Polymer, Vol.39, No.26, 7127-7129, 1998
In situ X-ray scattering investigations of solutions of cellulose in N-methylmorpholine-N-oxide during shear flow
There are conflicting reports that concentrated solutions of cellulose in N-methylmorpholine-N-oxide (MMNO) exhibit liquid crystal structures as is the case for many cellulose derivatives. We have prepared cellulose/MMNO solutions using two different approaches with compositions in the range 9 to 34% w/w. We have subjected these solutions to in situ X-ray scattering studies during sheer Bow. Such solutions do not develop any significant level of preferred orientation during shear flow. Such zero macroscopic orientation contrasts with the behaviour of related lyotropic liquid crystal polymers based on cellulose derivatives and with other liquid crystal polymer systems, for which, in all cases, a substantial level of preferred orientation develops during shear Bow. We conclude that the range of cellulose/MMNO solutions studied here do not exhibit liquid crystal phases.