Synthesis of polyelectrolytes for biomedical applications via ring opening metathesis polymerization of 7-oxanorbornene derivatives and development of a polymer laboratory course for undergraduate students.

Abstract

A 7-oxanorbornene derivative, 2-exo-methoxymethyl-3-exo-2 (2-(2-trimethylammoniumethoxy)ethoxy) ethoxymethyl-7-oxabicyclo (2.2.1) hept-5-ene chloride (1) was designed and synthesized as a monomer for biomedical applications. To arrive at 1, a total of six synthetic steps were required of which the last two steps were original. Numerous precursors of this compound were synthesized and discussed. Model compounds were chosen and polymerized under ring opening metathesis polymerization (ROMP) conditions. Copolymers were made with a neutral monomer, exo-5,6-dimethoxymethyl-7-oxabicyclo (2.2.1) hept-2-ene (4). The polymers and copolymers had molecular weights ranging from {dollar}2.63\times10\sp5{dollar} to {dollar}3.71\times10\sp6{dollar} with narrow polydispersity. Thermal analysis as measured by Differential scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) showed the polymers to have T{dollar}\rm\sb{lcub}d{rcub}{dollar} (decomposition temperature) {dollar}>{dollar} 274{dollar}\sp\circ{dollar}C and some had a T{dollar}\rm\sb{lcub}g{rcub}{dollar} (glass transition temperature) around 190{dollar}\sp\circ{dollar}C. The target polymer, poly-1, made for the first time, had a thermal stability comparable to the other polymers.

Since the Doctor of Arts degree has a fundamental pedagogy component, a section entitled "Development of a Polymer Laboratory Course for Undergraduate Students" was discussed in Part II. Specifically, the role of the Teaching Assistant was described, and a qualitative analysis of the success of the course was made.