The article "Depolymerization and Re/Upcycling of Biodegradable PLA Plastics" by YingChao Li et al. addresses the growing environmental concerns and recycling challenges associated with plastic waste, particularly focusing on biodegradable plastics like polylactic acid (PLA). PLA, a widely used biodegradable plastic, faces obstacles such as high costs, low recycling rates, and incomplete degradation in natural conditions. The review highlights the importance of exploring solutions for the depolymerization and re/upcycling of PLA waste plastics, emphasizing the advantages and significance of chemical re/upcycling methods. The introduction discusses the properties and applications of plastics, the global plastic production, and the environmental impact of plastic waste. It highlights the emergence of biodegradable plastics like PLA due to their sustainability and biodegradability. PLA is noted for its versatility in various industries, including thin films, medical materials, and textiles, but it also faces challenges such as high synthesis costs and limited degradation rates in natural environments. The article then delves into the current methods of PLA recycling, including mechanical, energy, and chemical recycling. Mechanical recycling involves transforming discarded plastic into new products, while energy recovery involves direct combustion of plastic waste. Chemical recycling, particularly chemical re/upcycling, is highlighted as a more sustainable approach, as it breaks down PLA into monomers or other valuable chemicals. The review covers various chemical depolymerization methods, including pyrolysis, hydrolysis, alcoholysis, and enzymatic hydrolysis. Pyrolysis, while efficient, faces challenges such as high reaction temperatures and complex output. Hydrolysis, an environmentally friendly method, requires careful optimization of reaction conditions to achieve high monomer purity. Alcoholysis, using alcohol molecules as solvents, yields valuable precursors like methyl lactate. Enzymatic hydrolysis, facilitated by microorganisms, is a promising method for biodegradation but is limited by the time required for complete degradation. The article also explores other methods such as aminolysis, reductive/oxidative depolymerization, photolysis, and electrolysis, each with its own advantages and challenges. The conclusion emphasizes the importance of closed-loop recycling and upcycling, highlighting the need for efficient and cost-effective processes to promote sustainable practices in the PLA industry. Overall, the review provides a comprehensive overview of the current landscape of PLA recycling methods, emphasizing the pursuit of closed-loop recycling and upcycling to address the challenges and opportunities in the PLA plastics sector.The article "Depolymerization and Re/Upcycling of Biodegradable PLA Plastics" by YingChao Li et al. addresses the growing environmental concerns and recycling challenges associated with plastic waste, particularly focusing on biodegradable plastics like polylactic acid (PLA). PLA, a widely used biodegradable plastic, faces obstacles such as high costs, low recycling rates, and incomplete degradation in natural conditions. The review highlights the importance of exploring solutions for the depolymerization and re/upcycling of PLA waste plastics, emphasizing the advantages and significance of chemical re/upcycling methods. The introduction discusses the properties and applications of plastics, the global plastic production, and the environmental impact of plastic waste. It highlights the emergence of biodegradable plastics like PLA due to their sustainability and biodegradability. PLA is noted for its versatility in various industries, including thin films, medical materials, and textiles, but it also faces challenges such as high synthesis costs and limited degradation rates in natural environments. The article then delves into the current methods of PLA recycling, including mechanical, energy, and chemical recycling. Mechanical recycling involves transforming discarded plastic into new products, while energy recovery involves direct combustion of plastic waste. Chemical recycling, particularly chemical re/upcycling, is highlighted as a more sustainable approach, as it breaks down PLA into monomers or other valuable chemicals. The review covers various chemical depolymerization methods, including pyrolysis, hydrolysis, alcoholysis, and enzymatic hydrolysis. Pyrolysis, while efficient, faces challenges such as high reaction temperatures and complex output. Hydrolysis, an environmentally friendly method, requires careful optimization of reaction conditions to achieve high monomer purity. Alcoholysis, using alcohol molecules as solvents, yields valuable precursors like methyl lactate. Enzymatic hydrolysis, facilitated by microorganisms, is a promising method for biodegradation but is limited by the time required for complete degradation. The article also explores other methods such as aminolysis, reductive/oxidative depolymerization, photolysis, and electrolysis, each with its own advantages and challenges. The conclusion emphasizes the importance of closed-loop recycling and upcycling, highlighting the need for efficient and cost-effective processes to promote sustainable practices in the PLA industry. Overall, the review provides a comprehensive overview of the current landscape of PLA recycling methods, emphasizing the pursuit of closed-loop recycling and upcycling to address the challenges and opportunities in the PLA plastics sector.