(122c) Transient Polymers: Building Short-Lived Structures

Polymer materials are normally created with the idea in mind that they will endure a significant period of time with unchanging physical properties. Increasingly polymers that have short life spans are needed in a variety of applications in which the polymer retains its desired physical properties until a specific triggering event is encountered. Well known examples include photoresists used in microelectronics manufacture and more recently applications involving biomedical diagnostics, distributed environmental sensors, or multifunctional devices where short-term use is desirable and recovery is difficult. In this presentation we explore the use of heat and acidity to control the rapid breakdown of a polymer side group or back bone. These critical groups are largely built from carbonate and tertiary ester groups known to undergo acid and thermal cleavage. Several examples will be described including: (i) new photoresists with unusual solubility characteristics that are well suited to processing organic or polymer based electronics; (ii) fugitive adhesives that undergo rapid heat induced breakdown and (iii) transient polymers for device substrate fabrication whose disappearance is triggered by heat and pH.