Beijing Red Avenue Innova Co., Ltd. , Unit 1, 2, 3, Building 10, No. 20 Kechuang Fourteenth Street, Beijing Economic-Technological Development Area (BDA) , Beijing 100176 , PR China.
ACS Appl Mater Interfaces. 2018 Jun 13;10(23):19922-19931. doi: 10.1021/acsami.8b02358. Epub 2018 May 29.
Realizing and manipulating a fine dispersion of silica nanoparticles (NPs) in the polymer matrix is always a great challenge. In this work, we first successfully synthesized N, N'-bis[3-(triethoxysilyl)propyl-isopropanol]-propane-1,3-diamine (TSPD), which was a new interface modifier, aiming to promote the dispersion of silica NPs. Through Fourier transform infrared spectroscopy, nuclear magnetic resonance analysis, and mass spectroscopy, we verified that TSPD contains together six ethoxy groups at its two ends. Then, we used this TSPD to modify the pure silica NPs, and this modified silica was abbreviated as D-MS, which is realized by the thermal gravimetric analysis examination, scanning electron microscopy analysis, and dynamic light scattering results. It was clearly observed that D-MS NPs are connected to one another but are not conglutinated tightly, exhibiting a novel predispersed structure with around 1-2 nm certain extent of interparticle distance. Next, we fabricated the following four elastomer nanocomposites such as pure silica/natural rubber (NR) composite (PS-NR), D-MS/NR composite (DMS-NR), bis-(γ-triethoxysilylpropyl)-tetrasulfide (TESPT)-modified silica/NR composite (TS-NR), and TESPT-modified D-MS/NR composite (T&DMS-NR) and found that the Payne effect is the smallest for T&DMS-NR via the combination use of the D-MS and the traditional coupling agent TESPT, which is attributed to its best dispersion state evidenced by the transmission electron microscopy results. Moreover, by measuring a series of other important mechanical performances such as the stress-strain curve, the dynamic strain dependence of the loss factor, and the heat build-up, we concluded that the T&DMS-NR system greatly exceeds those of the three other rubber composites. In general, this new approach provides a good opportunity to prepare a silica/rubber composite with excellent properties in mechanical strength and dynamic behavior by tailoring the fine dispersion of NPs.
实现和操纵聚合物基质中二氧化硅纳米颗粒（NPs）的精细分散一直是一个巨大的挑战。在这项工作中，我们首先成功合成了 N，N'-双[3-（三乙氧基硅基）丙基-异丙醇]-丙烷-1,3-二胺（TSPD），这是一种新的界面改性剂，旨在促进二氧化硅 NPs 的分散。通过傅里叶变换红外光谱、核磁共振分析和质谱分析，我们验证了 TSPD 的两端共含有六个乙氧基。然后，我们使用这种 TSPD 来修饰纯二氧化硅 NPs，修饰后的二氧化硅缩写为 D-MS，这是通过热重分析、扫描电子显微镜分析和动态光散射结果来实现的。可以清楚地观察到 D-MS NPs 相互连接但不紧密结合，呈现出一种具有约 1-2nm 程度的粒子间距离的新型预分散结构。接下来，我们制备了以下四种弹性体纳米复合材料，如纯二氧化硅/天然橡胶（NR）复合材料（PS-NR）、D-MS/NR 复合材料（DMS-NR）、双（γ-三乙氧基硅基丙基）四硫化物（TESPT）改性二氧化硅/NR 复合材料（TS-NR）和 TESPT 改性 D-MS/NR 复合材料（T&DMS-NR），并发现通过结合使用 D-MS 和传统偶联剂 TESPT，T&DMS-NR 的 Payne 效应最小，这归因于透射电子显微镜结果表明其分散状态最佳。此外，通过测量一系列其他重要的力学性能，如应力-应变曲线、损耗因子的动态应变依赖性和发热，我们得出结论，T&DMS-NR 体系在力学强度和动态行为方面大大超过了其他三种橡胶复合材料。总的来说，这种新方法为通过调整 NPs 的精细分散来制备具有优异力学性能和动态行为的二氧化硅/橡胶复合材料提供了一个很好的机会。
