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.

Designed to Degrade: Tailoring Polyesters for Circularity

“…The conjugated vinyl structure of cinnamic acid allows the compound to dimerize under UV light, forming a cyclobutene structure in one of two possible conformations. 215 By performing substitutions of the carboxylic acid unit, a range of different cinnamoyl derivatives can be achieved, the most common being cinnamate or cinnamamide. By changing the substituents, the light required for dimerization and cleavage will also change, but generally, light in the region of 260−300 nm is used.…”

“…Cinnamic acid is a biobased and biocompatible compound that can be isolated from cinnamon bark and other biomass resources. The conjugated vinyl structure of cinnamic acid allows the compound to dimerize under UV light, forming a cyclobutene structure in one of two possible conformations . By performing substitutions of the carboxylic acid unit, a range of different cinnamoyl derivatives can be achieved, the most common being cinnamate or cinnamamide.…”