The compatibility between polymer matrix and filler is a vital issue in the fabrication of composites with desirable properties. To enhance the interfacial adhesion between matrix and filler, various surface modification treatments are applied. The objective of this study was to increase the affinity of silica and poly(urethane-urea)s (PUUs), thereby improving the mechanical properties of the resulting composites. Stepwise surface modification of mesoporous silica with amine-containing dendrimers was done. Various techniques were used to confirm the surface-modified structure during the stepwise reaction. Additionally, the N₂ adsorption–desorption method indicated a gradual reduction in surface area, pore diameter and pore volume of the particles, which warrants the gradual propagation of the dendrimers on the surface and also inside the pores. A type IV isotherm was obtained in this analysis. Two types of pre-synthesized PUUs were chosen for composite preparation containing the surface-modified silica with 0.5, 1, 2.5 and 5 wt% concentrations. Due to the high affinity of the dendrimers containing amine moieties on the particles with polyurethane, a proper dispersion of particles in the matrix was achieved based on scanning electron micrographs. Tensile measurements showed an increased Young's modulus and strength of polyurethane films as a result of addition of the particles. However, no significant improvement in the tensile performance of the composites was seen above 2.5 wt% particle loading due to some particle aggregations. © 2021 Society of Industrial Chemistry.

中文翻译：

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介孔二氧化硅的逐步表面改性及其在聚（氨酯-脲）复合膜中的应用

聚合物基体和填料之间的相容性是制造具有所需性能的复合材料的关键问题。为了增强基体和填料之间的界面附着力，应用了各种表面改性处理。本研究的目的是增加二氧化硅和聚（氨基甲酸酯 - 脲）（PUU）的亲和力，从而改善所得复合材料的机械性能。用含胺树枝状聚合物对介孔二氧化硅进行了逐步表面改性。在逐步反应过程中，使用各种技术来确认表面改性结构。此外，N ₂吸附-解吸方法表明颗粒的表面积、孔径和孔体积逐渐减小，这保证了树枝状大分子在表面和孔内的逐渐传播。在该分析中获得了 IV 型等温线。选择两种类型的预合成 PUU 用于复合制备，其中含有 0.5、1、2.5 和 5 wt% 浓度的表面改性二氧化硅。由于颗粒上含有胺部分的树枝状聚合物与聚氨酯的高亲和力，基于扫描电子显微照片实现了颗粒在基质中的适当分散。拉伸测量表明，由于添加了颗粒，聚氨酯薄膜的杨氏模量和强度增加。然而，由于一些颗粒聚集，在高于 2.5 wt% 的颗粒负载时，未发现复合材料的拉伸性能有显着改善。© 2021 工业化学学会。