Modifiable Poly(arylene ether)s and Hyperbranched Poly(esters)

by Werry, Brian Scott

Two different polymer systems have been studied in regards to their potential for functionalization to introduce new characteristics to the polymer. The first polymer system is a poly(arylene ether) with a truly pendant sulfone group from the monomer 3,5-difluorodiphenylsulfone. The work entails incorporating a bromine moiety onto the monomer for the versatile ability to bring in functional groups prior to or post the polymerization. The introduction of bromine onto the pendant ring had the best results from electrophilic bromine addition using N-bromosuccinimide in a mixture of sulfuric acid and acetic acid (80:20) yielding 76% of the desired material. Incorporation of the bromine moiety did not interfere with the nucleophilic aromatic substitution reaction utilized in the polymerization and modification was shown to proceed smoothly both prior and post polymerization. The second project involved the study and production of a poly(ester) hyperbranched system from glycerol and fumaric acid. These hyperbranched polymers were prepared using an A2 + B3 approach in a bulk synthesis. The study involves varying the molar ratio of A2 to B3 and temperature to control the polymerization and avoid gelation while pushing the polymerization to larger molecular weights. The two monomers bring the characteristic of biocompatibility with them into the polymer. In addition, the fumaric acid monomer unit brings an alkene bond available for modification. Average molecular weights achieved were around 5,000 daltons. Obtained PDI values were as low as 4.6, and DB values ranged from 0.26 to 0.38. Analysis on new compounds and polymers was done by NMR spectroscopy, GC/MS, and size exclusion chromatography where applicable.