Blends and clay nanocomposites of cellulose acetate and poly(epichlorohydrin)

The aim of this work was to investigate cellulose acetate/poly(epichlorohydrin) (CA/PEPi) blends and cellulose acetate/poly(epichlorohydrin)/organically modified montmorillonite clay nanocomposites (CA/PEPi/MMTO) prepared by melt processing in a twin-screw extruder. The combination of an elastomer and clay in the cellulose acetate matrix was an attempt made to reach a balance between toughness and strength properties. The blend and nanocomposite structure, morphology and thermal properties were investigated by small angle X-ray scattering, transmission electron microscopy and dynamical mechanical analysis. The results showed immiscibility of the polymer components for all the CA/PEPi blend composition range investigated. In the case of the nanocomposites, the results indicated a significant polymer intercalation in the clay gallery as well as the exfoliation of the silicate layers. Moreover, the organoclay was present in the CA phase, but some of the organoclay migrated to the CA/PEPi interface and tended to surround the PEPi phase. The addition of PEPi elastomer to cellulose acetate showed a significant increase in the blend impact resistance. However the combination of PEPi and MMTO did not in fact produce a good stiffness versus toughness balance. (C) 2011 Elsevier Ltd. All rights reserved.