Entanglement Effects in Concentrated Polymer Solutions from Viscosity Measurements

Abstract

The viscosity—molecular weight relation for the system polymethyl methacrylate—diethyl phthalate has been measured.Polymer concentrations of 0.10, 0.15, 0.20, and 0.25 g/cc have been used. No variation in entanglement molecular weight Me in the range 30°—80°C was found. Theoretical predictions for the dependence of Me on concentration have been confirmed. After correcting the data for variation in Tg with molecular weight, the dependence of viscosity on molecular weight predicted by theory is confirmed. Possible reasons are given for the discrepancy between the present conclusions concerning Me and those arrived at from considerations of dynamic data on the same system.