Determination of Propagation Rate Coefficients of a Family of Acrylates with PLP-MALDI-ToF-MS

The combination of MALDI-ToF-MS with pulsed laser polymerization (PLP) has one big advantage over the combination of size exclusion chromatography (SEC) with PLP. MALDI-ToF-MS is an absolute measurement which does not need calibration. Especially in the field of acrylates, this is an important advantage over the conventional use of SEC, since low polydispersity standards are not readily available for acrylates. Moreover, acrylates suffer from branching. Literature shows that since branched polymers have a different hydrodynamic volume than linear polymers, this can affect the calibration of SEC. The determination of the Arrhenius parameters for a family of acrylates is performed with PLP-MALDI-ToF-MS. The results clearly demonstrate that an increase of the ester side group indeed results in an increase of the propagation rate coefficient. Whether this is due to an entropic or enthalpic effect cannot be derived from the results.