Photopolymerization-Induced Phase Separation in a Polypropylene Glycol-Modified Dimethacrylate System

The effect of polypropylene glycol (PPG) on the phase structure formation and deformation properties of a photocurable system based on bisphenol-A 10-ethoxylate dimethacrylate (BPADMA) was studied. Optical interferometry established the complete compatibility of the components before polymerization, and the critical PPG concentration predicted as corresponding to the center of the phase inversion region (28 vol.%) was determined. SEM confirmed the formation of the predicted phase structure, characterized by interpenetrating continuous phases. FTIR spectroscopy showed that the introduction of PPG has virtually no effect on the conversion degree (92.3% for neat BPADMA and 91.5% for BPADMA–PPG blend prepared by volume). The enhanced deformation capacity and reduced compressive resistance are attributed to the formed phase structure.