Photo-inactive divinyl spiropyran mechanophore cross-linker for real-time stress sensing
Photo-inactive divinyl spiropyran mechanophore cross-linker for real-time stress sensing
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DOI：
10.1016/j.polymer.2016.07.057
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发表时间：
2016-09-02
期刊：
影响因子：
4.6
通讯作者：
Zhu, Shiping
中科院分区：
文献类型：
--
作者：
Li, Meng;Zhang, Qi;Zhu, Shiping
本文研究了一种新型的螺吡喃机械载体交联剂（1 ′-（2-（甲基丙烯酰氧基）乙基）-3 ′，3 ′-二甲基螺[色烯-2，2 ′-吲哚啉]-6-基）甲基丙烯酸甲酯（MA-SP3-MA）在聚丙烯酸甲酯（PMA）中的机械活化作用。与其他SP相比，SP3机械基团具有两个独特的特征。首先，薄膜对机械力表现出良好的敏感性，但对UV照射不敏感。第二，PMA膜弛豫后的汞（MC）到SP的回复非常快。此外，机械活化可以重复三次，但由于过度应变的聚合物链的损坏而导致峰颜色减小。我们还观察到，增加SP含量导致更硬和更刚性的弹性体以及更早的SP到MC的激活点的阈值应变，但对SP激活的阈值应力几乎没有影响。这项工作为聚合物材料的机械载体设计提供了灵感，以拓宽机械载体的潜在应用范围。(C)2016爱思唯尔有限公司版权所有。
In this work, we study the mechanical activation of a new type of spiropyran mechanophore cross-linker, (1'-(2-(methacryloyloxy)ethyl)-3',3'-dimethylspiro[chromene-2,2'-indolin]-6-yl)methyl methacrylate (MA-SP3-MA) in poly methyl acrylate (PMA), prepared via free radical polymerization. Compared with other SPs, SP3 mechanophore shows two unique features. First, the films exhibit good sensitivity towards mechanical force but not to UV irradiation. Second, the merocyanine (MC)-to-SP reversion in PMA films after relaxation was very fast. Further, the mechanical activation can be repeated for three times but with diminishing of peak color, caused by the damage of overstrained polymer chains. We also observe that increasing SP content leads to stiffer and more rigid elastomer as well as earlier threshold strain for activation point of SP to MC but has little effect on threshold stress for SP activation. This work offers inspirations towards mechanophore design for polymeric materials to broaden the scope of potential applications of mechanophores. (C) 2016 Elsevier Ltd. All rights reserved.