464850 Simultaneous Scission and Gelation Reactions in Photocrosslinkable Polymers

Thursday, November 17, 2016: 2:15 PM
Golden Gate 2 (Hilton San Francisco Union Square)
Dustin Janes, Center for Devices and Radiological Health, FDA, Silver Spring, MD, Michael J. Maher, Department of Chemistry, University of Texas, Austin, TX, Gregory Carroll, Sunstar Engineering Americas, Springboro, OH and Christopher J. Ellison, Dept. of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN

Polymers used in medical devices, lithographic patterning, and other applications are often exposed to ultraviolet, e-beam, or gamma irradiation to obtain a sterile and/or crosslinked polymer. Since these stimuli can produce free radical intermediates on the polymer backbone, simultaneous gelation and scission reactions will occur. These reaction rates underlie the resulting mechanical properties, % oxidation, and % leachables, but in practice these reactions are challenging to directly quantify. To establish a simple approach for extracting stoichiometric likelihoods of scission or gelation reactions resulting from irradiation, we have adapted the Miller-Macosko statistical model to account for these effects. The simple, closed form expressions that result provide a means to quantitatively analyze sol fraction vs. dose data and gain mechanistic insight into these reactions. Here we will describe our approach in detail and apply it a model photopolymer, poly(styrene sulfonyl azide-alt-maleic anhydride).

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See more of this Session: Polymer Networks and Gels
See more of this Group/Topical: Materials Engineering and Sciences Division