Interfacial Photocycloaddition Polymerization: Synthetic Approach of Structurally Functionalized Degradable Polymer Particles from Naturally-derived Monomers

Industrially relevant polymer capsules—structurally functionalized particulate materials that have shown promise for application in cosmetics, fragrances, and agrochemicals—typically comprise non-degradable synthetic polymers that cause marine microplastic pollution, which is a global environmental issue. This paper describes the synthesis of structurally functionalized degradable polymer particles by photolysis and hydrolysis without any initiators or catalysts via interfacial photocycloaddition polymerization of natural product-derived photoreactive monomers in aqueous heterogeneous systems. The resultant polymeric particles stably encapsulate dyes and fragrance molecules and decompose into naturally occurring raw materials. The reaction wavelengths for interfacial photocycloaddition polymerization (for capsule synthesis) and retro-photocycloaddition (for photodegradation) can be regulated using photoreactive monomers with appropriate substituents. Moreover, scaled-up synthesis of the polymer capsules is possible using high-power light-emitting diode lights. This technology is expected to expedite the design of an innovative synthesis method for resource-recycling polymer capsules that can contribute toward the realization of a sustainable society.