Fluorine-containing dendritic and hyperbranched macromolecules are being designed and synthesized specifically to evaluate: 1) their micromechanical properties; 2) the reactivities of the chain end groups, and; 3) the location and mobility of the chain ends. Initially, pentafluorophenyl groups, which have been shown by atomic force microscopy to decrease the cohesive and adhesive forces of the materials in the solid-state, terminate the chain ends of the structures. The fluorine atom in the para-position of the pentafluorophenyl group is susceptible to nucleophilic attack, thus allowing for modifications in the structures through the introduction of new functionalities at the chain ends of the dendritic fluoropolymers. This displacement reaction is being employed in the study of the reactivity of the dendrimers and hyperbranched macromolecules. A hyperbranched analog of bisphenol A poly(carbonate) is also being prepared and studied. The hyperbranched poly(carbonate) is expected to be a processable and tough engineering material, that also allows for the simple introduction of functional groups to tailor the properties of the material to specific applications. Matrix assisted laser desorption ionization (MALDI) mass spectrometry is used for characterization of the polymer molecular weight since the polymer is so highly branched that gel permeation chromatography techniques are not applicable.
Showing the most recent 10 out of 696 publications
