POSS基聚合物的热性能和阻燃性

本文介绍了POSS单体和POSS基聚合物的结构、性能和制备方法。重点阐述了各类POSS基聚合物以及它们的热性能。同时简单介绍了POSS对聚合物阻燃性的影响,分析了POSS提高聚合物热性能和阻燃性的原因,并展望了POSS基聚合物的发展方向。     

多面体低聚倍半硅氧烷在涂料领域的研究进展

多面体低聚倍半硅氧烷(POSS)作为一种有机无机杂化纳米材料,由于其独特的结构特性及改善涂料综合性能的优势而备受关注。本文介绍了POSS的结构和特性,综述了POSS的合成方法,根据官能团数量的不同将合成方法分为3种;分析了POSS改性聚合物的方式以及其改性聚合物在涂料领域的研究进展,通过POSS的改性可以提高涂料的热稳定性、力学性能、阻燃性能等,并展望了其发展趋势。     

POSS/聚合物复合材料的制备以及在尼龙中应用的研究进展

多面体低聚倍半硅氧烷(polyhedral oligomeric silsesquioxane,POSS)是一种具有独特中空刚性结构的纳米级材料,作为无机-有机的新型杂化材料,其可设计的分子杂化结构使得POSS能够在聚合物基体中达到分子水平或纳米级别的良好分散,有效提升材料的表面性能、热性能、介电性能和力学性能等,极大地拓宽了在聚合物中的应用领域。本文主要针对POSS的合成制备方法、功能化改性方法、POSS形貌与性能的关系、POSS/尼龙复合材料的制备方法等进行综述。主要介绍POSS的合成方法、官能化方法及POSS/尼龙复合材料的制备方法及结构与性能的关系。未来随着POSS官能化方法的改进必然能够将POSS引入更多的聚合物基体内并实现更好的分散,POSS在聚合物中的应用范围将不断扩大。     

基于多面齐聚倍半硅氧烷的形状记忆聚合物的研究进展(下)

形状记忆聚合物(Shape Memory Polymers,SMPs),作为一类具有刺激响应性的智能材料,越来越受到研究者的青睐。由于其独特的优异性能可被广泛的应用到生物医疗、纺织、航空等领域。多面齐聚倍半硅氧烷(Polyhedral Oligomeric Silsesquioxanes,POSS)是具有纳米尺寸的有机-无机杂化笼型分子。POSS可通过化学共聚或者物理共混引入到聚合物中,使聚合物的多种性能包括形状记忆性能得到改善。本文介绍了POSS在不同形状记忆聚合物的研究进展,详细探讨了POSS的引入对聚合物的形状记忆性能的影响,并展望了未来其可能的研究重点和发展方向。     

基于多面齐聚倍半硅氧烷的形状记忆聚合物的研究进展(上)

形状记忆聚合物(Shape Memory Polymers,SMPs),作为一类具有刺激响应性的智能材料,越来越受到研究者的青睐。由于其独特的优异性能可被广泛的应用到生物医疗、纺织、航空等领域。多面齐聚倍半硅氧烷(Polyhedral Oligomeric Silsesquioxanes,POSS)是具有纳米尺寸的有机-无机杂化笼型分子。POSS可通过化学共聚或者物理共混引入到聚合物中,使聚合物的多种性能包括形状记忆性能得到改善。本文介绍了POSS在不同形状记忆聚合物的研究进展,详细探讨了POSS的引入对聚合物的形状记忆性能的影响,并展望了未来其可能的研究重点和发展方向。     

POSS及其改性聚合物的研究进展

介绍了多面体倍半硅氧烷（POSS）的合成方法,综述了POSS改性聚合物的一些优异性能,总结了近3年国内的研究成果,展望了POSS改性聚合物的研究前景。     

POSS/聚合物复合材料的研究进展

介绍了POSS/聚合物复合材料的基本特性,以及常见的几种制备方法 (物理共混法和化学共聚法),指出了POSS/聚合物复合材料相对于常规纳米高分子复合材料在性能上的差异。对POSS/聚合物复合材料在发展过程中存在的一些问题进行了分析并展望了发展趋势。     

多面体低聚倍半硅氧烷研究的最新进展

多面体低聚倍半硅氧烷（POSS）是目前研究相当活跃的一类有机—无机杂化结构的纳米粒子。通过官能化POSS直接聚合或利用化学反应将POSS结合到聚合物中以及作为纳米添加剂与其他材料共混,可制备多种多样的聚合物/POSS纳米复合材料。POSS的引入能有效降低材料的介电常数,改善材料的热性能、机械性能、耐火性、防水防油性、加工性能、牢固度和透明度等;因此,POSS被认为是一种优良的纳米构筑材料。本文对POSS研究的近况进行了简要概述。     

基于POSS骨架的多孔材料研究进展

多面体笼型倍半硅氧烷(POSS)分子有一类似于二氧化硅的无机内核,该核被有机基团所包围。由于POSS本身所具备的杂化特性和纳米尺度的特征,与大多数聚合物具有良好的相容性,POSS引入聚合物体系后可以显著改善聚合物基体的性能。本文综述了基于POSS骨架的多孔材料的研究进展。     

