From molecular interactions to functional performance: A systematic review of structure–property–application relationships in bio-derived bioplastic films

Bio-derived bioplastic films have attracted increasing attention as potential alternatives to conventional petroleum-based plastics, particularly for sustainable packaging applications. However, their functional performance varies considerably across polymer systems, formulations, processing conditions, and testing environments, making it difficult to establish transferable material-design principles. This systematic review critically synthesizes structure–property–application relationships in bio-derived bioplastic films, emphasizing how molecular interactions, interfacial compatibility, morphology, crystallinity, and network organization influence mechanical, barrier, thermal, optical, active, and degradation properties. The synthesis identifies recurring relationships between hydrogen bonding, crosslinking, filler dispersion, interfacial adhesion, and macroscopic film performance. Improved structural cohesion and interfacial compatibility are frequently associated with enhanced mechanical strength and barrier properties, although these benefits may be accompanied by reduced flexibility, altered permeability, or increased sensitivity to environmental conditions. The effectiveness of reinforcement, plasticization, and functional modification is therefore formulation-dependent, highlighting the importance of balancing competing properties rather than maximizing individual performance indicators. Application-oriented evidence further indicates that promising laboratory-scale properties do not necessarily translate into practical suitability, particularly where food-contact safety, long-term stability, processing scalability, and realistic end-of-life performance remain insufficiently demonstrated. By integrating evidence across diverse biopolymer families and hybrid systems, this review proposes a multiscale structure–property–application framework to support application-specific material selection and future experimental design. The findings emphasize the need for standardized characterization, stronger mechanistic validation, and application-relevant testing to advance bio-derived bioplastic films toward reliable and sustainable implementation.