Production of Biodegradable Plastic Composites Using Agricultural Residual Biomass

<b>Global plastic pollution is a major environmental problem, with millions of tons of plastic waste accumulating in the oceans and landfills every year [2]. It becomes crucial to develop biodegradable alternative materials that generate less greenhouse gas emissions, can be broken down by microorganisms in the environment, and improve soil health and fertility when composted. Many currently available bioplastics, such as polylactic acid (PLA), fail to biodegrade effectively unless treated under conditions found in commercial composting facilities – high temperatures and forced air [4]. Other more biodegradable polymers are typically challenged by either high manufacturing costs or poor strength and barrier properties [3]. An innovative approach to imparting biodegradability to a polymer while achieving excellent mechanical characteristics consists of introducing fibrous structures into polymer matrices. This method not only endows the composite with good mechanical properties but also provides a vehicle for water and biodegrading enzymes to slowly penetrate the composite structure leading to complete biodegradation [7]. Recent research revealed that the incorporation of nanocellulose into polymer matrices can improve the composite performance both in terms of strength and biodegradability [1, 5, 7]. The present work reports the production of lignocellulosic nanomaterials from inexpensive wheat straw feedstock and alkaline peroxide pulping followed by mild peracetic acid treatment at pilot scale [6, 7]. The resulting cellulose nanofibrils have been extensively characterized and applied to prepare thin, flexible, and translucent composite films with low poly(vinyl) alcohol contents (i.e. below 40 wt.%) using a simple solvent casting method. The mechanical, optical, and barrier properties of as-prepared composites have been thoroughly examined. This novel bioplastic has the potential to replace petroleum-derived plastics across a broad range of industries such as aquaculture, agriculture, food packaging, and more; promising applications include ground covers, drip lines, gooey duck tubes, aqua nets, and paperboard lining or film covering for food packaging [2, 3, 8]. Furthermore, this work provides an analysis of the techno-economic performance of the system accounting for optimization of operational efficiency, cost-effectiveness, and sustainability factors. The findings contribute valuable insights into resource allocation and investment strategies in sustainable bioproduct systems. </b><br/><br/><b>[1] Abraham, E., et al., X-ray diffraction and biodegradation analysis of green composites of natural rubber/nanocellulose. Polymer Degradation and Stability, 2012. 97(11): p. 2378-2387.</b><br/><b>[2] Huang, Y., et al., Agricultural plastic mulching as a source of microplastics in the terrestrial environment. Environmental Pollution, 2020. 260: p. 114096.</b><br/><b>[3] Kjeldsen, A., et al., A Review of Standards for Biodegradable Plastics. Industrial Biotechnology Innovation Centre, 2018. </b><br/><b>[4] Muniyasamy, S., et al., Mineralization of Poly(lactic acid) (PLA), Poly(3-hydroxybutyrate-co-valerate) (PHBV) and PLA/PHBV Blend in Compost and Soil Environments. Journal of renewable materials, 2016. 4(2): p. 133-145.</b><br/><b>[5] “Nanofibrillated Cellulose (Cellulose Nanofibril)”. accessed 17 November 2021.</b><br/><b>[6] Pascoli, D., et al., A Robust Process to Produce Lignocellulosic Nanofibers from Corn Stover, Reed Canary Grass, and Industrial Hemp. Polymers, 2023. 15(4): p. 937. </b><br/><b>[7] Pascoli, D., et al., Lignocellulosic nanomaterials production from wheat straw via peracetic acid pretreatment and their application in plastic composites. Carbohydrate Polymers, 2022. 295: p. 119857. </b><br/><b>[8] Pearce, C.M., et al., Juvenile geoduck (Panopea generosa) predator protection with tubes: Assessing effects of tube diameter, length, and mesh size on growth and survivorship. Aquaculture Reports, 2019. 14: p. 100190. </b>