Sustainability of Synthetic Plastics: Considerations in Materials Life-Cycle Management

Abstract

The sustainability of current and future plastic materials is a major focus of basic research, industry, government, and society at large. There is a general recognition of the positive impacts of plastics, especially packaging; however, the negative consequences around end-of-life outcomes and overall materials circularity are issues that must be addressed. In this perspective, we highlight some of the challenges associated with the many uses of plastic components and the diversity of materials needed to satisfy consumer demand, with several examples focused on plastics packaging. We also discuss the opportunities provided by conventional and advanced recycling/upgrading routes to petrochemical and bio-based materials and feedstocks, along with overviews of chemistry-related (experimental, computational, data science, and materials traceability) approaches to the valorization of polymers toward a closed-loop environment.

Sustainable Polymers: Our Evolving Understanding

“…It is worth noting that numerous visions of sustainability are emerging within polymer science. ,− In fact, a recent literature search illuminated many examples, which due to limitations on space and references cannot be fully explored, including CRM strategies, heterogeneous catalysts, homogeneous catalysts, organocatalysts, biocatalysis, diverse methods to synthesize biobased monomers, and increasing use of LCA. This last technique, which attempts to provide the most comprehensive environmental perspective possible, is also challenging to perform.…”

Antioxidant-induced transformations of a metal-acid hydrocracking catalyst in the deconstruction of polyethylene waste

“…contribute to highly varied waste streams that challenge the creation of economic value and reduction of waste accumulation. 1,3,4 For example, within sorted, post-consumer high-density polyethylene (HDPE), numerous colorants, processing aids, macromolecular architectures, fillers, and crystallinities can be present and can introduce significant heterogeneity among recycling inputs (to either mechanical or chemical processes) that limits product value and process scalability. [4][5][6] Valorization routes that consider both the macromolecular and the compositional diversity inherent to all plastics are likely to become widespread strategies that address real, discarded plastics.…”

“…[4][5][6] Valorization routes that consider both the macromolecular and the compositional diversity inherent to all plastics are likely to become widespread strategies that address real, discarded plastics. 3,4,7 Plastics waste contains a vast array of small-molecule additives, 8,9 as many commercial polymers require additives to facilitate processability and improve performance. 6,10,11 For example, HDPE can often contain processing aids that enable molding or extrusion, and certain applications (e.g., outdoor furniture, electronics packaging) necessitate the inclusion of additives, such as ultraviolet (UV) stabilizers or antistatic agents.…”

iPP/PE Multiblock Copolymers for Plastic Blend Recycling Synthesized by Coordinative Chain Transfer Polymerization

“…The two polymers are chemically inert, which means that their depolymerization is difficult, and similar in properties, making their separation problematic. On the other hand, the two polymers are different regarding their chemical structure, so the mutual processing of plastic blends leads to macrophase separation and significant alteration of the original properties. − The addition of block copolymers containing blocks of HDPE and i PP as compatibilizers can mix with both phases and, therefore, avoid macrophase separation and reinstall the original properties of the major component of the blend. − Inspiring studies of (alphabetically) Bates, Coates, Ellison, LaPointe, and co-workers indicate that multiblock copolymers of HDPE and i PP are especially promising regarding HDPE/ i PP recycling. − These multiblock copolymers were synthesized via the living type of polymerization, , where an expensive and sophisticated initiator is required for the synthesis of each copolymer chain. Note that in ref , where copolymers having a PE backbone with i PP side chains were reported, the macromonomer or side chain synthesis was accomplished in a nonliving fashion.…”