Synthesizing new bio-inspired, siloxane-containing materials: an investigation into renewable silicone materials via the application of physical self-healing processes

Abstract

This thesis describes the creation of bio-inspired, silicone-based materials and their properties. The work can be divided into four areas of interest:

The synthesis of thymine-containing silicone polymers (TCSPs). The hydrosilylation reaction was utilized to functionalize silicones with thymine, making both backbone and telechelic TCSPs. A majority of these materials were found to be solid elastomers that, at elevated temperatures (~110oC), turned liquid and were able to be reshaped. The materials then solidified after 5 minutes at room temperature, having been completely recycled. In order to try and improve the properties (mainly flexibility) of these materials, both backbone and telechelic TCSPs were mixed together. However, the resulting products were found to be more brittle than the parent materials. The synthesis of adenine-containing silicone polymers (ACSPs). In this section, several different methodologies were followed in an attempt to make adenine-functionalized silicone materials. It was discovered that the same hydrosilylation approach followed in the construction of TCSPs was not possible with adenine. The feasibility of several coupling methods between silicones and adenine were investigated. The synthesis of thymidine-modified silicone materials. The target material in this work was designed to more closely mimic the overall structure of DNA by incorporating a deoxyribose sugar component, and short-chain silicones as a replacement for the phosphate portion of the DNA backbone. Synthesis of a hydrosilylation precursor, as well as the generation of a model compound and polymer system, were demonstrated. Development of amino-acid modified silicones. The Ireland-Claisen rearrangement was employed in the synthesis of -allyl alanine, which was then be protected and reacted with tetramethyldisiloxane to yield an amino acid with a silicone sidechain. Future prospects for this platform technology will be discussed.