Hardened wood could replace plastic and steel

Developing natural products to replace synthetic plastics is necessary due to the serious environmental problem of non-biodegradable plastic waste. Cellulose is the most abundant natural material that is from all plants. This paper reports our success in achieving the most stretchable and transparent cellulose-based films through a very green process. The films are highly transparent, with 90% transparency per 100 μm at 550 nm wavelength. The films are very flexible, able to be twisted and folded greatly without breaking. The film can reach an unprecedented maximum of 233% elongation at break. The success in such highly stretchable and transparent films sheds light on the great promise of cellulose for potential applications to replace synthetic plastics, such as transparent and stretchable substrates for flexible and stretchable electronics, transparent and stretchable films and various products. The mechanisms in achieving high transparency, flexibility and stretchability of the cellulose-based films are discussed.