Development of lignin-based biodegradable polymer from Agro-waste

Biosourced and biodegradable polymers have garnered substantial attention for their role as sustainable and environmentally friendly alternatives to traditional synthetic polymers, finding diverse applications across various fields. The escalating global demand for food production and a surge in agricultural activities have resulted in a significant increase in agro-waste generation. In India, an agro-waste annual output ranging between 85-100 million tonnes is observed, with wheat straws contributing substantially to approximately one-third of the total agro residue [6]. Addressing the challenge of agro-waste utilisation, we present an innovative methodology for converting wheat straw into a Biodegradable polymer (acetyl ferulic acid polymer). The process involves the extraction of lignin through an acid-base neutralisation reaction, with the qualitative confirmation of lignin presence achieved through Safranin dye testing. The extracted lignin undergoes oxidation via the Nitrobenzene Oxidation (NBO) method, facilitating the conversion into Vanillin through sidechain oxidation of the complex lignin structure. The subsequent acetylation of Vanillin is carried out to obtain acetyl ferulic acid, which is then polymerised utilising zinc acetate as a catalyst. Glycerol is employed as a plasticiser, and the biodegradability of the resulting polymer is assessed within a controlled ambient decomposition environment in the laboratory. Decomposition data is subjected to modelling using Wolfram Mathematica, yielding the decomposition time. Our findings assert that the developed biodegradable polymer requires approximately 105 days to decompose, achieving a degradation rate of approximately 99.98%. This newly synthesised biopolymer is posited to exhibit compatibility with existing biodegradable polymers, thus contributing to the advancement of sustainable polymer materials.