SOLUTION PROPERTIES OF A HYDROPHOBICALLY ASSOCIATING CELLULOSIC POLYMER - ELECTRON-SPIN-RESONANCE SPECTROSCOPY

Electron spin resonance spectroscopy has been used to investigate the solution properties of a hydrophobically associating cellulosic polymer. Nitroxide spin labels covalently attached to the cellulosic backbone have given information with regard to the segmental motion of the polymer chains, whereas nitroxide spin probes have demonstrated the formation of regions of hydrophobicity above a critical polymer concentration. The data is consistent with the formation of an extensive three-dimensional network in which the hydrophilic cellulosic backbones are effectively cross-linked by the intermolecular association of neighbouring hydrophobic side chains. The work has been extended to study the interaction of the polymer with sodium dodecyl sulphate surfactant and the electron spin resonance data has been used to elucidate the mechanism of interaction, and to explain the unusual rheological behaviour.