Review on cellulose nanocrystal-reinforced polymer nanocomposites: Processing, properties, and rheology

The use of nanocomposites is regarded as a promising strategy to significantly improve the overall performance of polymeric materials using a minimal amount of additives. Recently, environmental pollution issues caused by discarded plastic waste have encouraged manufacturers and researchers to replace petroleum-based non-degradable plastics with biomass-derived degradable plastics. Recent research interest in polymeric nanocomposites has resulted in the development of biodegradable nanocomposites using bio-derived nanofillers. Cellulose nanocrystals (CNCs) are one of the most fascinating and widely investigated reinforcing fillers derived from biomass sources such as plants. Compared with conventional inorganic fillers, including carbon nanotubes and metal nanoparticles, CNCs are the most abundant renewable materials on Earth. They do not result in biodegradability deterioration when incorporated into biodegradable polymers. In addition, CNCs exhibit superior dispersibility and chemical affinity to polymeric matrices, resulting in better reinforcing efficiency. Accordingly, considerable effort has been devoted to achieve the desired processability, rheological behavior, and final performances of CNC-loaded nanocomposites. This review aims to provide an overview of the effects of CNCs on the processing, physical properties, and rheology of various types of polymer nanocomposites.