(274a) Surface Grafting and Reactive Modification of Azlactone-Based Polymer Brushes
Reactive modification of polymer thin films provides a useful route to confer new properties to the underlying material, with the range and strength of interactions across the interface dictated by the display of functional groups along the surface. Layers of end-tethered polymer chains, or polymer brushes, were created by grafting chains of poly(4,4-dimethyl-2-vinylazlactone) (pVDMA) onto silicon substrates and in situ functionalization studied through the use of ellipsometry and neutron reflectivity measurements as a function of parameters that set brush structure. The results indicate that the grafting density of chains and size of the functionalizing agent play major roles in governing the extent of functionalization, and with all but the smallest functionalizing agents, reactive modification is incomplete. In addition to developing an average view of the in situ functionalization, the sensitivity of neutron scattering methods to isotopic substitution (of D for H) provides insight into the location of functional groups installed within the pVDMA brush by reactive modification. In total, these studies provide perspectives on the relationship between extent of reaction, display of functional motifs, and properties of the interfacial layer.