOTAKA Tadao Faculty of Science, Osaka University Professor, 理学部, 教授 (20027022)
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| Project Period (FY) |
1992 – 1993
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| Keywords | translation diffusion / rotational diffusion / end-to-end vector / polyisoprene / relaxation time / tube model / Rouse theory / polybutadiene |
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| Research Abstract |
Measurements of the translational diffusion coefficient D and the relaxation time tau for reorientation of the end-to-end vector of polyisoprene (PI) were carried by means of forced Rayleigh scattering and dielectric methods, respectively. From the dielectric relaxation strength we also determined the mean square end-to-end distance <r^2>. From the data of D, tau, and <r^2> over wide range of molecular weight M, the values of a dimensionless quantity Dtau/<r^2> were determined and compared with the Rouse theory and tube model.
In monodisperse polyisoprene, D decreased with increasing M in proportion to M^<-2.8> in the range of 10000 < M < 40000 but the exponent decreased slight in 40000 < M.This behavior does not agree with the tube model which predicts D * M^<-2.0>. In a binary blends in which a trace amount of labeled PI is dissolved in a matrix of non-labeled PIs, D depended strongly on the M of the matrix PI,i.e., D * M^<-1.0> when the M of the diffusant is much higher than that of matrix and D * M^<-2.5> wehn the matrix has much higher M than the diffusant. The former behavior agrees with the Rousse theory. The value of Dtau/<r^2> in the monodisperse system is calpha one order smaller than the prediction of the Rouse and tube models both of which predict Dtau/<r^2> = 1/3pi^2. On the other hand, in the binary blends of low molecular weight matrix, Dtau/<^2> agreed well with the Rouse theory.
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