emulsion polymerization using A4F-MALS technique

High levels of acrylate in poly(methyl methacrylate), or PMMA, lead to 

formation of highly branched, compact macromolecules with ultra-high 

molar masses. The interaction of these short branches with column packing 

pores leads to abnormal (non-monotonic) elution in size-exclusion 

chromatography, resulting in poor separation and characterization by any 

means including viscometry or light scattering. In addition, these large 

polymers are subject to degradation by shear forces in the SEC column. 

Stepan Podzimek and co-authors show that separation by organic AF4 in 

tetrahydrofuran solvent overcomes the problems associated with SEC for 

PMMA, and permits accurate characterization of molar mass, size, 

conformation and branching ratio.

Podzimek, S.; Machotova, J.; Snuparek, J.; Vecera, M.; Prokupek, L. 

Journal of Applied Polymer Science 2014, 131, 40995. doi:10.1002/app.40995