Potential substitutes for plastics derived from fossil fuels may be concealed in trash cans and kitchen cabinets. Foods including coffee grounds, tomato peels, and gluten are being investigated by researchers as potential starting materials for polymer-based technologies.
This table is made from a material containing an unexpected foodstuff: coffee grounds. Image Credit: ACS Omega 2024
Three papers recently published in ACS journals report on new products derived from these sustainable resources.
Coffee Grounds to Coffee Tables
Researchers combined leftover grinds with biobased polylactic acid to develop a material that can be printed in vast quantities using large-format 3D printing. The researchers used the plastic composite to 3D print a life-sized side table as a proof of concept, according to ACS Omega.
Tomato Peels to High-Tech Bioplastic
An article in the journal ACS Sustainable Chemistry & Engineering describes a polyester plastic derived from tomatoes that retain its prior forms. The yellow substance was heated to a high temperature and used to distort a ring.
After being submerged in a warm water bath at 140 º F, the ring reverted to its former shape. This proof-of-concept demonstrates how abundant food and agricultural waste can be used to create biobased polyesters.
Gluten to a Compostable Composite
A group of researchers combined carbon fibers with wheat gluten, occasionally added to bread dough to give it more chewiness, to develop the biobased composite.
The study, which was published in the journal ACS Omega, shows that although the gluten-based material was as strong as plastics derived from fossil fuels, it degraded in soil in 30 days and had no effect on the germination or growth of grass seeds. According to the team, the concept might make it possible to mold future products into any size or shape.
Journal References:
Paramatti, M., et.al., (2024). PLA Feedstock Filled with Spent Coffee Grounds for New Product Applications with Large-Format Material Extrusion Additive Manufacturing. ACS Omega. doi.org/10.1021/acsomega.3c05669
Marc, M., et al. (2024). From Tomato Pomaces Biorefinery to Biobased Shape-Memory Semicrystalline Polyester Networks. ACS Sustainable Chemistry & Engineering. doi.org/10.1021/acssuschemeng.3c05713.
Capezza, A. J., et al. (2023). Biodegradable Fiber-Reinforced Gluten Biocomposites for Replacement of Fossil-Based Plastics. ACS Omega. doi.org/10.1021/acsomega.3c07711.