Tunable conversion of poly(acrylic acid) to vinyl methyl ether copolymers via electrochemical decarboxylation

Recognizing the potential of polymer-to-polymer transformations for plastics valorization, a new electrochemical strategy for the decarboxylative functionalization of polyacrylates has been developed.In contrast to most electrochemical approaches to plastic waste valorization that use small-molecule mediators or only form deconstruction products, this report describes one of the first direct electrochemical redox upconversions of a commodity polymer and involves activation of poly(acrylic acid), a material commonly found in disposable diapers and other personal hygiene products.Via electrochemical decarboxylation, poly(acrylic acid) is converted to methyl ethercontaining copolymers.Although methods to prepare the 1:1 regularly alternating poly(vinyl methyl ether-alt-maleic anhydride) are known, routes to generate copolymers with variable levels of vinyl methyl ether and acrylate moieties are unknown, but such polymers may have utility in similar applications, such as dentifrices.Tunable conversions with up to 62 mol% vinyl methyl ether content were achieved via controlled-current electrolyses at >100 mA.This approach enables efficient access to copolymers with broad range of comonomer content from a common waste polymer starting material.Poly(acrylic acid) (PAA) is a widely used macromolecule that, once cross-linked, results in a super absorbent polymer (SAP) with utility in diapers and feminine hygiene products.1 These single-use products currently constitute a tremendous landfill burden, accounting for as much as 21 wt% of municipal solid waste in some countries.2,3 Although PAA is hardly recycled, methods to deconstruct or valorize PAA could open avenues to give PAA and SAPs a second life.Thermomechanical recycling methods are generally precluded for SAPs because crosslinked PAA does not melt, and deconstruction is difficult because uncontrolled decomposition pathways dominate and generate many unwanted byproducts.4,5 Thus, it is desirable to find methods of converting PAA into other valuable polymers for further use.There are a limited number of methods available to convert PAA to other polymers.Existing strategies primarily rely on photochemical or thermal methods to either generate new polymers