CHARACTERIZATION OF CHEMICAL HETEROGENEITY OF GRAFT COPOLYMER BY CONVENTIONAL SEC

Poly(methyl methacrylate) grafted with poly(dimethyl-siloxane) was investigated by size exclusion chromatography coupled with refractometric and low-angle laser light scattering detectors. Using successively toluene and tetrahydrofuran as eluents, a variation in chemical composition and molecular weight of individual copolymer blocks as a function of hydrodynamic volume were measured. Chemical composition distribution and heterogeneity parameters of the copolymerization product were approximated and compared with the results obtained by supercritical fluid extraction fractionation and by fractionation in demixing solvents.