Thiol-Ene Photopolymerization and 3D Printing of Non-Modified Castor Oil Containing Bio-Based Cellulosic Fillers

Author(s)

Alarcon, Rafael Turra ; Bergoglio, Matteo ; Cavalheiro, eder Tadeu Gomes ; Sangermano, Marco

• Document type: Journal article
• Source: POLYMERS; v. 17, n. 5, p. 19-pg., 2025-03-01.

Abstract

The photopolymerization process in 3D printing is considered greener once it involves a fast reaction and low energy consumption. Various reactions for photopolymerization can be used nowadays, but a special one is the thiol-ene "click" reaction that occurs in equimolar concentrations of thiol and alkene groups. In this sense, solvent-free photopolymerizable formulations were prepared to contain non-modified castor oil, Trimethylolpropane tris(3-mercapto propionate), and cellulosic fillers from hemp, tagua, and walnut. All formulations presented conversions higher than 70% and fast polymerization rates. Moreover, the filled formulations presented excellent curing depths in fewer seconds of light exposition, an important factor for their applicability in 3D printing. Furthermore, the hemp filler formulation presented the highest crosslinking density as determined by the DMTA, and was selected for printing two complex structures (pyramid and honeycomb shape). The rheology analysis showed that the formulations had adequate viscosities for the printer. Lastly, all polymers presented at least 97% bio-based contents, with gel contents superior to 96%. (AU)

• FAPESP's process: 24/03936-1 - Synthesis of biobased photocurable resin and exploitation in 3D printing
• Grantee: Rafael Turra Alarcon
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 22/15211-6 - Preparation and Application of Composite Electrodes Based on Graphite and Polymers: miniaturization, screen printed electrodes and flexible sensors
• Grantee: Éder Tadeu Gomes Cavalheiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/14879-0 - New synthetic method of poly-hidroxyurethanes from triacylglycerol using catalysts or triacylmelamine to inhibition side reactions
• Grantee: Rafael Turra Alarcon
• Support Opportunities: Scholarships in Brazil - Post-Doctoral