Conformational properties of hydroxypropylcellulose—I. Hydrodynamic properties and equilibrium rigidity of its macromolecules

Abstract

Hydrodynamic properties (intrinsic viscosity [η], translational diffusion D and sedimentation S 0) of samples and fractions of hydroxypropylcellulose (HPC) have been investigated in a number of solvents. The relationships between [η], D and S 0 and the degree of polymerization of HPC in dimethylacetamide and tetrachloroethane were established. The equilibrium rigidity of HPC molecules was determined from the data on translational diffusion and viscometry; the length of the statistical segment is (210−240) × 10 −8 cm. This evaluation of rigidity is in agreement with the rigidity parameters of other cellulose derivatives. It may be assumed that, just as for most mesogenic polymers, it is the high rigidity of the molecules that determines the possibility of mesophase formation in HPC solutions and melts.