The importance of accurate and precise molecular weight measurement in pulsed‐laser polymerization

Abstract

Molecular weight distributions generated by pulsed‐laser polymerization have been determined experimentally using multi‐detector size exclusion chromatography (SEC). The conditions for accurate and precise SEC have been defined. The importance of the inter‐detector delay (IDD) is stressed and two different methods of defining IDD are compared. In addition this work highlights the problems associated with the use of Mark‐Houwink constants in constructing a universal calibration curve. Some preliminary results obtained from matrix‐assisted‐laser‐desorption‐ionisation mass spectrometry are also presented.

Towards a Quantitative Interpretation of Polymer Distributions from MALDI‐TOF Spectra

“…Broad distributions are of special interest for kineticists who try to extract, e.g., rate constants of chain propagation in free radical polymerization from the shape of multimodal distributions. [1][2][3][4][5][6][7] This paper addresses the possibly introduced bias regarding the shape of the polymer distribution and the average values of molar masses depending on the chosen experimental conditions as well as the data treatment. The severity of bias effects is determined experimentally and is discussed on the basis of fundamental considerations regarding mass calibration and signal intensity processing.…”

Pulsed initiation polymerization as a means of obtaining propagation rate coefficients in free-radical polymerizations. II Review up to 2000

“…[74,129] The group of Davis investigated the molecular weight of the resulting polymer from a PLP experiment of MMA with matrix-assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS), [17,95] and the possibilities of using visible light in the PLP experiment [120,130] to make the experiment suitable for otherwise strongly UVabsorbing monomers like substituted styrenes and Nvinylcarbazole and studied several copolymerizations and terpolymerizations. [90,92,94,113,121] Furthermore they studied homopolymerizations of alkylmethacrylates, [131] substituted styrenes [93] and solvent effect.…”

Theory of Multiple‐Detection Size‐Exclusion Chromatography of Complex Branched Polymers

“…Using multiple detection SEC, it is important to correct for inter-detector delay; this problem is not treated in the present work since it is already detailed in the literature. [35][36][37] All the equations are derived taking band broadening into account, and then simplified for the case when band broadening is negligible or corrected. We thus treat four different cases depicted in Figure The reason that it may be necessary to include the possibility of band broadening is the following.…”