Cinnamic acid derivatives as promising building blocks for advanced polymers: synthesis, properties and applications
Cinnamic acid (CA) and its hydroxy-derivatives are aromatic building blocks whose structural peculiarities (unsaturation, hydroxylic and/or carboxylic groups) have driven them to a prominent position in polymer science. Indeed, CA hydroxy-derivatives (hydroxycinnamic acids, HCAs) have been extensively used in the preparation of polyesters, but there are also reports about their use in the synthesis of polyamides and poly(anhydride esters), among many other uses. It is worth mentioning that these polymers have a wide spectrum of applications, ranging from industrial (e.g. (super-)engineered plastics) to biomedical domains (e.g. drug delivery systems, shape-memory materials). Despite the well-known importance of CA-based polymers and the extensive activity around their synthesis and development, to the best of our knowledge, there are no reviews devoted solely to this theme. Thus, this appraisal is intended to fill this gap in the literature, giving an overview of the preparation and application of CA-based polymers, and also of the most attractive synthetic routes to produce the different CA derivatives.