V1LSCOMETRIC DETERMINATION OF THE COMPATIBILITY OF DIFFERENT POLYMER PAIRS AND THE HYDRODYNAMIC PROPERTIES OF THEIR DILUTE SOLUTIONS

Abstract

Different polymer pairs comprise polystyrene, poly(ethylene oxtde) and poly(methyl methacrylate) are considered here as mcdels to study the feasibility of the viscosity measurements in estimating the compatibility of aromatic/aliphatic, aliphatic/aliphatic polar/polar and polar/non-polar blends.

A ew equation has been proposed for quick determination of intrinsic viscosity of polymer in solutions in good solvents. The equation has been tested in different polymer-solvent systems. Intrinsic viscosity calculated by this equation is found to be in good agreement with the intrinsic viscosity obtained by graphical extrapolation method according to Huggins' equation.

The intrinsic viscosity of different blends comprise the above mentioned polymers have been measured in benzene at 303.15K as a function of blend composition. In order to predict the compatibility of polymer pairs in solution, the interaction parameter term, So, obtained from the modified Krigbaum and Wall theory, and difference in intrinsic viscosities of the polymer mixtures and weight average intrinsic viscosities of the twa polymer solutions taken separately are used. It is found that the viscosity measurements are suitable to predict polymer-polymer miscibility. The interactions between poly(vinyl pyrrolidone) with chemically simpler substances such as glycine and . sodium sulfate have been studied. It is found that the presence of the micromolecular compound affects to a large extent the phase separation temperature in the polymer solution.