Liquid chromatography techniques for characterizing poly(Vinyl Alcohol)

Poly(vinyl alcohol) (PVOH) samples may contain several heterogeneities requiring the development of chromatographic techniques for characterization. Size exclusion separations have been carried out using a number of aqueous eluents, incorporating electrolyte, or electrolyte/organic modifier, or surfactant. The most favourable molecular size separation was obtained using 0.25% w/v sodium lauryl sulfate as eluent. Reasonable values for molecular weights of PVOH samples have been determined. Compositional distributions in copolymer systems can be assessed using high‐performance liquid chromatography employing a reversed‐phase separation mechanism. For poly(vinyl alcohol), gradient elution with water/tetrahydrofuran (THF) with a wide pore polystyrene‐based packing produced separations dependent on degree of hydrolysis and sequence length distribution. The elution results were verified with a column packed with non‐porous beads. Partially hydrolysed PVOH samples appeared to have a broad distribution of composition.