However, in the face of increasing public scrutiny, it is imperative research continues to underpin informed decisions to avoid unintended environmental consequences. 8 It is therefore unsurprising recent initiatives have emerged proposing plastics be banned outright, perhaps most notably in packaging applications, and replaced by alternative materials such as paper, glass and aluminium. 7, 8 In 2018, it was reported the Great Pacific Garbage Patch (GPGP) consisted of approximately 1.8 trillion plastic fragments, collectively weighing 79000 tonnes, and continues to grow annually. 6 Whilst prevalent on land, ocean plastics exemplify current levels of plastic pollution within the environment. 1- 5 It has been estimated of the 8.3 billion tonnes of plastic manufactured between 1950 to 2015, 6.3 billion tonnes is now waste, with 79 % accumulating in either landfill or the natural environment. The industries reliance on a depleting fossil feedstock, coupled with a linear model, serves to confound mounting environmental concerns (Figure 1). 1 Whilst their inherent strength and durability is revered during their functional lifetime, such properties render plastics a pervasive environmental pollutant at end-of-life. Plastics have played a crucial role in human development since their commercialisation in the 20th century, revolutionising key sectors such as transport, communications and healthcare. Emerging opportunities and challenges are discussed within the context of industrial feasibility. Finally, the attention shifts to the emergence of new materials with the potential to modernise the plastics economy. Chemical recycling methods for PLA and PET are then discussed, with a particular focus on upcycling and the use of metal-based catalysts. The concept of chemical recycling is first introduced, and associated opportunities/challenges are discussed within the context of the governing depolymerisation thermodynamics. Herein, the aim was to highlight recent developments in the catalytic chemical recycling of two commercial polyesters, namely poly(lactic acid) (PLA) and poly(ethylene terephthalate) (PET). This has stimulated considerable research into renewable alternatives, and more recently, the development of alternative waste management strategies. Whilst plastics have played an instrumental role in human development, growing environmental concerns have led to increasing public scrutiny and demands for outright bans.
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