3D Printable Sustainable Composites with Thermally Tunable Properties Entirely from Corn-Based Products

Renewable and biodegradable composites derived from natural resources are receiving increasing attention for sustainable manufacturing. Developing eco-friendly and robust biocomposites can alleviate health and environmental concerns associated with the reliance on petroleum-based plastics. Here, we develop a sustainable composite, made entirely from corn products and waste, and investigate a thermally strengthened mechanism for tunable mechanical properties. A two-step chemical process is used to extract cellulose fibers from corn husks and distribute them in corn starch-derived matrices to develop 3D printable biocompo-sites. Ink preparation is tailored with water content and thermal treatment to achieve desired rheological properties for direct ink writing. By harnessing a thermally controlled hydrogen bonding mechanism between matrix and fibers, the printed samples have tunable mechanical properties up to 3.3 fold. The chemical interactions among amylopectin molecules also result in different porous microstructures, leading to lightweight composites. The composites purely from biomass and waste are a new class of additively manufacturable sustainable materials that can be used as alternatives to petroleum-based plastics in engineering applications and in the fields of medicine and the food industry.

Automated summary

Renewable and biodegradable composites made from corn products and waste have been developed as an alternative to petroleum-based plastics. By extracting cellulose fibers from corn husks and distributing them in corn starch-derived matrices, 3D printable biocomposites with tunable mechanical properties have been achieved. The thermally controlled hydrogen bonding mechanism between matrix and fibers allows for the adjustment of mechanical properties, and the chemical interactions among amylopectin molecules result in lightweight composites with different porous microstructures.