Learning Nature: Recyclable Monomers and Polymers

Abstract

Recycling processes (such as carbon, oxygen, nitrogen cycles etc.) occur each day as an essential character for nature. Managed ecosystems have maintained the natural environment in a state of great harmony for millions of years. In recent decades, various polymers with long-term durability have been developed to be the most predominantly used materials, and have drastically changed the lifestyle of human beings. However, the tremendous growth of plastic debris, with no or very low degradability, over the past decades significantly affects the natural environment. The use of alternative recycling materials is the best option from the environmental point of view. This critical review highlights the most significant progress in chemically recyclable materials, especially several typical systems, which embody perfect recycling between polymers and the starting monomers.

Living Coordination Polymerization of a Six‐Five Bicyclic Lactone to Produce Completely Recyclable Polyester

“…Zuschriften e-CL) measured by 1 HNMR was close to the calculated ratio (56 mol % e-CL) based on the monomer conversion data. The well-defined diblock copolymer structure was also confirmed by 13 CNMR analysis ( Figure S10), which showed the presence of only two types of carbonyl resonances attributed to homo-sequences of e-CL and M1 units of copolymer P(M1)b-PCL. Thet hermal property of the diblock copolymer was analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).…”

“…Chemically recyclable polymers [1][2][3][4][5][6][7][8][9][10][11][12] have attracted increasing attention in recent years because they allow for recovery of the building block chemicals via depolymerization or creative repurposing through generation of value-added materials,t hus offering af easible solution to the end-of-use issue of polymeric materials and providing ac losed-loop approach towards ac ircular materials economy. [13] However, three key challenges still remain before this approach becomes technologically and economically competitive: energy input, depolymerization selectivity,a nd depolymerizability/performance tradeoff.…”

High-performance pan-tactic polythioesters with intrinsic crystallinity and chemical recyclability

“…To address this global challenge, the design of next-generation polymers must consider their afterlife issues and establish closedloop life cycles toward a circular economy (4)(5)(6)(7)(8). In this context, the development of chemically recyclable polymers that can be depolymerized back to their monomer building blocks in high selectivity and purity for virgin-quality polymer reproduction offers a circular economy approach to address these dire environmental and economic issues (9)(10)(11)(12)(13)(14)(15)(16). For example, the ring-opening polymerization (ROP) of unstrained -butyrolactone (GBL) leads to polyester poly(GBL) that can be completely depolymerized back to GBL in quantitative purity and yield with a low energy input (17,18).…”

Catalyst‐Sidearm‐Induced Stereoselectivity Switching in Polymerization of a Racemic Lactone for Stereocomplexed Crystalline Polymer with a Circular Life Cycle

“…Chemically recyclable polymers [1][2][3][4][5][6][7][8][9][10][11][12][13] have lately attracted growing attention because their building block chemicals,o r monomers,c an be recovered for the production of virgin plastics with the same qualities as the original, thus offering af easible solution to the end-of-use issue of polymeric materials and providing ac losed-loop approach towards acircular materials economy. [14] However, there is aparadox between the ability to depolymerize and performance,where polymers that can be readily depolymerized back to monomers often lack physical properties and mechanical strengths to be widely useful, and vice versa.…”