Degradation Behavior of Polymer Gels Caused by Nonspecific Cleavages of Network Strands
Degradation Behavior of Polymer Gels Caused by Nonspecific Cleavages of Network Strands
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DOI：
10.1021/cm502480f
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发表时间：
2014-09-23
影响因子：
8.6
通讯作者：
Sakai, Takamasa
中科院分区：
文献类型：
--
作者：
Li, Xiang;Kondo, Shinji;Sakai, Takamasa
本文系统地研究了网络链非特异性断裂对水凝胶降解行为的影响。凝胶试样的体积随着降解过程的进行而增大，并表现出温度依赖性和网络链长度依赖性。我们的新模型基于网络链上化学键的准一级断裂动力学，与降解行为吻合得很好。估计的网络链的表观降解速率常数是其长度的线性函数，对应于网络链长度依赖于凝胶试样的宏观体积变化。网络上的化学键（醚键和酰胺键）的降解速率常数符合过渡态理论。计算得到的各键的活化焓均在前人研究的数值范围内，表明了模型的有效性。
We report a systematical study of degradation behavior of hydrogels that suffer from the nonspecific cleavage on the network strands. The volume of the gel specimens increased with the degradation progress, and denoted the temperature dependence and the network strand length dependence. Our new model based on the pseudo-first-order cleavage kinetics of the chemical bonds on the network strands well agreed with the degradation behavior. The estimated apparent degradation rate constants of the network strands were linear function of their length, corresponding to the network strand length dependence on the macroscopic volume change of the gel specimens. The estimated degradation rate constants of the chemical bonds on the network stand, which were ether and amide bond, obeyed the transition state theory. The calculated activation enthalpy of each bond was in the range of the values in previous studies, indicating the validity of our modeling.