The influence of hydrogen bonding on the radical polymerization kinetics of methyl acrylate (MA) is studied by conducting in situ nuclear magnetic resonance and lab batch experiments in both toluene and ethanol/water (EtOH/H2O) solutions between 50 and 70 °C with initial monomer contents of 10–40 wt % and various initiator contents. While polymerization behavior is influenced by backbiting in both systems, the rate of monomer conversion was found to be significantly faster for reactions conducted in the polar solvent mixture. The experimental investigation also found that the average molar mass of poly­(MA) was significantly higher in deuterated solvents compared to protonated solvents, a result attributed to an order of magnitude reduction in the abstractability of deuterium from C–D bonds compared to hydrogen from C–H bonds. A mechanistic model that included acrylate backbiting, the influence of solvent viscosity and radical chain length on termination, and the dependency of initiator efficiency on monomer content was implemented to describe the results, with the appreciable influence of monomer content and solvent composition on MA propagation kinetics in EtOH/H2O also accounted for. The model successfully captures MA polymerization behavior (i.e., monomer conversion and final product short chain branching levels and polymer molar mass distributions) in both solvent systems over the complete range of experimental operating conditions. The systematic approach adopted provides a roadmap to study the influence of monomer content and solvent composition on other acrylate polymerizations conducted in polar media.

There is limited knowledge of the radical polymerization kinetics of partially water-miscible monomers, often used as comonomers in emulsion or solution polymerizations. Herein, the propagation kinetics of 2-methoxyethyl acrylate (MEA)...

The optimal conditions for the production of virulent bacteriophages in bioreactors can vary greatly depending on the host-bacteriophage system used. We present a general method for the production of virulent bacteriophages in bioreactors that can be adapted to many host-bacteriophage systems and various operating conditions (reactor volume, medium composition, temperature, etc.). The procedures detail how to establish optimal initial infection conditions (infection load and initial multiplicity of infection (MOI)), prepare the host pre-culture and bioreactor, operate the bioreactor, and harvest the bacteriophage product. Batch operation is detailed but a short discussion addresses other modes of operation, namely two-stage continuous bioreactors and two-stage cycling bioreactors.

The radical homopolymerization of N-tert-butyl acrylamide (t-BuAAm) and its copolymerization with methyl acrylate (MA) is studied in ethanol/water solutions over a range of initial monomer and initiator levels between 50 and 70 °C. While short-chain branching for poly(t-BuAAm) samples could not be detected by 13 C NMR, the reduced rate of monomer conversion with lowered monomer content indicates the formation of mid-chain radicals (MCR) by backbiting. Adding water as a cosolvent to ethanol significantly increases reaction rates, in agreement with recent pulsed-laser studies that quantify the influence of solvent composition on homopropagation kinetics. However, the measured drifts in comonomer composition with conversion are well represented by a single pair of reactivity ratios (r MA = 1.12 ± 0.01, r t-BuAAm = 0.71 ± 0.01) over the complete range of experimental conditions. A mechanistic model developed to describe t-BuAAm homopolymerization is extended to capture the impact of reaction operating conditions (monomer content and composition, solvent composition, initiator content, and temperature) on the features of t-BuAAm/MA copolymerization, thus providing a tool for product and process optimization. The model structure can be used to support the development of other acrylate/acrylamide systems as part of the continued efforts to utilize "green" solvents to reduce the environmental impacts of polymerization processes.

The effect of solvent on the radical copolymerization propagation kinetics of methyl acrylate (MA) with N-tert-butyl acrylamide (tBuAAm) is studied using the pulsed laser polymerization size exclusion chromatography technique (PLP-SEC),...