Farahani Atefe, Jamshidi Masoud, Foroutan Masumeh
Constructional Polymers and Composites Research Lab., School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology (IUST), Tehran, Iran.
School of Chemistry, College of Science, University of Tehran, Tehran, Iran.
Sci Rep. 2023 Jul 24;13(1):11915. doi: 10.1038/s41598-023-39203-5.
Hexagonal boron nitride (h-BN) nanoparticles could induce interesting properties to silicone rubber (SR) but, the weak filler-matrix interfacial interaction causes agglomeration of the nanoparticles and declines the performance of the nanocomposite. In this work, h-BN nanoparticles were surface modified using vinyltrimethoxysilane (VTMS) at different concentrations. Before silane modification, h-BN nanoparticles were hydroxylated using 5 molar sodium hydroxide. The nanoparticles were characterized to assess success of silane grafting. The pure and modified h-BN nanoparticles were applied at 1, 3 and 5 wt% to HTV silicon rubber (SR). The curing, thermal, mechanical and morphological properties and hydrophobicity of the nanocomposites were evaluated. The morphology of the SR nanocomposites was characterized using AFM and FE-SEM analysis. It was found that silane grafting on the h-BN nanoparticles improves crosslink density but declines curing rate index (CRI) of the SR nanocomposite (at 5 wt% loading content) by 0.7 (dN m) and 3.5%, respectively. It also increased water contact angle of the nanocomposites from 97.5° to 107°. The improved nanoparticle-rubber interfacial interactions caused better dispersion of h-BN nanoparticles in SR matrix (at 5 wt%) that enhanced the elongation at break, modulus at 300% and Tg of the SR nanocomposites.
六方氮化硼（h-BN）纳米粒子可赋予硅橡胶（SR）有趣的性能，但是，纳米粒子与基体之间较弱的界面相互作用会导致纳米粒子团聚，从而降低纳米复合材料的性能。在本工作中，使用不同浓度的乙烯基三甲氧基硅烷（VTMS）对h-BN纳米粒子进行表面改性。在硅烷改性之前，用5摩尔的氢氧化钠使h-BN纳米粒子羟基化。对纳米粒子进行表征以评估硅烷接枝的成功与否。将纯的和改性的h-BN纳米粒子以1 wt%、3 wt%和5 wt%的比例添加到高温硫化硅橡胶（SR）中。对纳米复合材料的固化、热、力学和形态性能以及疏水性进行了评估。使用原子力显微镜（AFM）和场发射扫描电子显微镜（FE-SEM）分析对SR纳米复合材料的形态进行了表征。结果发现，h-BN纳米粒子上的硅烷接枝提高了交联密度，但SR纳米复合材料（在5 wt%的负载量下）的固化速率指数（CRI）分别降低了0.7（dN m）和3.5%。它还使纳米复合材料的水接触角从97.5°增加到107°。纳米粒子与橡胶之间改善的界面相互作用使h-BN纳米粒子在SR基体中（在5 wt%时）分散得更好，从而提高了SR纳米复合材料的断裂伸长率、300%模量和玻璃化转变温度（Tg）。
