화학공학소재연구정보센터
Macromolecules, Vol.30, No.26, 8360-8364, 1997
Study of thermoreversible aggregates from chemically-modified PVCs
We report on a light scattering study performed on suspensions of aggregates of PVC and chemically-modified PVCs in diethyloxalate (DEO). The maximum in the scattering function reported by Mutin and Guenet is again observed. Its position, q(m) depends upon the degree of chemical modification at constant polymer concentration: the larger the degree of modification, the lower the value of q(m). The radius of gyration and the weight-averaged molecular weight of the aggregates are determined as a function of the preparation concentration from highly diluted suspensions. The radius of gyration is found to remain virtually unchanged when augmenting the degree of modification while a near 2-fold increase of the weight-averaged molecular weight is observed, the latter being consistent with the variation of q(m). All these results point toward a cross-sectional growth of the fibrillar aggregates with chemical modification while the longitudinal fractal dimension does not vary significantly. Viscometry measurements provide further support to these conclusions.