Electron spin resonance (ESR) estimation of propagation rate constants of radical polymerization of butyl methacrylate

Propagation rate constants (k_p) for the free radical polymerization of butyl methacrylate (BMA) in toluene solution were measured by ESR spectroscopy in the temperature range from –30 to 90°C. The polymerization was photochemically induced at a constant initiator concentration of di‐tert‐butyl peroxide (tBPO). The Arrhenius parameters A and E_a were estimated to be (3.40 ± 0.4)>×10⁶ M^–1·s^–1 and (22.0 ± 1.0) kJ/mol, respectively. The k_p values estimated from ESR analysis were compared with the corresponding data obtained from the pulsed laser polymerization (PLP).