Biodegradable films from the lignocellulosic fibers of wheat straw biomass and the effect of calcium ions

Authors: AHMED, SHAFAET - South Dakota State University; JANASWAMY, SRINIVAS - South Dakota State University; Yadav, Madhav

Submitted to: International Journal of Biological Macromolecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2024
Publication Date: 3/3/2024
Citation: Ahmed, S., Janaswamy, S., Yadav, M.P. 2024. Biodegradable films from the lignocellulosic fibers of wheat straw biomass and the effect of calcium ions. International Journal of Biological Macromolecules. https://doi.org/10.1016/j.ijbiomac.2024.130601.
DOI: https://doi.org/10.1016/j.ijbiomac.2024.130601

Interpretive Summary: Packaging materials account for approximately one-third of total plastic use, which results in a significant amount of plastic waste. Some plastics can be hazardous to human health, and its waste results in environmental pollution. Plastic packaging is becoming less popular due to its non-biodegradable nature and disposal problem. The need to find a replacement for plastic with a biodegradable material, prompted us to develop a packaging film from agricultural biomass. Thus, we isolated a cellulose based (cellulosic) material from a low value wheat straw biomass. Then, we dissolved the cellulosic material in water by cross linking it with calcium ions and prepared its film. The packaging film prepared with this cellulosic material has good physical, mechanical and biodegradable properties. Also, the packaging film made with the solution of this cellulosic material containing a higher amount of calcium ions for crosslinking it, is superior to the commercial synthetic films in regard to the strength and biodegradability. Overall, the strong, transparent, and biodegradable films developed from the material obtained from wheat straw biomass look extremely competitive with commercial plastic packaging material. The commercialization of such agricultural waste-based packaging material will benefit US wheat growers and its processors.

Technical Abstract: Many plastics can be hazardous to human health. Most of the plastic waste results in environmental pollution and ecological catastrophe. In the last few decades, biobased polymers from renewable sources have become promising to develop biodegradable packaging films. Among them, lignocellulose from agricultural biomass is inexpensive, renewable, and biodegradable. The present study aims to develop biodegradable films using lignocellulosic residue from wheat straw biomass. The methodology is a green process that solubilizes cellulose chains using zinc ions and crosslinks the cellulose chains through calcium ions with different concentrations (200 – 800 millimolar). The result reveals that the increase of calcium ions significantly decrease the moisture content, water solubility, water vapor permeability, transparency, and elongation of the films. Films containing 800 millimolar of calcium chloride have a tensile strength of about 6.61 megapascal, approximately 2.5 times higher than commercial polyethylene. Around 90 percent of all films biodegrade within a month in soil containing 20 percent moisture content. Overall, lignocellulose residue from wheat straw biomass could be an excellent replacement for synthetic polymer to fabricate strong, transparent, and biodegradable plastic films.