Lyotropic liquid crystalline cellulose derivatives in blends and molecular composites

Cellulose tricarbanilate (CTC)/methylacrylate (MA) solutions were prepared and the methylacrylate polymerised to produce a series of molecular composites. The solutions were studied using polarised microscopy. The mechanical properties and morphology of the composites were investigated using dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM). Although the SEM micrographs for composites with <45 wt % CTC revealed an apparent one-phase system, DMTA measurements indicated the existence of a double T-g. The 45 wt % CTC composites however showed a broad relaxation process with a third T-g corresponding to the glass transition of the CTC itself. This result which is indicative of phase separation, is consistent with the SEM micrographs showing distinctive layered structures within the film.