Progress and Challenges of Using Itaconic Acid for Sustainable, Competitive and Advanced Polymers in Additive Manufacturing

Despite efforts to develop polymeric materials using renewable feedstocks, there is a continued reliance on (meth)acrylates for several additive manufacturing (AM) technologies, diminishing their overall sustainability. On the other hand, itaconic acid presents itself as an opportunity to resolve these shortcomings as a biobased source of unsaturation, produced through enzymatic transformation of starches. A variety of unsaturated oligomers (e.g., poly[ester], poly[ester amide] and poly[ester thioether]) and monomers (e.g., monoesters, diesters, hydroxyesters and non‐isocyanate urethanes) have been developed and used in various AM technologies. These materials have been demonstrated across a broad scope of applications, from mechanically competitive materials and nanoparticle‐reinforced composites to self‐healing and shape memory polymers, as well as biocompatible and biomedical materials. Despite this encouraging progress, however, the synthetic transformations of itaconic acid as well as processing considerations for AM have made advancement within the field a non‐trivial task. Herein, the use of itaconic acid is critically examined, highlighting the diversity and challenges of sustainable synthetic avenues, processing constraints in AM, and achieving competitive and advanced materials applied across a range of AM technologies and useful within several important contemporary engineering fields.