Chemical Degradation of Poly(bisphenol A carbonate) Waste Materials: A Review

Abstract

Plastics are indispensable and integral part of our daily life. Each year, we generate tonnes of plastics waste. Poly(bisphenol A carbonate) has created a space for itself in the plastic industry due to its high performance properties. The high rate of production created a major challenge in its management after use or becoming as waste. In this brief review, we have described the chemical degradation of poly(bisphenol A carbonate) and the use of catalyst and reagents. Some of the most utilized chemical degradation methods like alcoholysis, hydrolysis and aminolysis have been explained in detail. The chemical reactions involved in the degradation process have also been discussed.

100th Anniversary of Macromolecular Science Viewpoint: Toward Catalytic Chemical Recycling of Waste (and Future) Plastics

“…ILs − and organic bases − have also been well studied for depolymerizations of bisphenol A (BPA)-PC waste . The monomers obtained from alcoholysis often yield BPA and small carbonates that can be polymerized directly back to PC, however, carbon dioxide can be eliminated by hydrolysis, precluding the return to an original material.…”

Divergent methods for polyester and polycarbonate depolymerization with a cobalt catalyst

“…Since solvolysis is not commonly done with isopropanol, additional studies will be needed to compare to other methods that prioritize hydrolysis, methanolysis, and glycolysis. 11,18,[22][23][24][65][66][67][68][69][70][71] This shows diversity of the catalyst, as solvolysis is primarily studied for PET and PBPAC.…”

Catalyst-Free Approach for the Degradation of Bio- and CO2-Sourced Polycarbonates: A Step toward a Circular Plastic Economy

“…Following a century of innovation, commodity polymers have reshaped our modern lifestyle and quality by entering into numerous everyday consumer goods. However, their long-term accumulation in nature and oceans coupled with the lack of viable end-of-life recycling scenariogenerally limited to single usehas turned their magic into an environmental disaster. − This prompted the scientists to develop new approaches to recycle or upcycle the plastics. − While polyolefins or vinyl-type polymers are difficult to depolymerize by chemical pathways due to strong C–C bonds constituting their main-chain backbone, step-growth polymers with in-chain C–O or C–N linkages (such as polyesters, polycarbonates, polyurethanes) offer multiple chemical depolymerization opportunities. , In this context, solvolysis is now privileged by being enabled to regenerate the initial monomers (for close-loop recycling) or to develop new value-added chemicals (for open-loop recycling). − This is typically exemplified with a representative bisphenol A polycarbonate that was extensively depolymerized into the native bisphenol A via hydrolysis, or into mixtures of bisphenol A and carbonylated products ((a)­cyclic carbonates, oxazolidinones, or ureas) by alcoholysis or aminolysis (Scheme A). − However, most of these depolymerization pathways are generally slow and/or necessitate high temperatures (> 90 °C), and use thermally stable (1,5,7-triazabicyclo[4.4.0]­dec-5-ene and methanesulfonic acid (TBD:MSA) salts or ionic liquids) − or sophisticated (ZnO nanoparticles/ n Bu 4 NCl) catalysts, or cyclic amidine and guanidine bases (TBD or DBU) − to deliver degradation products with high yields. Further optimization of the depolymerization processes by combining catalyst innovations with the development of creative energy-efficient protocols still remains underdeveloped.…”