Sustainable, High-Performance, and Biodegradable Plastics Made from Chitin

Abstract

A high-performance biodegradable plastic was made from a chitin KOH/urea solution. The solution was transferred into a hydrogel by cross-linking using epichlorohydrin and ethanol immersion, and a chitin bioplastic was finally prepared by drying in a mold at 40 °C. The solution concentration positively impacts viscosity, crystallinity, and smoothness. A 4% chitin bioplastic exhibits high barrier properties, flame retardancy, high-temperature resistance, mechanical properties (tensile strength up to 107.1 MPa), and soil degradation properties. The chitin bioplastic can be completely degraded by microorganisms in 7 weeks. In addition, biosafety tests suggest that chitin is safe for cells and crops (wheat and mung beans). The chitin bioplastic was further applied to containers, straws, cups, and photoprotection, and it was found that the water resistance and transparency were comparable to those of commercial polypropylene plastics. Due to the excellent performance, safety, and sustainability of the chitin bioplastic, it is expected to become a good substitute for conventional fossil fuel-based plastics.

Uniform Micronano Network Affords All-Chitin Films with Water Resistance, Biodegradability, and High Strength

“…8 With the formation of physical cross-linking bonds (hydrogen bonds) through the dissolution in potassium hydroxide (KOH)/urea solutions, the prepared chitin bioplastic exhibited an excellent tensile strength of ∼107.1 MPa. 9 Moreover, chemical and physical cross-linking were incorporated, resulting in further enhanced strength and toughness. 10 However, with desirable mechanical performance and thermal stability, these chitin nanofiber films still encounter poor water resistance due to the large number of hydroxyl groups on chitin molecular chains.…”

“…The developed mild-proceeded chitin nanofiber films demonstrated a significantly high strength of ∼277 MPa . With the formation of physical cross-linking bonds (hydrogen bonds) through the dissolution in potassium hydroxide (KOH)/urea solutions, the prepared chitin bioplastic exhibited an excellent tensile strength of ∼107.1 MPa . Moreover, chemical and physical cross-linking were incorporated, resulting in further enhanced strength and toughness .…”

Techno-Economic Assessment of Chitin Nanofibrils Isolated from Fungi for a Pilot-Scale Biorefinery

“…In this context, cellulose and chitin, structural polysaccharides widely found in living organisms such as plants, algae, tunicates, crustacean exoskeletons, insects, and fungi, are being exploited as sustainable technological materials. , These materials have proven their suitability for biodegradable packaging, compostable batteries, or to develop materials with negative CO 2 footprint over their fossil-based analogues . Although estimations vary (with mid-range chitin market sizes of around US$ 5000–7720 million by early 2030s), it remains clear that the coming years will witness an increased consumption of chitin-based materials for end-use industries such as healthcare, agrochemicals, pharma or food-sector, to reach estimated compound annual growth rates of 12.1%–13.0% in the next decade. − The hierarchical structure of cellulose and chitin provides an unparalleled opportunity to develop nanofibrillated materials of high axial aspect with upgraded functional properties .…”

Chitinous Bioplastic Enabled by Noncovalent Assembly

“…Polysaccharide (e.g., cellulose, chitin) is the richest renewable polymeric resource in nature, which has been widely used to fabricate functional materials for various applications. − We focused on fabricating chitinous bioplastic. Chitin exists widely in shrimp and crab shells. , The large amount of strong hydrogen bonding interactions impede the mobility of the chitin chains. , Thus, chitin-resourced materials usually show mechanically high fracture strength but brittle features as well as poor processing performance .…”

“…Naturally occurring biopolymer (e.g., DNA, , proteins, lignin, starch, and polysaccharides − ) are the ideal raw materials for producing bioplastic due to their advantages of biodegradability, safety, and sustainability . However, the natural polymer-based materials usually lack good mechanical or processing performance and, thus, are unable to meet practical applications demands .…”