Carboxymethyl cellulose/montmorillonite bionanocomposite films incorporated with polyhedral oligomeric silsesquioxane

In this work, carboxymethyl cellulose (CMC)/montmorillonite (MMT) bio-nanocomposite films were prepared by intercalating MMT with polyhedral oligomeric silsesquioxane (POSS) to promote the interfacial interactions between CMC and MMT and overcome limitations of CMC such as its moisture barrier property, thermal, and mechanical properties with maintaining its transparency, biocompatibility, and film-forming ability, etc. POSS combined with ammonium and imidazolium groups (POSS-ammonium and POSS-imidazolium) were prepared by the hydrolysis of organic silane compounds and intercalated into MMT via an ion-exchange reaction. MMT intercalated with POSS-ammonium and POSS-imidazolium are designated as MOAP and MOIP, respectively. MMT modified with POSS-imidazolium (MOIP) was adequately dispersed in the polymer matrix owing to the increased gap between the MMT layers and electrostatic interaction between POSS at the MMT edge and carboxylate moieties on CMC chain. The good compatibility and interaction between MOIP and CMC as well as higher thermal stability of heterocyclic compound in POSS-imidazolium endowed the bionanocomposite films with excellent mechanical properties and thermal stability. Furthermore, UV-barrier, moisture barrier, antibacterial, and antioxidant properties of the CMC bionanocomposite films were effectively improved with the introduction of MOIP.