Pulsed Laser Polymerization of Styrene in Microemulsion: Determination of Band Broadening in Size Exclusion Chromatography with Multimodal Distributions

Summary: Styrene was polymerized in microemulsion by pulsed laser radiation. The resulting multimodal distributions are composed of equidistant Poisson distributions as bimolecular termination occurs mainly during the short laser pulses. For nearly all distributions the first peak was almost base line separated and higher order peaks were clearly distinguishable. The width of the first and second peak was used to determine the extent of band broadening (bb), σ , as a function of the retention volume. Results were collected for three combinations of columns differing in their separation range. These values and those obtained from anionically polymerized polystyrene standards show the same dependence on the retention volume and can be described by the van Deemter equation even beyond the exclusion limit. The results are interpreted in the context of obstructed diffusion and the van Deemter equation is extended to take into account the contribution of the individual columns with different pore sizes. Both theory and experiment advocate a non‐uniform bb thus emphasizing the necessity for the determination of bb for a given set of columns. Comparison of experimental results (squares – standards, circles PLP‐ME samples) and theory (full line: according to Equation ( 6c ), broken lines: individual contributions of the columns). magnified image Comparison of experimental results (squares – standards, circles PLP‐ME samples) and theory (full line: according to Equation ( 6c ), broken lines: individual contributions of the columns).