Compositional fractionation of poly(methyl methacrylate)-graft-polydimethylsiloxane by reversed-phase high-performance liquid chromatography

The results are reported of the compositional fractionation of poly(methyl methacrylate)-graft-polydimethylsiloxane (PMMA-graft-PDMS) by high-performance liquid chromatography (h.p.l.c.) of reversed-phase adsorption mode. Graft copolymers with different compositions were prepared by the radical copolymerization of PDMS macromonomer with MMA, using azobisisobutyronitrile as the initiator in benzene at 60°C. The gradient h.p.l.c. measurements were made using a prepacked column of octyl-modified silica gel, with tetrahydrofuran and acetonitrile as eluents. Detection was performed by an evaporative light-scattering detector. The PMMA-graft-PDMS samples were eluted from the components of higher PMMS contents to those of lower PMMA contents, according to reversed-phase adsorption. The present graft copolymers were separated according to their chemical compositions.