Competition between Phase Separating and UV Curing Kinetics during Photopolymerization-Induced Phase Separation in Confined Resin Films

Polymerization-induced phase separation is the segregation of agents in a multicomponent mixture triggered by polymerization to convert low molecular weight (MW) monomers into high MW polymers or networks. Several factors control the nature and structure of polymerization-induced phase separation, including blend composition, molecular weight of the phase separation agent, and polymerization kinetics of the monomers. When properly controlled, these factors can dictate a specific morphology of the resulting structure, allowing for tuning of characteristics of the resulting network. This study seeks to investigate these factors during photopolymerization-induced phase separation. Real-time turbidity to measure UV light transmittance through a blend sample of predetermined thickness will be employed as the main tool to monitor the phase separation process during UV irradiation. UV LED intensity and wavelength, resin reactivity, and end functionality of polymer additives will be studied to investigate the effect of each on the phase separation process and resulting network morphology within the confined space of UV-curable resin films. Scanning electron microscopy and other microscopy tools will be used for the study of morphology for the photopolymerization-induced phase separation.