Simultaneous dual-mechanism separation of a semicrystalline polymer blend on large-pore silica by temperature-programmed packed capillary liquid chromatography

An extruded polymer blend product, containing high molecular weight semicry stalline polypropylene and polyphenylene ether grafted to maleic anhydride, has been resolved by the use of temperature-programmed packed capillary li quid chromatography with evaporative laser light scattering detection. A la rge-pore neat silica stationary phase material provided a dual-mechanism se paration simultaneously on the same column, eluting polypropylene according to a size exclusion mechanism and polyphenylene ether according to normal phase interaction. Packed capillary columns of 0.32 mm ID and 100-cm length with rapid temperature programming from 110 to 170 degreesC were required in order to resolve the materials, offering efficient gradient elution of a nalytes that are not suitable for traditional solvent gradient elution.