The organic chemistry behind the recycling of poly(bisphenol‐A carbonate) for the preparation of chemical precursors: A review

Abstract

Production and consumption of poly(bisphenol‐A carbonate) resins are seeing a worldwide increase. However, their usage lifetimes are short and their final disposition as landfills pose environmental and health risks, due to the release of toxic bisphenol‐A (BPA). The development of alternative recycling routes is thus becoming subject of increasing interest. In this review, the main recycling processes of poly(bisphenol‐A carbonate) are described and critically compared, with special focus on the chemical mechanisms. While mechanical recycling is possible, the end products are restricted only to polymer blends, whose main mechanical properties decrease with each compounding cycle. In turn, chemical recycling can produce BPA monomer and a variety of by‐products that can be used in different industries, including the polymeric field, as synthesis reagents and precursors. The operation conditions of each method are reviewed, as well as the different results obtained in terms of product yield, composition, selectivity and reaction times. Reaction mechanisms are described in detail and a view on the usability of each end product is offered.

“Functional upcycling” of polymer waste towards the design of new materials

“…Thus, the functional upcycling is further compared with other methods of PC waste recycling based on these reviews. 545,[567][568][569] 2.9.2. Functional upcycling 2.9.2.1.…”

Chemical upcycling of poly(bisphenol A carbonate) to vinylene carbonates through organocatalysis

“…9 In this context, the recycling of BPA-PC is crucial. 10 The chemical recycling of BPA-PC can be performed by pyrolysis; however, it requires harsh reaction conditions and leads to the formation of complex mixtures. 11 So, most other chemical recycling strategies of BPA-PC rely on the electrophilic character of the carbonyl group, thus involving the use of nucleophilic species as depolymerising agents.…”

Straightforward synthesis of aliphatic polydithiocarbonates from commercially available starting materials

“…5 Indeed, several (degradable) polymeric scaffolds decorated with various sulfur-functionalities (e.g., thioethers, thioesters, thiocarbonates, thiourethanes, thioamides, and thioureas among others) are now accessible. 1 Still, compared to the more conventional oxygen-rich polymers (such as aliphatic polycarbonates), 6 the toolbox of polymerizations to furnish sulfur-rich polymers ( particularly, aliphatic polydithiocarbonates in which both of the ethereal oxygen atoms of the carbonate group are replaced by sulfur atoms) remains limited to polycondensation (Scheme 1B) 7 and the ring-opening polymerization (ROP) of cyclic sulfur-containing monomers (Scheme 1C). 8 The mentioned approaches are usually accompanied by unavoidable drawbacks involving the usage of toxic phosgene (or chloroformates) along with the tedious and low yield multiple synthetic steps of the cyclic monomers.…”