Biocomposites and bionanocomposites from poly(lactide) and cellulosic materials – a review

Abstract

Global environmental concerns have recently accelerated interest in the usage of biodegradable polymers to replace petroleum-based conventional plastics. Lactic acid-based polymers are some of the most promising and widely studied biobased materials, which are suitable for packaging and biomedical applications. This is mainly due to their appealing characteristics such as relatively good mechanical properties, biocompatibility, and multiple end-of-life options such as recyclability and biodegradability in industrial composting conditions. However, the use of lactic acid-based polymers in advanced applications is constrained by their inherent brittleness, poor melt strength, and relatively high cost. These disadvantages can be remedied by reinforcement with cellulose nanomaterials which can enhance their mechanical properties while maintaining their biodegradability. This review provides an overview of recent studies on the development of biodegradable lactic acid-based polymer composites and nanocomposites reinforced with cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs) and microcrystalline cellulose (MCC). The different processing methods and chemical modification techniques utilised on modification and functionalisation of cellulosic nanomaterials for improving the properties of lactic acid-based polymer nanocomposites are also discussed.