Polymerization Kinetics

Since light scattering intensity is directly proportional to molar mass, it is an excellent means of monitoring the progression of a polymerization reaction. The angular dependence of multi-angle light scattering indicates size for additional diagnostics, and dynamic light scattering may be included for further characterization.

When reaction time scales are significantly longer than the time required to perform a separation (typically 30 minutes), the ideal means of characterizing the polymerization process is regular withdrawal of aliquots from the reaction vessel and analysis by means of SEC-MALS. Reactions over shorter times must necessarily be evaluated in batch (unfractionated) mode which provides average molar masses and sizes rather than full distributions. The Calypso composition-gradient system is a convenient means of preparing, mixing and injecting multi-component solutions into a MALS system such as the DAWN.