Faculty of Geology, Geophysics and Environmental Protection, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 May 5;252:119491. doi: 10.1016/j.saa.2021.119491. Epub 2021 Jan 21.
The main aim of the present work was to investigate the effect of organo-montmorillonite nanofiller on the cross-linking process of polysiloxane. Two series of model polysiloxane nanocomposites were prepared by incorporating organoclay at different amounts such as 0, 1, 2, 4, and 8 wt% in relation to the weight of the polymer matrix. Poly(methylhydrosiloxane) (PMHS) was cross-linked with two linear vinylsiloxanes of different chain lengths between functional end-groups through hydrosilylation. This reaction was carried out in the presence of Karstedt's catalyst at equimolar ratios of reactive groups. Fourier-transform infrared (FTIR) spectroscopic measurements obtained during the cross-linking processes as well as for the reaction products revealed that the rate of hydrosilylation and its efficiency are influenced by the type of the cross-linking agent used and the amount of organo-montmorillonite introduced into the polysiloxane network. Quantitative analysis of the recorded FTIR spectra showed that as the amount of nanofiller in the polysiloxane matrix increased, the rate and efficiency of the cross-linking process decreased. Swelling measurements confirmed that the increase in the amount of unreacted Si-H groups in the system resulted in a lower cross-link density of the studied materials. Furthermore, X-ray diffraction and transmission electron microscopy were performed to determine the nature of dispersion of organoclay within the studied systems.
本工作的主要目的是研究有机蒙脱土纳米填料对聚硅氧烷交联过程的影响。通过在聚合物基体重量的 0、1、2、4 和 8wt% 等不同比例下掺入有机粘土，制备了两种系列的模型聚硅氧烷纳米复合材料。聚（甲基氢硅氧烷）（PMHS）通过硅氢加成反应与两种具有不同链长的线性乙烯基硅氧烷交联，官能端基之间的反应比例为等摩尔比。在 Karstedt 催化剂的存在下进行该反应。在交联过程中以及反应产物的傅立叶变换红外（FTIR）光谱测量结果表明，硅氢加成反应的速率及其效率受交联剂的类型和引入聚硅氧烷网络中的有机蒙脱土的量的影响。记录的 FTIR 光谱的定量分析表明，随着聚硅氧烷基质中纳米填料的量增加，交联过程的速率和效率降低。溶胀测量证实，体系中未反应的 Si-H 基团数量的增加导致研究材料的交联密度降低。此外，还进行了 X 射线衍射和透射电子显微镜分析，以确定有机粘土在研究体系中的分散性质。
