Development of Poly(benzyl ethers) that Undergo Selective, Continuous Depolymerization for Use in Responsive Materials

Open Access
Author:
Olah, Michael G
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
August 06, 2015
Committee Members:
  • Scott T Phillips, Dissertation Advisor
  • Ayusman Sen, Committee Member
  • Alexander Thomas Radosevich, Committee Member
  • Michael Anthony Hickner, Committee Member
Keywords:
  • polymers
  • depolymerization
  • responsive materials
  • self-immolative polymers
  • photoresist
Abstract:
Polymers that can selectively and continuously depolymerize are finding increasing use as responsive materials. Depolymerizable polymers have been employed to create microscale pumps, responsive capsules, small-molecule sensors, and shape-changing plastics. Selective, continuous depolymerization provides rapid and dramatic changes within a material that are difficult to achieve via other methods. The design and synthesis of new depolymerizable polymers, however, is an unmet challenge. Only a handful of polymers have been shown to undergo selective, continuous depolymerization, and fewer still have been demonstrated to respond in the solid state. This dissertation describes a new class of depolymerizable poly(benzyl ethers) synthesized from stabilized quinone methide monomers. Upon application of a chosen stimulus and exposure to basic conditions, the poly(benzyl ethers) undergo an anionic elimination cascade to release their constituent monomers within minutes. These poly(benzyl ethers) remain stable against non-selective degradation from acid, base, or heat while end-capped, and furthermore, can depolymerize rapidly in low polarity solutions, as well as in the solid state. This dissertation also details efforts to create photoresists and responsive bulk materials from these responsive poly(benzyl ethers).