Carbon fiber-reinforced polymer (CFRP) composites are commonly used in aerospace, wind turbine, and automotive manufacturing. Here, we are working to recycle these CFRP composite materials via a chemical depolymerization approach that maintains the integrity of the woven carbon fibers and returns monomers from the polymer matrix. We show that photocatalytic generation of singlet oxygen (1O2) enables rapid oxidative depolymerization of composites that is not feasible with triplet oxygen conditions. To use 1O2 in the recycling process, it must intercalate into a solid, cured epoxy resin. To show how intercalation occurs, we created 1 cm3 blocks of the epoxy-resin that is used to cure CFRPs which we have infused with the 1O2 detector trans-1-(2’-methoxyvinyl)pyrene (MVP). We then reacted the sample in our CFRP recycling reaction conditions under 1O2 and imaged internal cross-sections of the cube using confocal fluorescence microscopy. Visualizing oxygen intercalation through the resin allows us to identify the best depolymerization conditions for recycling CFRPs. We are currently developing this reaction toward an industrial process that will conserve valuable CFRP materials, energy, money, and will improve environmental impacts from the current waste disposal methods.

Tracking singlet oxygen reactivity for chemical composite recycling

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.