Water-Soluble Reversible Photo-Cross-Linking Polymer Dielectrics

Macromol Rapid Commun. 2024 Aug;45(16):e2400205. doi: 10.1002/marc.202400205. Epub 2024 Jun 28.

Abstract

Effective recycling of mixed materials requires the separation of the different components without the need for toxic solvents. One approach involves utilizing a water-soluble coating with reversible photo-cross-linkers, making it robust until end of life where it can then be dissolved in water after de-cross-linking. Here, a novel coumarin methacrylate monomer and its nitroxide-mediated copolymerization to create poly((methacrylic acid)-co-(styrene sulfonate)-co-(coumarin methacrylate)) for water-soluble thin films are reported. Under exposure to light, the coumarin functional groups produce reversible [2+2] cycloadditions which cross-link the resulting polymer films, making them no longer water soluble. Characterization of reversible cross-linking behavior is reported through changes in contact angle and in situ rheological characterization. The resulting polymers are successfully integrated into metal-insulator-metal capacitors, demonstrating the potential use for water-soluble reversible photo-cross-linkable dielectric materials for organic electronics.

Keywords: dielectrics; nitroxide‐mediated polymerization; photoreversible; photo‐cross‐linking.

MeSH terms

  • Coumarins / chemistry
  • Cross-Linking Reagents / chemistry
  • Methacrylates / chemistry
  • Molecular Structure
  • Photochemical Processes
  • Polymerization
  • Polymers* / chemistry
  • Solubility*
  • Water* / chemistry

Substances

  • Water
  • Polymers
  • Cross-Linking Reagents
  • Methacrylates
  • Coumarins