DETERMINATION OF THE MAXIMUM SWELLABILITY OF POLYMER BY MONOMER USING CONDUCTIVITY MEASUREMENTS

The maximum swellability of the polymer phase by monomer is an important parameter in emulsion polymerization. This parameter can be determined either by traditional monomer partitioning experiments or by conductivity measurements. The use of conductivity measurements to determine swellability values is new and rather simple. Compared to conventional monomer partitioning experiments it is less laborious and, in those cases where the monomer-saturated polymer phase has a higher density than the saturated aqueous phase, more accurate results can be obtained, For styrene (Sty) and methyl methacrylate (MMA), the maximum swellabilities were determined in a series of Sty-MMA copolymers by traditional monomer partitioning experiments and by conductivity measurements. From the good agreement it could be concluded that conductivity measurements indeed are a useful method of determining maximum swellability values. (C) 1995 Academic Press, Inc.