In this study, green composite films based on cellulose nanocrystal/chitosan (CNC/CS) were fabricated by solution casting. FTIR, XRD, SEM, and TEM characterizations were conducted to determine the structure and morphology of the prepared films. The addition of only 4 wt.% CNC in the CS film improved the tensile strength and Young’s modulus by up to 39% and 78%, respectively. Depending on CNC content, the moisture absorption decreased by 34.1–24.2% and the water solubility decreased by 35.7–26.5% for the composite films compared with neat CS film. The water vapor permeation decreased from 3.83 × 10⁻¹¹ to 2.41 × 10⁻¹¹ gm⁻¹ s⁻¹Pa⁻¹ in the CS-based films loaded with (0–8 wt.%) CNC. The water and UV barrier properties of the composite films showed better performance than those of neat CS film. Results suggested that CNC/CS nanocomposite films can be used as a sustainable packaging material in the food industry.

Eco-friendly cellulose nanocrystal/silver/alginate (CNC/Ag/Alg) bionanocomposite films were successfully prepared by blending of CNC with Ag/Alg solution. The CNC was fabricated from cellulose microcrystal (CMC) by acid hydrolysis method. The Ag nanoparticles (AgNPs) were generated by using Alg as a reducing agent through hydrothermal process. AgNPs-included composite films showed characteristic plasmonic effect of the AgNPs with the maximum absorption at 491 nm and they also showed high ultraviolet (UV) barrier properties. The CNC/Ag/Alg composite films were analyzed by using scanning electron microscopy, transmission electron microscopy, optical microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction technique. Depending on the type of nanofillers, tensile strength of the composite films increased by 39–57% and water vapor permeation decreased by 17–36% compared with those of the neat Alg films. The Ag/Alg and CNC/Ag/Alg films showed brown color as detected from the increase of both ‘b’ and ‘a’ parameters by colorimeter. The UV and water barrier properties of Alg based composite films were found higher than the Alg films. The obtained results suggested that the prepared composite films can be used in food packaging applications.

A novel, biologically friendly polymer with shape memory and self-healing properties based on poly(propylene carbonate) (PPC)/microfibrillated cellulose (MFC) was prepared.

In this work, we report a facile strategy to prepare super-tough and heat-resistant poly(L-lactide) (PLLA) blends by constructing stereocomplex (sc) crystallites with dual interfacial adhesion enhancer/matrix crystallization accelerator functionality at the interface of the blends of PLLA/ethylene copolymer. To exploit the dual functionality, poly(D-lactide) grafted ethylene–acrylic ester copolymer (EMA-g-PDLA) capable of collaborating with the PLLA matrix to form the sc crystallites was first prepared via melt coupling reaction between end groups (carboxyl and hydroxyl) of PDLA and excess epoxy group of EMA–glycidyl methacrylate copolymer (EMA–GMA). During subsequent melt-blending of PLLA with the prepared EMA-g-PDLA, sc crystallites are formed at the interface. The results show that, compared with PLLA/EMA–GMA and PLLA/EMA-g-PLLA blends, injection molded PLLA/EMA-g-PDLA blends have much higher impact toughness and heat resistance because the interface-localized sc crystallites can induce substantial enhancement in both interfacial adhesion and matrix crystallinity. More interestingly, by modulating the amount of sc crystallites at the interface of the blends, optimum impact toughness can be achieved due to the optimization of interfacial strength and matrix crystallinity. This work provides a new concept for the fabrication of high-performance PLLA blends by tailoring matrix and interface properties with the aid of sc crystallites.