Lyotropic liquid crystalline cellulose derivatives in blends

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Cellulose and some of its derivatives can form liquid crystalline solutions in a variety of solvents. In this context, the present work investigates a series of blends obtained from 0/100, 25/75, 50/50, 75/25, 100/0 wt./wt cellulose acetate phthalate (CAP) / hydroxypropyl cellulose (HPC) in N,N- dimethylacetamide (DMAc). The flow behaviour of their mixed solutions was investigated by means of shear viscometry and oscillatory shear tests. The effect of composition, temperature and shear rate on the rheological functions reflects the orientation or mobility of the chain segments in the shear field. These studies contribute to the knowledge of specific interactions - which can modify liquid crystalline properties of cellulose derivatives, and to diversify their applications in electronic domain.