Biopolymer nanocomposites: lessons from structure-property relationships

The urgent need to address sustainability within material science, driven by global environmental concerns over pollution, climate change, and resource scarcity, has led to a growing interest in bio-based materials. This thesis explores the potential of biopolymers as alternatives to non-renewable resources, specifically the ones derived from renewable and residual sources. The biomacromolecules can be harvested from plants, algae, microorganisms, and animal products; or extracted from the process waste of agricultural and urban cycles. In particular, the high stiffness (Young's modulus) exhibited by certain biopolymers, often surpassing that of standard engineering polymers, motivates this investigation. The biopolymers' uncontrolled chemical structure and morphology still inhibit their application in many industries. Inspired by the unique structures, properties, and functions found in biological systems, this research aimed to develop (solid-state) structureproperty relationships for relevant biopolymer systems aiming at predicting final material properties (physicochemical, thermal, mechanical, barrier). The focus on structure-property guidelines is brought about by systematic investigations of the intricate architecture and interactions found in biopolymers and bioinspired nanocomposites. The ultimate goal is to design bio-based materials with superior performance, such as lightweight, high stiffness and strength, and functionality, while at a competitive cost and sustainability.