官能化POSS的制备及其在有机硅材料中的应用进展

笼型低聚倍半硅氧烷(POSS)是一种新型纳米有机-无机杂化材料,具有独特的物理化学性质。将官能化POSS用于有机硅材料的制备与改性,能够显著改善有机硅材料的物理化学性能,拓宽其应用领域。本文首先总结了POSS的制备方法,重点对聚合物改性中常用的官能化POSS的制备进行了综述,包括:八苯基POSS、八乙烯基POSS、八氢基POSS、环氧基POSS、氨基POSS、异氰酸酯基POSS和单官能化POSS。然后从物理改性与化学改性两方面总结了官能化POSS在有机硅材料中的应用进展。最后对官能化POSS在制备及应用领域的发展方向进行了展望。目前,POSS已经在聚合物改性领域展现出巨大的潜力,随着新型POSS化合物的出现,官能化POSS在有机硅材料领域的应用将取得更大的进展。     

Thermal and morphological properties of high‐density polyethylene/ethylene–vinyl acetate copolymer composites with polyhedral oligomeric silsesquioxane nanostructure

The demand for improved properties of common polymers keeps increasing, and several new approaches have been investigated. In the study reported here, composites with a polymer matrix comprising a blend of high‐density polyethylene with ethylene–vinyl acetate copolymer (EVA), and with polyhedral oligomeric silsesquioxane (POSS) as a nanostructure, were processed and characterized in terms of their thermal and morphological properties. For the preparation of the composites, the concentrations of the blend components (0, 50 and 100 wt%) and of the POSS (0, 1 and 5 wt%) were varied. X‐ray diffraction results indicated that the presence of EVA in the composites led to the appearance of crystalline domains at lower POSS concentrations. Transmission and scanning electron microscopy showed that samples with 1 wt% of POSS had a homogeneous distribution in the polymer matrix with average dimensions of ca 150 nm. However, the formation of aggregates occurred in samples with 5 wt% of POSS. Differential scanning calorimetry and thermogravimetic analyses indicated that the POSS did not affect the melt and degradation temperatures of the polymer matrix. POSS underwent aggregation at higher concentrations during the composite processing, indicating a solubility limit of around 1 wt%. The presence of EVA in the composite favors POSS aggregation due to an increase in the polarity of the polymer matrix. Copyright © 2009 Society of Chemical Industry     

The influence of POSS type on the properties of PLA

In this study, the effects of reactive and non‐reactive poly(hedral oligomeric silsesquoxane) (POSS) type and their loading level on the mechanical, morphological and thermal properties of PLA composites were investigated for the first time in the literature. A decrease in the melt viscosity of PLA was obtained from the vertical force measurements in the presence of POSS particles except for high O‐POSS loading level. This played an important role for power consumption during micro‐compounding process. The mechanical test results showed that, the elastic‐modulus and yield strength of the PLA/POSS composites were lower than pure PLA in most cases. Moreover, a significant improvement in Izod impact strength of PLA composites was achieved by incorporation of POSS particles into PLA regardless of POSS type. Morphological analysis showed that POSS particles dispersed homogeneously in polymer matrix for all compositions. The glass transition temperature of PLA decreased with the addition of POSS particles. POSS particles also enhanced the decomposition temperature of PLA. POLYM. COMPOS., 37:1497–1506, 2016. © 2014 Society of Plastics Engineers     

POSS改性聚合物复合材料力学性能研究进展

介绍了笼型倍半硅氧烷（POSS）的结构、分类以及POSS改性聚合物力学性能的特点和机理,综述了POSS改性聚合物（包括聚烯烃、环氧树脂、聚丙烯酸酯、聚氨酯等）复合材料力学性能的研究进展,并展望了POSS改性聚合物复合材料的发展前景。     

Zirconium-Embedded Polyhedral Oligomeric Silsesquioxane Containing Phosphaphenanthrene-Substituent Group Used as Flame Retardants for Epoxy Resin Composites

A zirconium hybrid polyhedral oligomeric silsesquioxane derivative (Zr–POSS–bisDOPO) is synthesized by the corner-capping and Kabachnik–Fields reactions. It is characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR), and then used as a flame retardant in diglycidyl ether of bisphenol A (DGEBA) to endow epoxy resin (EP) with flame retardancy. The flame retardancy, thermal stability, and mechanical properties of the cured EP/Zr–POSS–bisDOPO composites are investigated. The results show that when Zr–POSS–bisDOPO is added by 5–7 wt%, the EP/Zr–POSS–bisDOPO composites pass the UL-94 V-0 rating test. In addition, they have a better flame-retardant effect than pure EP. The combination of Zr atom embedded in the Si O cubic cage and the two phosphaphenanthrene substituent groups in one corner of cubic cage is expected to realize the Zr/Si/P ternary intramolecular hybrid synergistic effect and achieve the possibility of dispersing metal–POSS cages at a sub-micrometer-scale level into polymer matrix. It also proves that Zr–POSS–bisDOPO produces phosphorus-containing free radicals and terminates the chain reactions in gas phase. Meanwhile the Si O Si and Zr O units are retained in the solid phase, which promote the char formation and enhance the flame retardancy. This kind of Zr-doped POSS will be helpful for developing the new metal–POSS hybrid flame-retardant and polymer composites.     

