Master of Engineering Science
Chemical and Biochemical Engineering
Dr. Elizabeth Gillies
Linear self-immolative polymers display a potential to address many of the limitations in the control over the degradation process in traditional biodegradable polymers. These materials are unique relative to most degradable polymers, in that they undergo end-to-end depolymerization in response to the cleavage of a stabilizing end-capping agent. Although one of their cited attributes is a dependence of their degradation time on chain length, no conclusive study has been conducted to demonstrate and study this effect. Using a previously reported linear self-immolative backbone derived from alternating 4-hydroxybenzyl alcohol and N,N’-dimethylethylenediamine spacers, this work offers the first conclusive study demonstrating the proportional relationship between chain length and degradation time. This is accomplished using a set of monodisperse oligomers synthesized through a new convergent iterative route and a series of polymers optimized to display varying molecular weights. This work also describes the development and validation of a new linear self-immolative degradation model relating monomer kinetics to polymer degradation and shows its application in explaining oligomeric and polymeric degradation profiles. Collectively, this work provides the first quantitative evidence supporting the mixed pseudo zero- and first-order degradation kinetics of linear self-immolative polymers and proves the utility of chain length as an alternate means to tune the degradation time in linear self-immolative polymers. In the second focus of this thesis, a series of modified linear self-immolative amphiphilic block copolymer designs are proposed and evaluated in an effort to develop functional self-immolative nanoparticles for controlled release applications. Overall, the work presented in this thesis serves to expand the utility of linear self-immolative polymers for biomedical applications by demonstrating the flexibility of such systems through controlled design.
McBride, Ryan A., "Degradation Kinetics and Functional Design of Linear Self-Immolative Polymers" (2013). Electronic Thesis and Dissertation Repository. 1314.