Photodsc analysis of UV-curable hydrogels

Photopolymerization is a widely used technique to synthesize polymers and hydrogels. The commonly used ultra-violet (UV)-curable mono-, di- or multifunctional vinylated monomers or macromonomers are often volatile, causing difficulty in the accurate measurement of reaction kinetics using Photo Differential Scanning Calorimetry (PhotoDSC). In this work, the DSC sample pan is chemically and physically modified such that the resin sample can be laid uniformly in the sample pan with minimum sample weight loss during measurement. Such treatment substantially improved experimental accuracy for volatile materials, which in turn provides a better understanding of the reaction kinetics of UV-curable polymers. Kinetic experiments are carried out for poly(2-hydroxyethyl methacryate) (HEMA) and poly(methacrylic acid) (MAA) based hydrogels by using PhotoDSC and modified sample pans.