Propagation rate coefficients are provided—for the first time—for an entire class of urethane moieties containing acrylates, which display an extremely high propagation rate.

Optimization of holography recording in photopolymers was studied from the point of view of a quite general process, that is, the photogeneration of radicals. On the basis of a dye/coinitiator photoinitiating system, the effect of primary events and their relative efficiency was investigated with respect to the final overall properties, such as the diffraction efficiency. Quenching of the dye excited states by the borate salts coinitiators exhibits important differences depending on the dye used (Rose Bengal or Safranine O). Keeping in mind that both singlet and triplet states of the dyes can react, and taking into account the viscosity of the matrix, a method to evaluate the overall quantum yield of radicals released is proposed. It is found that this quantum yield well correlates with the maximum rate of photopolymerization. More interestingly, the dose required to obtain a given diffraction efficiency was found to be also governed by the radical quantum yield, showing that the final property is directly governed by primary events. This shed some light on the efficiency of photochemical pathway to generate radicals for use in organic or polymer areas.

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.

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