Professor Guilhem de Hoe

Plastic pollution, low levels of recycling, and ecotoxicological concerns regarding additives and microplastics have driven increased awareness about the unsustainable use of plastics in our modern society as well as their negative impacts on the environment. In this talk, we will cover recent research on plastics additives and ongoing work on understanding structure–property–biodegradation relationships for water soluble polymers (WSPs). Many plastics additives (e.g. antioxidants) are small molecules that are critical to plastic processing and/or performance; however, they can migrate to interfaces and potentially leach into packaged products (during use) or the environment (when plastic waste is mismanaged). Our work addresses this challenge through two generations of innovative polymeric antioxidants that demonstrate comparable—or better—performance than conventional small-molecule counterparts while showing remarkably lowered leaching potential. We demonstrate this using polyethylene terephthalate (PET) as the plastic matrix, incorporating the additives by twin screw extrusion and subjecting the extrudate to a variety of performance tests including oxidative induction time, solvent immersion trials, and colorimetry. Along the way, we show that a seemingly minor change in polymeric additive structure results in a significant benefit to antioxidant efficacy without enhancing leaching potential. In the second portion of the talk we will transition to polymer biodegradation, showing recent respirometric results for common WSPs that highlight just how important it is to contextualize biodegradability claims within a specific “receiving environment.”