| dc.description.abstract | Carbohydrates are fundamental building blocks for natural polymers; their bioavailability, chemical functionality, and stereochemical diversity make them attractive starting materials for the development of new synthetic polymers. This dissertation describes the development of polycarbonate materials from derivatives of one such carbohydrate, ᴅ-glucopyranoside. Several novel monofunctional and multifunctional monomers were synthesized to produce linear and branched/crosslinked polymers. The regiochemical and stereochemical sophistication inherent to carbohydrates was harnessed in each project to study the effects on chemical reactivity of the monomers and on physicochemical properties of the resulting polymers.
A library of linear poly(glucose carbonate)s (PGCs) was synthesized from a single monomer, methyl 4,6-O-benzylidene-2,3-O-carbonyl-α-ᴅ-glucopyranoside (MBGC), via ring-opening polymerization (ROP) followed by post-polymerization reactions, to determine the effect of repeat unit structure and molar mass on polymer properties. Beyond the production of homopolymers, MBGC was further employed to afford amphiphilic copolymers and block copolymers via ROP with a small molecule initiator and a macroinitiator, respectively. Within these different polymeric systems, a wide range of thermal decomposition temperatures (221-339 °C), glass transition temperatures (-48-222 °C, Tvg), and water contact angles (38-128°) were achieved. Further, assembly of the amphiphilic copolymers and block copolymers under aqueous conditions revealed interesting morphological differences as a function of composition.
In efforts to produce multifunctional monomers for branched/crosslinked polymeric materials, a difunctional cyclic carbonate monomer methyl 2,3:4,6-di-O-carbonyl-α-ᴅ-glucopyranoside (MGDC) for ROP, as well as a synthetic methodology for multifunctional alkene-containing monomers for thiolene photopolymerization were developed. ROP of MGDC was studied by varying the conditions to produce branched and linear homopolymers. In addition to homopolymerization, MGDC was also used as a comonomer to create branched/crosslinked PGCs. The multifunctional alkene-containing monomers were copolymerized with a variety of multifunctional thiols to produce networks with a range of thermal and physical properties depending on the comonomer composition, with Tvgs from -17 to 58 °C and storage moduli from 0.4 to 30 MPa.
This dissertation focuses on the development of monomers that will allow for the straightforward synthesis of glucose-based polycarbonates. Multiple monomers and polymerization techniques were utilized in this work to produce polymers with varied architectures. Throughout, the effect of different functionalities and regiochemistries of the monomers were correlated to the properties of the resultant polymers. Overall these highly tunable, glucose-based degradable polymeric platforms hold great promise for the sustainable production of advanced engineering materials, biomaterials, and composites for implementation in a diverse range of applications, from medicine to electronics, and many others. | en |
