Functional Polymer Surfaces

Virginia Commonwealth University, Richmond VA

Investigators

Abstract

TECHNICAL SUMMARY: This research is aimed at generating polymer surfaces with novel or improved function by an approach that insures compositional economy and facile, conventional processing. Desired surface functions will be generated via a modifier that spontaneously concentrates at the surface based on synthetic approaches to be used in this project. The focus will be modification of soft polymer surfaces, including polyurethanes and silicones. Such research is challenging because of high nanoscale mobility for near-surface polymer chains that can drive phase separation and negate surface modification. Recently, a new hybrid bottlebrush-nanoglass (BB-NG) strategy has resulted in restriction of near-surface modifier chain mobility. Thus, BB-NG surface modification will be a primary focus of future research. Preliminary results with a modified polyurethane system indicate stable surface-concentrated quaternary charge. Zeta potentials are being investigated to test the limits of charge stability. Another result suggests broad applicability for BB-NG modifiers. BB-NG modification for a hybrid fluorooxetane system led to an unexpected self-layered soft surface/ tough bulk. This unusual compositional stratification will be the subject of further research, as initial results show very low ice adhesion. Potential applications include coatings for wind turbines and power lines. Finally, new ways to introduce surface function into silicones will be explored that also involve balancing desired surface function and near-surface phase separation. NON-TECHNICAL SUMMARY: This research is aimed at introducing special surface properties into conventional polymers that are commonly encountered in coated or molded objects. For example, incorporating a small amount of surface modifier is leading to coatings with combinations of desirable properties such as oil and water resistance as well as easy release of ice. Such coatings may have applications for coating power lines, airplane wings and wind turbine blades. Broader impacts of this research will include interdisciplinary training and curriculum development. Another impact is the participation of underrepresented minorities in the research program by collaboration with Virginia State University. On a national level, support for this research will facilitate K-12 leadership activities that bring new knowledge to high school and secondary school teachers who, in turn, will incorporate this knowledge into classroom science instruction. Internationally, collaborative activities with Japan and Italy have led to productive student exchanges and will continue through this project.