Conversion profiles (Figure ) were measured using the 1 H spectrum at four light intensities. In Figure , these conversion profiles are shown on a logarithmic scale wherein the initial slope (first 10 seconds) yields the apparent rate constant (kp') of the polymerization reaction, according to the pseudo steady state approximation. The apparent rate constant kp' is a combination of multiple kinetic constants including the propagation rate constant inherent to the reaction (k p ), the quantum yield, the rate constant of termination, the initiator concentration, and incident light intensity. As the light intensity is increased from 0.53 to 0.95 mW/cm 2 , we observe kp' rise from 0.04063 to 0.06745 s -1 , a 66% increase. A further increase to 1.13 mW/cm 2 results in another 30% gain in kp' and finally, progressing to the highest light intensity of 1.72 mW/cm 2 , results in another 10% increase in kp' (0.1059 s -1 ).