机械性能

AbstractThe preparation of highly compatible polydimethylsiloxane/epoxy system has been a challenging task. Here, we designed and synthesized a vinyl-containing bifunctional epoxy resin, which was chemically bonded with polydimethylsiloxane by hydrosilylation. A silicone-epoxy block hybrid network with restricted micromorphology and outstanding macro-performance was formed. The phase separation scale of polydimethylsiloxane/epoxy system was strictly restricted by molecular structure design and the modified PDMS was transparent.

Abstract\n\t\t\t\t\n\t\t\t\t\tA novel cross-linker octa[(trimethoxysilyl)ethyl]-POSS (OPS) based on a Vinyl-POSS derivative was firstly prepared via hydrosilylation chemistry. The novel POSS cross-linker was applied to hydroxyl terminated polydimethylsiloxane (HPDMS) matrix to prepare a series of novel RTV silicone rubbers. The chemical incorporation of novel POSS cross-linker into PDMS by hydrolytic condensation reaction was verified by attenuated total reflection (ATR) infrared spectroscopy.

Polystyrene-graft-polydimethylsiloxane (PS-g-PDMS) copolymers with different PDMS content were syn-thesized by the radical bulk copolymerization of PDMS macromonomer and styrene. The copolymers were charac-terized by Fourier transform infrared (FT-IR),1H-nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), transmission electron microscopy (TEM) and the mechanical properties of the copolymers were also carried out.

A Study on the Scratch Resistance by Additives of PDMS and Grain Patternscratch resistance;PDMS;grain pattern;polypropylene(PP);mechanical properties;In this study, we have investigated mechanical properties and scratch resistance of polypropylene compounds by two types of masterbatch with different molecular weight of PP. Masterbatches were prepared with polypropylene(PP) and polydimethylsiloxane(PDMS) by melt mixing. Mechanical properties and scratch behavior were examined with UTM and polarizing microscope.

摘要\n制备高相容性的聚二甲基硅氧烷/环氧体系一直是一项具有挑战性的任务。在此，我们设计合成了一种含乙烯基双功能环氧树脂，通过硅氢加成反应与聚二甲基硅氧烷发生化学键合。形成了微观形貌受限、宏观性能优异的硅-环氧嵌段杂化网络。聚二甲基硅氧烷/环氧体系的相分离尺度受到分子结构设计的严格限制，改性后的PDMS透明。力学性能测试结果表明，复合材料的拉伸强度、断裂伸长率和剪切强度分别提高了39.1 %、7.8 %和29.2 %。更为重要的是，杂化材料的初始热分解温度升高，800℃的热残馀量保持在较高水平。所有这些结果表明，我们制备了一种透明、高性能的聚二甲基硅氧烷材料，有望应用于耐热胶粘剂、透明表面涂层等诸多领域。

The Pickering emulsion approach has been frequently employed to fabricate various emulsions. However, the direct formation of cross-linked polymer films from Pickering emulsions and double functions (emulsified and mechanical reinforcement) of Pickering agents have not been sufficiently reported.;Fumed silica was co-modified with vinyltrimethoxysilane (VTMS) and hexamethyl disilylamine (HMDS) and was further adopted to emulsify vinyl or hydrogen dimethicone.

摘要\n本研究针对0 ~ 1.5NaY分子筛wt %的薄膜，制备了聚二甲基硅氧烷( PDMS )和NaY分子筛掺杂复合膜。所有膜均采用衰减全反射傅里叶变换红外光谱( FTIR )、X射线衍射、扫描电镜、热重/差热分析等方法进行表征。FTIR光谱结果表明，PDMS基体与NaY分子筛之间存在物理相互作用。此外，利用光子传输技术研究了纯PDMS和PDMS / NaY复合材料的成膜情况。计算了空穴闭合和互扩散阶段对应的激活能。NaY沸石添加薄膜导致力学性能显著提高，拉伸强度和杨氏模量均提高了3倍。还考察了薄膜的热性能，在PDMS基体中加入NaY分子筛可显著提高复合膜的热稳定性。J . Appl . Polym。Sci . 2020、137、48549。

摘要\n具有高电子迁移率的二维氧化铋( Bi2O2Se )在未来高性能、柔性的电子和光电子器件中具有优势。然而，薄的Bi2O2Se片的转移是相当困难的，限制了其力学性能的测量和在柔性器件中的应用探索。在此，我们发展了一种可靠有效的聚二甲基硅氧烷( PDMS )介导的方法，可以将Bi2O2Se薄片从生长的基底转移到目标基底上，如微机电系统基底。转移薄片的高保真度源于PDMS薄膜的高粘结能和柔韧性。首次采用纳米压痕法研究了二维Bi2O2Se的力学性能。研究发现，在二维半导体中，少层Bi2O2Se具有较大的本征刚度，为18 ~ 23 GPa，杨氏模量为88.7 ± 14.4 GPa，与理论值相符。此外，少层Bi2O2Se能够承受超过3 %的高径向应变，表现出优异的柔韧性。2D Bi2O2Se力学性能可靠传递方法和文献的发展，共同填补了这一新兴材料力学性能理论预测和实验验证的空白，将推动基于2D Bi2O2Se的柔性电子和光电子领域。