Itaconic acid as an effective biobased platform molecule for vat photopolymerisation additive manufacturing

*Centre for Materials Engineering, Department of Mechanical Engineering, University of Cape Town, South Africa.

^* Corresponding author: james.dicks@uct.ac.za

Abstract

The successful development of renewable feedstocks for monomer and oligomer synthesis has remained limited in its achievable biobased content, and often still rely on toxic compounds for functionalisation (e.g., acrylates). As such, the viability of itaconic acid as an abundant, cheap, and highly sustainable source of functionalisation for free radical polymerisation was explored to overcome these issues. Itaconic acid presented itself as a versatile α,β-unsaturated carbonyl diacid with the ability to be incorporated into monomers via several facile and sustainable synthesis pathways. Owing to these attributes, a novel monomer system composed of an unsaturated polyester oligomer and a castor oil derived monomer were developed and used alongside isobornyl methacrylate as a commercially available biobased reactive diluent for additive manufacturing. This system was demonstrated as an effective combination to achieve tailorable resins for masked stereolithography additive manufacturing with desirable mechanical properties, whilst maintaining a high sustainability.