TAILORING BRANCHING FOR POLY (ARYLENE ETHER)S VIA REACTIVITY RATIO CONTROLLED POLYMERIZATIONS
Abstract (Summary)The ability to control physical and mechanical properties of polymer systems has become an important aspect of polymer science. In order to tailor the branching in polymer systems, an understanding into the reactivity of the electrophilic sites in the monomer is important. Kinetic methods have been explored in order to determine the reactivity of monomers in preparing poly(arylene ether)s and to predict the degree of branching that will occur in a polymer of this kind. The reactivity of AB2 sulfones and phosphine oxides was explored, along with the reactivity of ABB’B’’ sulfones. NMR spectroscopy was used as a probe into the reactivity of the electrophilic sites in the above mentioned systems. Both 13C and 19F NMR spectroscopy were used to analyze model compounds, in order to study the relative reactivity of electrophilic sites in a certain monomer of interest. While NMR spectroscopy is an efficient tool in analyzing the reactivity of the electrophilic sites in a monomer, it is only a guide. A better guide into reactivity would be to actually determine the reactivity, or to calculate the activation energy of the electrophilic site, Ea, via kinetic methods. Once determining the Ea of the electrophilic sites in the monomer, the reactivity of these monomers will aid in determining the branching that will occur in these monomer systems. Once branched polymers have been constructed, the endgroups of these polymers can then be modified for specific applications.
School:Wright State University
School Location:USA - Ohio
Source Type:Master's Thesis
Date of Publication:01/01/2007