Tailoring Lifetimes and Properties of Carbodiimide-Fueled Covalently Cross-linked Polymer Networks
Tailoring Lifetimes and Properties of Carbodiimide-Fueled Covalently Cross-linked Polymer Networks
复制标题
DOI：
10.1021/acs.macromol.1c01586
复制
发表时间：
2021-10-26
期刊：
影响因子：
5.5
通讯作者：
Konkolewicz, Dominik
中科院分区：
文献类型：
--
作者：
Dodo, Obed J.;Petit, Leilah;Konkolewicz, Dominik
研究了通过化学燃料对聚合物链进行瞬时交联而获得的非平衡聚合物水凝胶的机械性能。用碳二亚胺处理具有侧链羧酸的水性聚合物，得到酸酐交联的凝胶。酸酐自发水解回聚合物溶液，并且该循环可以重复多次。采用振荡流变学来研究温度、燃料浓度、链长和聚合物组成对聚合物材料的储能模量和损耗模量以及聚合物解交联所需时间的影响。无论使用什么温度，在恒定的碳二亚胺浓度下，脱胶时间对实验温度的影响比峰值储能模量更敏感。解交联时间随着温度的升高而缩短。随着碳二亚胺浓度降低，模量和解交联时间减少。在研究的材料范围内，发现与燃料浓度和温度相比，聚合物结构对凝胶网络的瞬态特性的影响相对较小。这些发现有助于可调按需网络和凝胶的设计。
The mechanical properties of nonequilibrium polymer hydrogels obtained from the transient cross-linking of polymer chains by a chemical fuel were investigated. Aqueous polymers featuring pendant carboxylic acids were treated with a carbodiimide to give anhydride-cross-linked gels. The anhydrides spontaneously hydrolyze back to the polymer solution, and the cycle can be repeated multiple times. Oscillatory rheology was employed to study the effects of temperature, fuel concentration, chain length, and polymer composition on the storage and loss moduli of the polymeric materials as well as the time taken for the polymers to undergo decross-linking. Regardless of the temperature used, at constant carbodiimide concentration, degelation times are more sensitive to experimental temperature than are the peak storage moduli. Decross-linking times decrease with increasing temperature. As carbodiimide concentration decreases, there is a decrease in moduli and decross-linking times. Within the scope of materials studied, the polymer structure was found to have a relatively small impact on the transient properties of gel networks compared to the fuel concentration and temperature. These findings facilitate the design of tunable on-demand networks and gels.