Poly(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA) is a potential non-immunogenic1 material for biomedical applications. However, the highly reactive free radical2 of PEGMA makes control of its polymerisation challenging. In this study, we investigated the synthesis of P(PEGMA) through photoiniferter RAFT (PI-RAFT), a promising approach to synthesise a broad range of (meth)acrylic polymers because of its highly controlled nature.3 Current studies on the PI-RAFT mechanisms are limited and the effect of the solvent on kinetics has not been reported. The apparent kp values were complicated by the involving RAFT main equilibrium. We calculated the Arrhenius parameters, enthalpy of activation (Δ𝐻‡), and entropy of activation (ΔS‡) for polymerisation in various solvents. Regression analysis was conducted to fit the results with extinction coefficients of the trithiocarbonate chain transfer agent (CTA), solvent physical properties, and solvatochromic scales. The effective collision factor A had a good fitting (adj. R2 = 0.21, p = 0.04) into an exponential regression model of the extinction coefficients, indicating a strong relationship between the rate and excitation of the CTA. Solvent polarity scales, such as Kalmet-Abraham-Taft (KAT) and Catalan parameters, failed to predict kp, Arrhenius parameters, Δ𝐻‡, and ΔS‡. The chain transfer constant Ctr > 1 for all syntheses, indicating relatively good control through degenerative chain transfer with CTA radicals. It was found that Ctr decreased with increasing temperature, a function of the rate of activation being constant, while kp increased with the temperature.