A PLP‐SEC Investigation of Di(Ethylene Glycol) Methyl Ether Methacrylate Radical Polymerization Propagation Kinetics in Solution

ABSTRACT The pulsed laser polymerization size exclusion chromatography (PLP‐SEC) technique is used to explore the impact of solvent polarity and composition—from bulk to ethanol (EtOH) /water mixtures to aqueous solutions and dimethyl sulfoxide (DMSO)—on the homopropagation kinetics of di(ethylene glycol) methyl ether methacrylate (DEGMEMA) between 30 and 90°C. The variation in the propagation rate coefficient ( k p ) is attributed to entropic factors, as the activation energy remains approximately constant across all solvent mixtures at a value characteristic of other methacrylates (∼ 21 kJ·mol −1 ). The exception to this generalization is for EtOH, where activation energy is lowered by 3–4 kJ·mol −1 , and the k p for a solution containing 50 wt.% DEGMEMA is lower than the bulk values. DEGMEMA k p values increase as monomer content is decreased from 50 to 10 wt.% in DMSO, EtOH, and EtOH/H 2 O solvents. Most notably, the k p of 5 wt.% DEGMEMA in water (close to its solubility limit) is higher by a factor of 12 compared to the bulk system. These new results for a member of the PEGylated monomer family also provide insight into the increase in chain‐growth rates expected for non‐functional methacrylates between bulk (i.e., particle) and aqueous phases in emulsion polymerization systems.