Novel monomers for photopolymer networks

Photopolymerization technology to transform monomers into polymer network materials has been widely applied to enable various conventional and emerging applications such as dentistry, coatings, adhesives, holography, optics, microelectronics, and 3D printing, to name but a few. Monomers play a critical role both in determining the properties of photopolymers and, thus, their ultimate applications. This review article highlights the recent progress in the development of novel monomers which can be used in photopolymerization for advanced materials design. An overview on some of the fundamental concerns for the demand of novel monomers is given first. Subsequently, recent progress towards novel (meth)acrylate monomers for free radical polymerization, monomers for thiol-ene polymerization, and epoxide monomers for ring-opening cationic polymerization are summarized and the structure-property relationships of the resulting photo-crosslinked polymers are discussed. Furthermore, recent innovations of novel photo-controlled reaction types for photopolymer network formation such as polymerization initiated by photobase generation and photo-click reactions are discussed. The review aims to not only provide researchers an up-to-date survey of monomers for the design of functional photopolymer materials but also inspire advances in the development of monomers that will enable the development of high-performance functional photopolymer network materials.