LOCAL STRUCTURAL CORRELATIONS IN ANISOTROPIC AQUEOUS-SOLUTIONS OF HYDROXYPROPYL CELLULOSE

Wide-angle X-ray scattering procedures are utilized to study the local structure of isotropic and anisotropic aqueous solutions of hydroxypropyl cellulose (HPC). The X-ray scattering data for a systematic series of solutions with 0-100% w/v HPC are reported and these curves show distinct and significant variations as the concentration of HPC is increased. In particular, a diffuse scattering peak whose position (s approximately 0.34-0.54 angstrom-1) is composition dependent, develops in parallel with the formation of the anisotropic liquid crystal phase. There is no evidence to support the concept of clusters of HPC molecules in the anisotropic phase. The variations in peak positions and the synergistic nature of the scattering suggests that the water is largely associated with each HPC chain.