Centro de Astrobiología (INTA-CSIC), Dpto. Evolución Molecular, Ctra. Torrejón-Ajalvir, km 4, Torrejón de Ardoz, 28850 Madrid, Spain.
Phys Chem Chem Phys. 2018 Jun 27;20(25):17353-17366. doi: 10.1039/c8cp01662c.
The kinetics of the reaction of the synthesis of HCN polymers in aqueous medium at high temperatures have been analysed to ascertain a suitable model for this material, for which it was recently demonstrated that prebiotic chemistry may now be adapted in the development of a new generation of high performance coatings and adhesives with biomedical applications. These experimental conditions were chosen for the simplicity of the reagents, being particularly convenient in regard to potential industrial scale-up of coating technology, where these polymers have revealed an interesting field of application. The kinetics of the precipitation polymerization of HCN in water were studied under isothermal conditions at four different temperatures between 75 °C and 90 °C throughout gravimetric measurements. The use of the Kamal-Sourour autocatalytic kinetic model was proposed, properly describing the overall formation process of this insoluble HCN polymer. All of the kinetic parameters, including reaction orders, kinetic constants and activation energy, were determined for the cross-linking polymerization reaction under study, and a relevant autocatalysis effect was observed. An isoconversion method was also used to analyse the variation of the global activation energy with conversion; and characterization by means of elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was carried out. This study demonstrates the autocatalytic, robust and straightforward character of this heterogeneous aqueous HCN polymerization, and to the best of our knowledge, this report describes the first time that a systematic and extended kinetic analysis has been conducted to obtain a more comprehensive and deeper understanding of this complex reaction, which is of great interest to the origin of life and, currently, to materials science.
已经分析了高温下水相介质中 HCN 聚合物合成反应的动力学，以确定适合该材料的模型。最近有人证明，前生物化学现在可以适应新一代具有生物医学应用的高性能涂料和粘合剂的开发。选择这些实验条件是因为试剂的简单性，特别是在涂层技术的潜在工业规模扩大方面，这些聚合物已经显示出了一个有趣的应用领域。在 75°C 至 90°C 的四个不同温度下，通过重量法研究了氰化氢在水中的沉淀聚合的等温动力学。提出了使用 Kamal-Sourour 自催化动力学模型，该模型可以很好地描述这种不溶性 HCN 聚合物的整体形成过程。确定了所研究的交联聚合反应的所有动力学参数，包括反应级数、动力学常数和活化能，并观察到相关的自催化效应。还使用等转化率法分析了全局活化能随转化率的变化；并通过元素分析、傅里叶变换红外（FTIR）光谱和扫描电子显微镜（SEM）进行了表征。这项研究证明了这种异相水相 HCN 聚合的自催化、稳健和简单的性质，据我们所知，这是首次进行系统和扩展的动力学分析，以更全面、更深入地了解这种复杂反应，这对生命起源具有重要意义，目前对材料科学也具有重要意义。
