Construction of thermoplastic cellulose esters matrix composites with enhanced flame retardancy and mechanical properties by embedding hydrophobic magnesium hydroxide

Biomass-based composites with renewability and biodegradability have attracted extensive researches, but their applications are hindered by poor mechanical properties and flame retardancy. Cellulose ester matrix composites (CEMC), a kind of biomass-based composites, were prepared with inorganic crystals as flame retardant and reinforcement. Cellulose acetate oleate (CAO) prepared by mechanical activation-assisted solid-phase reaction was used as thermoplastic matrix. Hydrophobic oleate-magnesium hydroxide (O-MH), which was surface-modified with oleic acid, was embedded into CAO to prepare O-MH/CAO composites by hot pressing. The introduction of oleoyl contributed to favorable thermoplasticity of cellulose ester, resulting in enhanced thermal stability and mechanical properties of CEMC. The uniform dispersion of O-MH in the CAO matrix via metal-organic coordination increased the mechanical properties and flame retardancy of O-MH/CAO composites, ascribing to the toughening effect and combustion inhibition effect induced by O-MH. This study provides a feasible technology for fabricating the CEMC with outstanding thermal stability and mechanical properties.