期刊
JOURNAL OF POLYMER SCIENCE
卷 59, 期 21, 页码 2537-2544出版社
WILEY
DOI: 10.1002/pol.20210417
关键词
mechanophore; naphthopyran; Polymer mechanochemistry
资金
- California Institute of Technology
This study directly compares the reactivity of two isomeric naphthopyrans in solution and solid materials, finding that the 2H-naphthopyran produces a dye with slower reversion rate. By investigating the impact of naphthopyran isomerism on the mechanochromic properties, the study lays the foundation for the development of force-responsive polymers.
Naphthopyrans are molecular switches that produce highly colored merocyanine dyes upon photochemical or mechanochemical activation in polymers. The mechanochromic behavior of these molecular force probes enables the straightforward visualization of stress and/or strain in materials. To date, research on the mechanochemistry of naphthopyran has largely focused on the 3H-naphtho[2,1-b]pyran (3H) scaffold, whereas isomeric 2H-naphtho[1,2-b]pyrans (2H) exhibit complementary properties as suggested from their photochemical reactivity. Here we directly compare the reactivity of two isomeric 2H- and 3H-naphthopyran mechanophores in solution-phase ultrasonication experiments and in crosslinked polydimethylsiloxane elastomers subjected to uniaxial tensile deformation. The prototypical 3H-naphthopyran mechanophore produces a yellow merocyanine dye that reverts quickly, while the 2H-naphthopyran mechanophore generates a red merocyanine dye that reverts significantly slower. The trends in absorption and reversion measured in solution are also reflected in solid polymeric materials activated in tension. Building on recent research into substituent effects, this study identifies naphthopyran isomerism as a simple lever for modulating the mechanochromic properties of the naphthopyran mechanophore used in the development of force-responsive polymers.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据