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Polyvinyl alcohol (often abbreviated as PVOH) is a water-soluble synthetic material used as an emulsifier and adhesive. PVOH can be modified by reaction of pendant –OH groups with various reagents to form new polymers with novel surfactant properties. Gel permeation chromatography (GPC) is a well-known technique for assessing the molecular weight distribution of polymers, a property that influences many of their physical characteristics. GPC viscometry employing a viscometer in combination with a differential refractive index detector may be used to determine accurate molecular weights for polymers based on the universal calibration approach, useful for materials for which narrow standards are not available. GPC viscometry can also be used to investigate the solution behavior of modified polymers, a useful tool in the analysis of surfactant materials. This application note describes the analysis of two PVOH materials by GPC viscometry – one pure PVOH, and one that had been modified by reaction with imidazole. This second material was insoluble in water so for comparison both materials were analyzed in a polar organic solvent, dimethyl sulfoxide.
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