In situ monitoring of photo-crosslinking reaction of water-soluble bifunctional macromers using magnetic levitation

Crosslinking is one of the fundamental phenomena in polymer science, which happens by forming covalent bonds or relatively short sequences of chemical bonds to join two polymer chains. Crosslinking and the subsequent volume shrinkage of monomers/macromers result in changes in their corresponding density which can be measured using density-based measurement techniques (e.g., dilatometry). Here, we demonstrate a method that allows in situ monitoring of photopolymerization of water-soluble bifunctional macromers using magnetic levitation (MagLev) system. We use a hydrophobic paramagnetic solution to monitor the photopolymerization of water-soluble polyethylene glycol diacrylate (PEGDA) as a model of bifunctional macromers using a ring MagLev system. Based on changes in levitation heights (densities) after illumination of blue light, we have successfully monitored the double bond conversion of PEGDA 700 macromers at various polymerization conditions. Our findings suggest that MagLev can be used as a new and complementary analytical technique for rapid screening of the photopolymerization reactions and measurement of conversions using changes in the levitation height of the macromers. [Display omitted] •Monitoring of photo-cross linking of macromers using magnetic levitation (MagLev) system.•Developing a hydrophobic paramagnetic solution to monitor the photopolymerization of water-soluble macromers.•Estimating the density of polymers using MagLev system.•Finding the correlation between the levitation heights of the polymers and the conversion using a portable ring MagLev system.