A Soy Protein-Based Composite Film with a Hierarchical Structure Inspired by Nacre

Abstract

Soy protein-based composite film is a potential replacement for petroleum-based film with multipurpose applications and cleaner production. It is difficult to improve both the tensile strength and toughness of a protein-based film without sacrificing its elongation. In this study, inspired by the hierarchical structure of nacre, a facile yet delicate strategy was developed to fabricate a novel bio-based film with excellent toughness and high strength. Triglycidylamine (TGA) crosslinked soy protein (SPI) as hard phase and thermoplastic polyurethane elastomer (TPU) as soft phase comprise an alternative lay-up hierarchical structure. The interface of these two phases is enhanced using triglycidylamine (TGA) surface-modified TPU (MTPU). The tensile strength of SPI/MTPU/TGA films increases by 392% to 7.78 MPa and their toughness increases by 391% to 8.50 MJ/m 3 compared to soy protein/glycerol film. The proposed hierarchical structure can also be extended to other high-performance materials and polymers.

Recent Progress in Robust Regenerated Soy Protein Film

“…Given that plasticizers with small molecule tend to migrate to the surface of the membrane, causing contamination of SP film and reduction in mechanical properties, the use of longchain macromolecular plasticizers and hyperbranched plasticizers for plasticization modification of SP film is an effective strategy. [67][68][69] As a result of the hydrogen bonding interaction between long-chain PVA and SP, a sacrificial hydrogen bond network is formed, increasing the toughness of the film to 29.5 MJ m −3 . [70] Polyamide-polyamine compounds (PPC), which are obtained by reacting adipic acid with diethylenetriamine, can form strong intermolecular interactions such as hydrogen bonds or ionic bonds with the substrate, significantly improving the flexibility and ductility of materials.…”