Interplay of Photo-Polymerization and Phase Separation Kinetics in 3D Printing Using PEG & Methacrylated PEG

Photo-polymerization-induced phase separation would serve as a useful strategy to tailor the physical properties of 3D printed porous materials. The interplay between photopolymerization kinetics and phase separation can be studied using a multiscale method to show the extent of phase separation and its overall effect on the material once 3D printed. UV transmittance experiments are performed as a main characterization method using a custom-built light transmission apparatus. Additional characterizations such as polarized optical microscopy and scanning electron microscopy have been used to understand the morphology of polymer films. In particular, vegetable oil-based monomers are considered as a base of photocurable resin as they are sustainable and recyclable. Polyethylene glycol (PEG) and PEG methylether methacrylate (PEGMEM) are used as polymer additives. PEG-containing resins show a drastic increase in turbidity upon photopolymerization, while the PEGMEM-based resins do not. The grafting of PEGMEM during the photopolymerization serves as a surfactant for the system, thus reducing phase separation effects and altering the physical properties of the material.