Synthesis, Characterization and Modification of Hyperbranched Ultrathin Grafts on Polymer Films, Fibers and Powders

9977911 Bergbreiter这个项目中的化学将导致使用超支化接枝对聚合物表面进行改性的新方法。缩合聚合化学将用于将共聚物、树枝状大分子和功能胶体连接到含有羧酸的底物上。完全通过碳-碳键连接的超支化移植物也将使用Heck和Wittig化学的组合来制备。这些超支化接枝将被制备在聚烯烃薄膜、粉末、胶体颗粒和纤维上。由此产生的移植物将被设计成对酸碱度和温度做出反应。由超支化接枝形成的薄膜界面的进一步修饰将通过共价和离子修饰化学来完成。通过“活性”径向聚合进行的共价改性将与超支化接枝上的“简单”共价接枝进行比较。还将研究用聚电解质树枝状大分子、生物聚合物和嵌段共聚物对超支化接枝的离子修饰，并与在含有单分子官能团的中性底物上进行类似的离子组装工艺进行比较。物理和光谱研究将探索这些移植物的覆盖范围、它们对各种外部刺激的反应性以及它们的反应性。这类研究将主要使用荧光、紫外可见、ESR和XPS光谱。这些研究的结果将改进一般的合成路线，在不同的衬底上制备功能薄膜。这种表面修饰化学将导致新的方法来改善常用聚合物的表面性质。这种表面性能的改善将导致材料具有更好的印刷性、附着力和生物兼容性--这些性能非常重要，因为现有材料正在进行改性，以便在生物技术和材料科学中发挥更大的作用。

9977911BergbreiterThe chemistry in this project will lead to new methods for polymer surface modification using hyperbranched grafts. Condensation polymerization chemistry will be used to attach copolymers, dendrimers and functional colloids to carboxylic acid containing substrates. Hyperbranched grafts completely attached via carbon-carbon bonds will also be prepared using a combination of Heck and Wittig chemistry. These hyberbranched grafts will be prepared on polyolefin films, powders, colloidal particles and fibers. The resulting grafts will be designed to be responsive to pH and temperature. Further modification of the thin film interfaces formed by hyperbranched grafting will be accomplished by covalent and ionic modification chemistry. Covalent modification by "living" radial polymerization will be compared to "simple" covalent grafting on hyperbranched grafts. Ionic modification of hyperbranched grafts with polyelectolyte dendrimers, biological polymers and block copolymers will also be studied and compared with similar ionic assembly processes on neutral substrates containing monolayers of functional groups. Physical and spectroscopic studies will probe the extent of coverage of these grafts, their responsiveness to various external stimuli and their reactivity. Such studies will primarily use fluorescence, UV-visible, ESR and XPS spectroscopy. The result of these studies will be improved general synthetic routes to functional thin films on various substrates. This surface modification chemistry will lead to new methods to improve the surface properties of commonly used polymers. Such improved surface properties should lead to materials with better printability, adhesion and biocompatibility - properties that are important as existing materials are modified to be of increased utility in biotechnology and materials science.