Scott Grayson

There have been a few studies of the dendrimer and its architectural hyperbranched and linear equivalents.  However, these only have one species for all three architectures, and the dispersity of the hyperbranched and linear were between 1.8-3.9.  The majority of these dendrimers and hyperbranched polymers have generally become obsolete, but one of the few that has remained important is the bis-MPA family.  The group of Anders Hult first published the hyperbranched polymer in 1994 and commercialized this as Boltorn, one of the best toughening agents for the crosslinked polyurethanes.  Next, this same group determined that they can also synthesis the analogous dendrimers and this has been completed to the eighth generation with a 1.0 dispersity.  However, only recently has anyone determine the equivalent linear polymer from bis-MPA, from polymerization of the monomer, 3-(benzoyloxy)-2-(bromomethyl)-2-methylpropanoic acid.  One of the advantages is that this is a chain growth polymerization, therefore the highest dispersity is below 1.2 for all of the linear polymers.  Our group has also comprised the hyperbranched and linear polymers with the same benzoyl groups.  The generation one through four dendrimers have equivalents (with 15% real molecular weight) of the hyperbranched and linear polymers. The differential scanning calorimetry, the thermogravimetric analysis, as well as the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and gel permeation chromatography with refractive index, viscometry, and multi-angle light scattering have been determined and compared for each one of these.

Scott M. Grayson complete his PhD in Chemistry from the University of California, Berkeley and carried out his post-doctoral studies at the University of Texas. He was appointed as a professor at the Department of Chemistry at Tulane University in New Orleans, Louisiana, USA in 2005.  He now holds the Joseph H. Boyer Professorship of Chemistry at Tulane where he explores the synthesis and applications of well-defined, yet complex macromolecular structures.  His research group has focused on the synthesis of amphiphilic and cyclic polymers for applications including transdermal drug delivery and gene therapies, but also focuses on new techniques for polymer characterization.  His most recent work describes the utilization of a relatively common monomer, bis-MPA, and describes the first work of the linear bis-MPA ester, as well as variations of the dendritic and hyperbranched monomers.

• Time: 11:00 AM
• Location: 206 Furnas Hall