High strain‐rate response of spiropyran mechanophores in PMMA. Issue 20 (18th August 2014)

• Record Type: Journal Article
• Authors: Hemmer, James R.; Smith, Patrick D.; van Horn, Matt; Alnemrat, Sufian; Mason, Brian P.; de Alaniz, Javier Read; Osswald, Sebastian; Hooper, Joseph P.
• Is Part Of: Journal of polymer science. Volume 52:Issue 20(2014:Oct. 15)
• Page Start: 1347
• Page End: 1356
• Publication Date: 2014-08-18
• Subjects: 547
• DOI: 10.1002/polb.23569
• Languages: English
• ISSNs: 0887-6266

Abstract

<abstract abstract-type="main"> <title>ABSTRACT</title> <p>We report the high strain‐rate response of a spiropyran (SP) mechanophore in poly(methylmethacrylate). Previous work on this system has demonstrated a reversible bond scission in the SP under local tensile force, converting it to a fluorescent merocyanine form. A Hopkinson bar was used to apply fast compressive loads at rates from 10² to 10⁴ s⁻¹, resulting in significant activation of the SP near fracture surfaces. However, comparison with a similar thermochromic SP reveals that much of the observed activation likely arises from thermal effects during high‐rate fracture. These results show the importance of a thermally active control system in distinguishing mechanochromic response during high‐rate loading. Microscale fluorescence mapping of the fracture surfaces using a confocal Raman microspectrometer suggests that some distinct mechanical activation may be occurring in craze‐like regions during fibril rupture. The thermal response of the SP is useful in its own right for characterizing plastic heating regions during dynamic fracture. Published 2014. J. Polym. Sci., Part B: Polym. Phys. <bold>2014</bold>, <italic>52</italic>, 1347–1356</p> </abstract>