Enriching Poly(lactic acid) Properties: Impact of Chitosan Nanoparticles and Jojoba Oil on Physico-chemical Characteristics and Isothermal Crystallization Behavior

Abstract

Abstract Poly(lactic acid), PLA, loaded with chitosan nanoparticles, CsNP, (3.0%, w/w) and jojoba oil, JO, (3.0%, w/w), as a plasticizer, were prepared by twin screw extrusion. The manufactured PLA/CsNP, PLA/JO and PLA/CsNP/JO compounds were characterized by differential scanning calorimetry (DSC), thermogravemetric analysis (TG), tensile testing, Izod impact test and wide angle X-ray diffraction (WAXD). The PLA/CsNP, PLA/JO and PLA/CsNP/JO compounds exhibited improved elongation and impact strength compared with neat PLA. The presence of JO slightly improved the thermal stability of PLA, while CsNP decreased the thermal stability of the PLA. The incorporation of CNPs and JO accelerated the cold crystallization rate of PLA, which is related to a nucleation effect of the CsNP and increase of the chain mobility as a plasticization effect of the JO. No modification in crystalline structure of PLA was observed as a result of the presence of the CsNP and the JO. Avrami equation was employed to describe the cold and melt isothermal crystallization process of neat PLA and PLA/CNP composite with and without JO. The combination additives of CsNP and JO accelerated the crystallization rate in a less extent than CsNP or JO alone.