Polymer conformation and viscometric behaviour - 1. Conformational transition in poly (benzyl methacrylate) in dilute solutions

The viscometric and refractometric behaviour of poly (benzyl methacrylate) (PBM) in isobutyl methyl ketone (IMK) as a function of the temperature was studied. The viscometric relations in IMK and toluene by membrane osmometry and GPC at 25°C were established. The viscometric results show discontinuities in the intrinsic viscosity [η] in IMK and sharp changes in the conformational and thermodynamic parameters K_θ and B. The variation on the unperturbed dimensions of the polymer chain was attributed to a conformational transition. The influence of the side groups was analyzed. The conformational behaviour of this polymer was compared with the saturated corresponding poly (cyclohexyl methyl methacrylate).