The fabrication of functional hydrogels with tuned thermoresponsivity is a major challenge. To meet this challenge we copolymerize N-isopropylacrylamide (NIPAm) with N-vinylformamide (NVF) in different ratios with the formamide group being subsequently selectively hydrolyzed to the corresponding amine (VAm). The copolymers are crosslinked with phenylcarbonate telechelic glycol. The influence of the NIPAm : VAm ratio on the thermoresponsitiviy is investigated in terms of absorbance, rheology, NMR spectroscopy, relaxometry, and diffusometry. Phase transition temperatures, change in the entropy of the polymer–water system, and width of the transition in the process of coil-to-globule and swollen-to-collapsed network transitions were evaluated by a two state model and Boltzmann sigmoidal function.

中文翻译：

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聚乙烯醇-共-N-异丙基丙烯酰胺共聚物线性聚合物和具有可调热响应性的水凝胶。

具有调节的热响应性的功能性水凝胶的制备是主要挑战。为了应对这一挑战，我们将N-异丙基丙烯酰胺（NIPAm）与N-乙烯基甲酰胺（NVF）的比例不同，随后甲酰胺基团选择性水解为相应的胺（VAm）。该共聚物与碳酸苯酯远螯二醇交联。从吸光度，流变学，NMR光谱，弛豫法和扩散法等方面研究了NIPAm：VAm比对热响应性的影响。通过两种状态模型和玻尔兹曼S型曲线函数评估了相变温度，聚合物-水系统的熵变以及线圈到小球以及溶胀到塌陷的网络过渡过程中的过渡宽度。