Investigation of the nanostructure, thermal stability, and mechanical properties of polylactic acid/cellulose acetate butyrate/clay nanocomposites

• Physical properties of PLA/CAB blends were first studied.
• One organoclay used in this study acts like compatiblizer in a PLA/CAB blend.
• Both PLA and CAB chains were co-intercalated into the organoclay layers.
• PLA, CAB and organoclay form a copolymer-like structure.
• Mechanical properties of the blend were remarkably increased by the organoclay.

In this study, we investigated the effect of organoclay on the nanostructure, thermal stability, and mechanical properties of polylactic acid (PLA)/cellulose acetate butyrate (CAB) nanocomposites. The incorporation of organically modified montmorillonites into the PLA/CAB blend has improved the thermal stability and mechanical properties. Both the stiffness and toughness of the blends were increased by the organoclay. Two different organoclays, Cloisite®20A (C20A) and Cloisite®30B (C30B), were used. C20A provided a moderate increase of the mechanical properties and thermal stability where the solubility parameter (δ) of the organic modifier in the C20A was somewhat different from the δ of PLA/CAB. On the other hand, C30B provided a substantial increase of the thermal stability and mechanical properties where its δ was the closest to that of PLA/CAB. Two Tgs of PLA and CAB shifted toward each other with the incorporation of the C30B. From several investigations, it was assessed that both PLA and CAB are intercalated into C30B galleries and the combined structure of PLA–C30B–CAB acts like a compatibilizer in the PLA/CAB blend.