The evaluation of polyethylene chain dimensions as a function of concentration in nonadecane

This study reports the findings from a polyethylene chain dimension study a s a function of concentration in concentrated solutions. The concentration range, in terms of volume fraction (Phi). ranged from 0.25 to 1.0. The solv ent was nonadecane (d(40)) while the technique of assay was small angle neu tron scattering at 423 K. Over the range of concentration covered [R-2](0) similar to Phi(0.0) and the second virial coefficient (A(2)) is 0 within th e limits of experimental error. Thus the unperturbed chain dimension is ret ained over a wide concentration range. This demonstrates that the complete screening of excluded volume effects occurs long before the melt-state is r eached; this is in accord with the prediction of the Flory-Edwards mean-fie ld theory approach.