Photoinitiating systems and kinetics of frontal photopolymerization processes – the prospects for efficient preparation of composites and thick 3D structures

In recent years, frontal polymerisation has found a growing interest in many applications. Thus, its ability to cure thick samples with different fillers up to 50% by local application of a reasonable portion of energy makes this polymerisation approach very promising. It can find many applications in materials science and industry as well as in the preparation of 3D structures. Herein, we present recent achievements in the field of frontal photopolymerisation and phototriggered frontal thermal polymerisation. A light application allows full control of the curing process. The combination of frontal polymerisation and light curing provides a convenient and versatile method to trigger frontal polymerisation, especially in heat sensitive materials or dentistry applications. Moreover, in this review, we focused on the photoinitiating systems in frontal polymerisation, their mechanism of action, components, and applications, dividing them according to the type of polymerisation: free-radical polymerisation, ring-opening cationic polymerisation and other minor types.