I have examined three different topological forms of a material modifier. The modifier is silicone and the three topological forms are cyclic, linear tethers and networked siloxane bonds in the form of a nanoparticulate. Often silicones, or siloxanes, are added to a material because of its unique properties that are related to its inorganic or inorganic-organic hybrid character. This dissertation addresses either the synthesis of silicones for material modification or the effect of the adding silicones to a variety of substrates and polymeric systems. Chapters 2 and 3 present research focused on the first topological form, cyclic PDMS. The synthesis of cyclic polymers is very important to the synthesis and subsequent characterization of cyclic containing multi-component materials. Cyclic PDMS is formed via ring-chain depolymerization and bimolecular coupling and the unique issues associated with the formation, purification and analysis of cyclic polymer topologies. The goal of the work described in these chapters was to find a straightforward high-yield route to form large cycles of PDMS in a relatively high purity. Chapter 4 focuses on the modification of the next topological form, linear polymers as tethers for surface modification and presents a novel concept for surface-modifying compounds; the incorporation of an ionic-reactive functionality into PDMS is presented. The idea being its ionic character will increase affinity for the surface, surface coverage and levelness, while the subsequent reactive fixation will permanently modify the surface to improve retention and fastness. The use of such chemistry has not been applied for surface modification protocols. Chapters 5, 6 and 7 discuss the characterization of systems with the third topological form incorporated. They include differences in the viscoelastic behavior of PVAc/silica nanocomposites and the neat PVAc matrix, relating those differences to polymer dynamics and structure as determined by several solid-state NMR experiments. The latter two chapters pertain to PVAc/silica nanocomposites with PDMS surface treatments. Specifically, evaluating how polymer dynamics and structure changes particularly at the interfaceinterphase with various PDMS surface treatments having different topologies at the surface.

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This work addresses the distribution of N-methylolacrylamide (NMA) units in crosslinking poly(vinyl acetate) (PVAc) adhesives. In this case, distribution refers to the three potential locations of polymerized NMA units in a latex: the water-phase, the surface of polymer particles, and the core of the polymer particles. The objective is to identify the distribution of NMA in three latices and to determine whether NMA distribution correlates with durability related performance. NMA distribution was studied via a series of variable temperature solution NMR experiments, while the durability-related performance was studied via mode I fracture mechanics tests. Studying the distribution of NMA required the use of isotopically labeled NMA. Both 15N-NMA and 13C, 15N-NMA were synthesized. Three NMA/vinyl acetate (VAc) latices were prepared. The NMA feed strategy was varied during each of the three emulsion copolymerizations. Latex characterization methods including differential scanning calorimetry (DSC), rheometry, particle size analysis, and scanning electron microscopy (SEM) were used to study the three latices. The solution NMR method to identify NMA distribution was performed on untreated latices and on washed latices. Washing techniques included membrane dialysis and centrifugation. Results revealed that the three latices had different NMA distributions, and that the distributions were related to the expected differences in microstructure. Latex 3 had ~ 80% core-NMA, while Latex 2 had ~ 80% surface-NMA. Latex 1 had a high proportion of surface-NMA (~60%), but also had the highest proportion of water-phase NMA (~ 20%). This high proportion of water-phase NMA could be responsible for the unique morphology Latex 1 exhibited in SEM studies. Mode I opening fracture mechanics studies were used to study adhesive performance. Specimens were analyzed after exposure to accelerated aging treatments. Latex 2 and Latex 3 exhibited very similar results, despite having very different NMA distributions. All three latices showed good durability related performance. In Latex 2 and Latex 3, the critical strain energy release rates (Gc) after accelerated aging treatments were statistically the same as the Gc of the control specimens. The most interesting finding was that the Latex 1 Gc values were significantly higher after accelerated aging. Latex 1 also had the highest proportion of water-phase NMA. Bondline images and SEM micrographs both indicated that the integrity of Latex 1 was least affected by the accelerated aging treatments. / Ph. D.