Transfer Reactions in Phenyl Carbamate Ethyl Acrylate Polymerizations

Abstract

The transfer reactions occurring during polymerization of 2‐(phenylcarbamoyloxy)ethyl acrylate (PhCEA) were studied by a detailed product mapping with electrospray ionization mass spectrometry (ESI‐MS). Unlike postulated before, PhCEA exhibits the same characteristic transfer reactions as other acrylic monomers at elevated temperatures, resulting in vinyl‐terminated and saturated products. Transfer to monomer via abstraction of a hydrogen atom from the ester side chain as suggested before is not observed. When polymerized in a poly(ethylene glycol) (PEG) matrix to increase viscosity, transfer into matrix products are observed in minor amounts, demonstrating that PEG can be employed as a solvent to further increase the overall rate of polymerization without interference from side reactions.

Global Trends for kp? Expanding the Frontier of Ester Side Chain Topography in Acrylates and Methacrylates

“…Additionally, the MCR can undergo several follow-up reactions such as migration of the radical site along the polymer backbone or β-scission (which can, e.g., be employed to generate macromonomers). 44,45 A possible method to compensate for the loss of the PLP structure in the SEC chromatograms would be the application of an even higher pulse repetition rate. Unfortunately, laser systems with pulse repetition rates exceeding 500 Hz have not yet become available at the wavelength of 351 nm.…”

“…This acrylate typical behavior in the high temperature region is due to the increasing frequency of transfer to polymer reactions such as backbiting and the consequently increasing influence of the propagation rate coefficient of the midchain radicals (MCR), k p MCR . ,, The propagation of the MCRs, arising from intra- and intermolecular transfer to polymer, generates short and long chain branching, respectively, depending on the type of transfer process. Additionally, the MCR can undergo several follow-up reactions such as migration of the radical site along the polymer backbone or β-scission (which can, e.g., be employed to generate macromonomers). , A possible method to compensate for the loss of the PLP structure in the SEC chromatograms would be the application of an even higher pulse repetition rate. Unfortunately, laser systems with pulse repetition rates exceeding 500 Hz have not yet become available at the wavelength of 351 nm .…”

The Kinetics of n‐Butyl Acrylate Radical Polymerization Revealed in a Single Experiment by Real Time On‐line Mass Spectrometry Monitoring

“…Next to the vast number of synthetic studies, fundamental research has also been dedicated to the detailed study of the mechanism and kinetics of the underpinning radical chain reactions. Acrylates—as one of the most used monomers, and in particular n ‐butyl acrylate ( n BA)—have been investigated in great detail. Acrylate polymerizations differ significantly from the ideal free radical polymerization (FRP) reaction scheme especially at elevated temperatures.…”