Experimental Test of the Twohyphen;Parameter Theory of Dilute Polymer Solutions: Polyhyphen;phyphen;methylstyrene

摘要

In order to test the twohyphen;parameter theory of dilute polymer solutions, lighthyphen;scattering and intrinsichyphen;viscosity measurements were carried out on fractions of polyhyphen;phyphen;methylstyrene in toluene, dichloroethane, cyclohexane, and methyl ethyl ketone at 30deg;C, and in diethyl succinate at temperatures ranging from 16 to 60deg;C. The theta temperature for this polymer in diethyl succinate was found to be 16.4deg;C. With the data for the statisticalhyphen;radius expansion factoragr;Sand the interpenetration functionPSgr;appearing in the second virial coefficient, validity of a theory of these quantities was examined using the two criteria introduced previously: (1) consistency in the values of the excludedhyphen;volume parameterzdetermined fromagr;SandPSgr;, and (2) linearity betweenzand the square root of the molecular weight. It was found that the Yamakawandash;Tanaka theory ofagr;Sand the Kuratandash;Yamakawa theory ofPSgr;were a selfhyphen;consistent pair of intramolecular and intermolecular theories of interaction which satisfied both of the two criteria. The data for the viscosityhyphen;radius expansion factoragr;eegr;indicated no existence of the draining effect, and there was no satisfactory theory ofagr;eegr;. An empirical relation betweenagr;eegr;andzwas obtained, where values ofzwere calculated from observed values ofagr;Susing the Yamakawandash;Tanaka equation. It was found that at smallz, agr;eegr;3thinsp;equals;thinsp;1thinsp;plus;thinsp;C1zthinsp;plus;thinsp;middot;middot;middot;, with1.05thinsp;thinsp;C1thinsp;thinsp;1.55. This is a theoretical problem to be solved. Based on the empirical relation betweenagr;eegr;andz, the equation for the Stockmayerndash;Fixman viscosity plot was revised. Values of the polymerndash;solvent interaction parameterBdetermined from viscosity plots using the revised equations were in good agreement with those from meanhyphen;square radii and also from second virial coefficients.