-Advanced Polymer Monitoring Technologies, Inc.
-Polymer Standards Service
-WGE Dr Bures
-Brookhaven Instruments Corp.
-International Specialty Products
non-chromatographic monitoring and discrete chromatographic monitoring were
coupled together for the first time and used to monitor free radical and
controlled radical polymerization reactions. This was achieved by adding a
multi-detector Size Exclusion Chromatography (
Kinetics from two different types of reactions, Reversible Addition Fragmentation Transfer (RAFT) and free radical polymerization of butyl acrylate were studied, including the production of a bimodal population.
- Addition of multi-detector
- The ability of the SEC approach to furnish meaningful molecular weight distributions will depend both on the details of the reaction and which column(s) are used. In the current work a single column was not able to directly resolve a narrowly separated bimodal distribution, but the resulting distribution could be resolved into bimodal components with a model dependent assumption.
- In the initiator boost reaction
here, the continuous, non-chromatographic approach was able clearly to detect
the onset of
- ACOMP-SEC will also be well
suited for living reactions that are slow, so that more data points per unit of
conversion can be obtained.
- Using small pore columns, the
ACOMP signals change as the reaction proceeds
SEC Detectors follow the reaction at the same time
Bimodal molecular weight distributions in free radical reactions. Frequently, extra initiator is added during free radical reactions, sometimes to ensure reaction completion or to 'scavange' residual monomers. Such initiator 'boosts' can also produce bimodality in the WMD, if the initiator is added at early or intermediate levels of conversion.
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