CHARACTERIZATION OF POLYDISPERSE SOLUTIONS OF BRANCHED POLY(METHYL METHACRYLATE) USING SIZE-EXCLUSION CHROMATOGRAPHY WITH ONLINE MULTIANGLELIGHT-SCATTERING AND VISCOSITY DETECTION

We have studied the mass distribution (N(M)) of branched poly(methyl m ethacrylate) (PMMA) formed by radical copolymerization of methyl metha crylate and ethylene glycol dimethacrylate by size exclusion chromatog raphy (SEC). We show how the static structure factor of monodisperse b ranched PMMA can be obtained using a new type of on-line multiangle li ght scattering detector. We compare the monodisperse static structure factor with that of the polydisperse solutions and show that the polyd isperse static structure factor can be derived from the monodisperse f unction using N(M) obtained from SEC. Both the static structure factor and the mass distribution are found to be consistent with predictions from percolation theory. Using an on-line viscometer we have determin ed the molar mass dependence of the intrinsic viscosity.