Styrofoam™ is a petroleum-based material widely used in lightweight, protective packaging systems.1 However, Styrofoam™ is made from non-renewable petroleum resources, is non-biodegradable, it is not recyclable in the vast majority of the existing recycling plants, and can cause chronic, low-level styrene migration into food.2 As a result, to deal with the environmental pollution concerns, crude oil shortages, and possible serious adverse effects on human health, we propose as an alternative to Styrofoam™, biodegradable, naturally foamed soybean oil-based composites containing high amounts of agri-waste.3

Bio-based thermosets were synthesized from epoxidized soybean oil (ESO) cross-linked with PRIPOL 1040, a fatty acid trimer. Thanks to the liquid cross-linker, curing of the composites can be performed at relatively low temperature of 80 °C, in the presence of agri-waste, like carrot residue after juice extraction, spinach stems, or tomato peel, without degrading them. Moreover, moisture present in the agri-waste, evaporates during the curing process creating gas bubbles and providing a natural way of foaming. To give a second life to agri-waste in added-value products, up to 50 % by wt. of vegetable waste was incorporated into the ESO-PRIPOL matrix, which in addition improved tensile and compression strength as well. Most importantly, the composites are biodegradable in marine environments preventing their long-term bioaccumulation in the ecosystem.

1. B. Jethy, S. Paul, S. K. Das, A. Adesina, S. M. Mustakim, Critical review on the evolution, properties, and utilization of plastic wastes for construction applications, Journal of Material Cycles and Waste Management, 2022, 1-17.

2. N. Nismah, U. Suratman, A. Sheila Puspita, K. Mohammad, Effect of Styrofoam Waste Feeds on the Growth, Development and Fecundity of Mealworms (Tenebrio molitor), OnLine Journal of Biological Sciences, 2018, 18 (1).

3. R. Mustapha, A. R. Rahmat, R. Abdul Majid, S. N. H. Mustapha, Vegetable oil-based epoxy resins and their composites with bio-based hardener: a short review. Polymer-Plastics Technology and Materials, 2019, 58 (12), 1311-1326.