|Wednesday, February 6 Preservation Hall B, 2nd Floor 4:30 pm - 5:00 pm|
|Dr. Timothy McKenna||Novel Technologies and Chemistries for Waterborne Coatings|
Co-Authors: Bernadette Charleux, Elodie Bourgeat Lami, Mureil Lansalot
Key industrial drivers for production of waterborne coatings and binders include the need for ever-improving material properties combined with lowering production and application costs, and further reducing any negative environmental that their production and use might have. In addition the modification of existing formulae to incorporate inorganic (e.g. silicates, metal oxides) or organic (alyds, polyurethanes) charges in the base polymer is of significant importance. Obviously producers have made signficant strides in this direction, but there remains room for further improvement. This paper will present an overview of some of the major contributions our group has made in recent years in related areas of high solids systems, organic-organic and organic-inorganic coatings, and chemistries for macromolecular architectures. One method for produsing advanced hybrids with high solid contents is via the generation and polymerisation of miniemulsions; mechanically generated dispersions of a charge-containing organic phase that can be polymerised via conventional or novel chemistries in existing production facitilities. We have shown this this is feasible on large scales and in continuous plants, for instance by including inexpensive surfactant systems that can significatnly reduce energy costs. In addition we will look at some of the possibilities in terms of incorporating different types of materials in the final product that are facilitated with this technology. The incorporation of inorganic colloids in polymer particles during their synthesis allows us to enhance their properties. Typically their synthesis requires the presence of surfactant molecules for the colloidal stability of the latex. However, there is an increasing interest in removing this type of stabiliser for a number of environmental and quality-related reasons. One possibility for the replacement of conventional stabilisers is the use of cerium oxide nanoparticles (CeO2). We have developed a strategy based on the use of RAFT chemistry, and demonstrated that the incorporation of CeO¬2 nanoparticles in surfactant-free polymer films opens up new opportunities, particularly in the field of anti-UV films with improved mechanical properties. Finally, in addition to conventional free radical processes and chemistries, we have been exploring the use of RAFT and NMP polymerisation methods to investigate the control of morphologies. These methods can be used to make structured micelles, to promote self-assembly of waterborne objects with novel morphologies such as fibres, cylinders of esicles, or even cholesterol-based liquid crystal structures.