Functional polymers via ring-opening metathesis polymerization

The first chapter describes the use of ring-opening metathesis polymerization (ROMP) for the synthesis of poly(sulfones) from functionalized 7-oxanorbomenes. Tungsten and molybdenum alkylidenes as well as ruthenium salts were used to generate polymers with varied backbone geometric- and stereo-isomerism. These poly(sulfones) exhibit clean mass loss under both oxidative and inert atmospheres. Thermal gravimetric analysis was used to investigate these poly(sulfones), as well as other 7-oxanorbornene polymers. Comparison of ether, amide and acid derivitized polymers indicates that clean thermolysis is observed when the polymer contains the following features: an oxygen of the tetrahydrofuran ring, a second ring fused to the tetrahydrofuran ring, a high proportion of trans-to-cis bonds, an atactic backbone, and the sulfone group. Product studies indicate that the mechanism of decomposition under an argon atmosphere involves initial loss of sulfur dioxide. Based on comparison of thermal analysis data of olefinic and saturated polymers, oxidative attack at the olefin backbone is postulated as the first step in degradation under ambient atmosphere. In the second chapter of this thesis, the use of living poly(exodicyclopentadiene) and living poly(norbornene) in reactions with a telechelic dialdehyde to form triblock co-polymers by coupling of reactive end groups is detailed. A reagent-specific degradation reaction prevented the isolation of triblock co-polymers from excess homopolymer, although gel-permeation chromatographs indicate that the coupling takes place with good efficiency. The successful use of poly(styrene-co-vinylbenzaldehyde) as a scavenging reagent for ROMP polymers is also reported. Several small projects are discussed in the third chapter. The most important topic is the ionophoric behavior of ROMP poly( ethers). Monomers and polymers containing amines, thiophenes and methanesulfonyl groups are also discussed. The methanesulfonylderivitized ROMP polymer exhibits clean, uncatalyzed, elimination of methanesulfonic acid at 220 °C, which has implications for precursor polymers currently under study.