Chair of Forest Biomaterials, Faculty of Environment and Natural Resources, University of Freiburg, 79085 Freiburg, Germany.
Freiburg Materials Research Center, University of Freiburg, 79104 Freiburg, Germany.
Molecules. 2020 Jan 7;25(2):243. doi: 10.3390/molecules25020243.
The study of Diels-Alder reactions in materials science is of increasing interest. The main reason for that is the potential thermoreversibility of the reaction. Aiming to predict the behavior of a material modified with maleimido and furyl moieties, H NMR and UV-Vis solution studies of the Diels-Alder reaction between furfuryl alcohol and two -hydroxymaleimides are explored in the present study. Rate constants, activation energy, entropy, and enthalpy of formation were determined from each technique for both reacting systems. and isomers were distinguished in H NMR, and the transition from a kinetic, controlled Diels-Alder reaction to a thermodynamic one could be observed in the temperature range studied. A discussion on the effect of that on the application in a material was performed. The approach selected considers a simplified equilibrium of the Diels-Alder reaction as the kinetic model, allowing materials scientists to evaluate the suitability of using the reacting molecules for the creation of thermoresponsive materials. The proposed approach determines the kinetic constants without the direct influence of the equilibrium constant value, thereby allowing a more objective data analysis. The effects of the selection of kinetic model, analytical method, and data treatment are discussed.
在材料科学中，Diels-Alder 反应的研究越来越受到关注。主要原因是反应的潜在热可逆性。本研究旨在预测用马来酰亚胺和呋喃基部分修饰的材料的行为，因此探索了呋喃醇与两种 - 羟马来酰亚胺之间 Diels-Alder 反应的 H NMR 和 UV-Vis 溶液研究。从每种技术确定了两个反应体系的速率常数、活化能、熵和形成焓。在 H NMR 中可以区分 和 异构体，并且可以在研究的温度范围内观察到从动力学控制的 Diels-Alder 反应到热力学反应的转变。对其在材料中的应用的影响进行了讨论。所选方法考虑了 Diels-Alder 反应的简化平衡作为动力学模型，使材料科学家能够评估使用反应分子来创建热响应材料的适用性。所提出的方法确定动力学常数而不直接影响平衡常数的值，从而允许更客观的数据分析。讨论了动力学模型、分析方法和数据处理的选择的影响。
