Synthesis of biobased functional materials using photoactive cinnamate derivatives

Abstract The use of cinnamic acid provides an approach to the research and development of biobased plastics for the reduction of global warming caused by the increasing amounts of carbon dioxide in the atmosphere. Cinnamic acids in the metabolic systems of plants and microorganisms have been extensively studied. These cinnamates are reactive to ultraviolet (UV) light, and polymers based on these acids exhibit unique properties. In this focus review, we describe our recent work on the development of materials based on cinnamates. Polyesters are obtained by the polycondensation of hydroxycinnamic acid abundant in plants. The amorphous polycinnamate films exhibit characteristic photodeformability upon UV irradiation owing to E-Z isomerization and [2 + 2] cycloaddition reactions. The [2 + 2] cycloaddition reaction of cinnamate can also be used to obtain truxillic and truxinic acids with excellent symmetry. Using these truxillic/truxinic acids, organic solvents or water-soluble polyimides and high-strength polyamides with high transparency can be derived, and biobased plastics comparable to existing high-performance plastics can be obtained.