A semi-empirical method for estimating unperturbed dimensions of chain polymers from the intrinsic viscosity-molecular weight relationship
| Autor: | Michio Kurata, Hidematsu Suzuki, Hiroshi Inagaki |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Journal of Polymer Science Part C: Polymer Symposia. 15:409-425 |
| ISSN: | 1935-3065 0449-2994 |
| DOI: | 10.1002/polc.5070150136 |
| Popis: | A semi-empirical method for estimating unperturbed chain dimensions from relationships between intrinsic viscosity M and molecular weight M is proposed. This method is based on combining the Ptitsyn equation of the excluded volume effect with a semi-empirical relation between two expansion factors αη and α for the hydrodynamic radius and the end-to-end distance, respectively, i.e., αη3 = α5/2, which has been suggested by Yamakawa and Kurata. This combination gives ([η]/M1/2)4/5 = 0.786K4/5 + 0.950-K4/5*2/3M1/3 for large α, presumably for a larger than 1.4, Experimental tests are made with viscosity data obtained for polystyrene fractions in trans-decalin, benzene, and butanone and also with those obtained for poly(methyl methacrylate) in various solvents. Light-scattering data by Berry are discussed in the light of present results. The parameter B describing long-range interactions is found to be nonlinearly related to the reciprocal of temperature 1/T, that is, the quantity B0 as defined by B/[(1 - (η)/T)] is a decreasing function of T. On (he basis of experimental result, disagreement between two B values deduced from intra- and inter-chain interactions is pointed out. |
| Databáze: | OpenAIRE |
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