Environmental effects on mechanochemical activation of spiropyran in linear PMMA

Brett A. Beiermann, Douglas A. Davis, Sharlotte L.B. Kramer, Jeffrey S. Moore, Nancy R. Sottos, Scott R. White

Research output: Contribution to journalArticlepeer-review

Abstract

Mechanophore-linked linear poly(methyl methacrylate) (PMMA) was synthesized using bisfunctionalized spiropyran (SP) as an atom transfer radical polymerization initiator. The resulting polymer had a Tg of 127 °C and molecular weight greater than 250 kDa. SP-cleavage experiments confirmed the incorporation of SP molecules approximately into the center of the polymer chain. Force-induced reaction of the SP species into a colored, fluorescent merocyanine (MC) form was investigated over a range of environmental conditions by monitoring color change or full field fluorescence during tensile loading. Activation of this glassy polymer was observed in a temperature range of 90-105 °C. At higher temperatures, approaching Tg, deformation was dominated by viscous flow at very low applied stress with no activation. At lower temperatures, brittle failure preceded activation unless the polymer was plasticized by exposure to methanol. Mechanically induced activation of SP in plasticized PMMA at room temperature (22 °C) was achieved at a critical strain (ca. 10%) substantially below that required in previous systems.

Original languageEnglish (US)
Pages (from-to)8443-8447
Number of pages5
JournalJournal of Materials Chemistry
Volume21
Issue number23
DOIs
StatePublished - Jun 21 2011

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Chemistry

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