A novel hybrid functional nanoparticle and its effects on the dielectric,mechanical, and thermal properties of cyanate ester

A novel hybrid functional nanoparticle (denoted POSS‐MPS) was synthesized by aminopropyl‐functionalized mesoporous silica (AP‐MPS) with glycidyl polyhedral oligomeric silsesquioxane (G‐POSS). The G‐POSS was employed as molecular caps to envelop the MPS and improve the interaction with the polymer matrix. The POSS‐MPS hybrids were designed to improve the properties of cyanate ester (CE) without affecting its inherent properties. The POSS‐MPS/CE composites exhibited excellent improvement in dielectric properties, mechanical properties, and thermal properties due to increase of voids volume in the composites and reinforcement of interface interaction between organic and inorganic phase. The dielectric constant (κ) and loss factor (tan δ) of composites with 4 phr of POSS‐MPS reduced to 2.78 and 0.008 in comparison to pure CE with the value of 3.27 and 0.012, respectively. Moreover, the composites exhibited 14.3, 4.9, 57.5, and 8.7% enhancement in flexural strength, flexural modulus, impact strength, and glass transition temperature (T_g) in comparison to pure CE, respectively. The results manifested that introduction of POSS‐MPS into CE exhibited toughening and reinforcing effects on the composites. POLYM. COMPOS., 37:2142–2151, 2016. © 2015 Society of Plastics Engineers     

溶液共混法笼状硅氧烷低聚物/硅橡胶复合材料的分散性

通过溶液共混法制备了笼状硅氧烷低聚物（POSS）／硅橡胶复合材料，用X射线衍射仪和透射电子显微镜研究了该材料的分散状况，考察了POSS质量分数以及烘干温度、溶剂含量对POSS在硅橡胶中分散状况的影响。结果表明，POSS质量分数越低，烘干温度越高，越有利于抑制POSS的结晶．进而有利于制备POSS精细分散的P0ss／硅橡胶复合材料；而溶剂含量越少时，更多的POSS以晶体形式从溶剂中析出，从而使得POSS的结晶程度更显著。     

Mechanical,thermal, and viscoelastic response of novel in situ CTBN/POSS/epoxy hybrid composite system

The present study focuses on the preparation of a novel hybrid epoxy nanocomposite with glycidyl polyhedral oligomeric silsesquioxane (POSS) as nanofiller, carboxyl terminated poly(acrylonitrile‐co‐butadiene) (CTBN) as modifying agent and diglycidyl ether of bisphenol A (DGEBA) as matrix polymer. The reaction between DGEBA, CTBN, and glycidyl POSS was carefully monitored and interpreted by using Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). An exclusive mechanism of the reaction between the modifier, nanofiller, and the matrix is proposed herein, which attempts to explains the chemistry behind the formation of an intricate network between POSS, CTBN, and DGEBA. The mechanical properties, such as tensile strength, and fracture toughness, were also carefully examined. The fracture toughness increases for epoxy/CTBN, epoxy/POSS, and epoxy/CTBN/POSS hybrid systems with respect to neat epoxy, but for hybrid composites toughening capability of soft rubber particles is lost by the presence of POSS. Field emission scanning electron micrographs (FESEM) of fractured surfaces were examined to understand the toughening mechanism. The viscoelastic properties of epoxy/CTBN, epoxy/POSS, and epoxy/CTBN/POSS hybrid systems were analyzed using dynamic mechanical thermal analysis (DMTA). The storage modulus shows a complex behavior for the epoxy/POSS composites due to the existence of lower and higher crosslink density sites. However, the storage modulus of the epoxy phase decreases with the addition of soft CTBN phase. The T_g corresponding to epoxy‐rich phase was evident from the dynamic mechanical spectrum. For hybrid systems, the T_g is intermediate between the epoxy/rubber and epoxy/POSS systems. Finally, TGA (thermo gravimetric analysis) studies were employed to evaluate the thermal stability of prepared blends and composites. POLYM. COMPOS., 37:2109–2120, 2016. © 2015 Society of Plastics Engineers     

Influence of methacryl polyhedral oligomeric silsesquioxane on the thermal and mechanical properties of methylsilicone resin

A methacryl polyhedral oligomeric silsesquioxane (POSS)‐reinforced methylsilicone resin was prepared in this work. The structures of the obtained products were confirmed with Fourier transform infrared and atomic force microscopy. The influence of methacryl‐POSS on the thermal behavior of the methylsilicone resin was studied by thermogravimetric analysis and isothermal thermogravimetric analysis. The results showed that the thermal stability of the methylsilicone resin was improved, and the degree of thermooxidative degradation was lowered; this was due to the retardation of polymer chain motion and the formation of a protective layer of SiO₂. The interlaminar shear strength and flexural strength of quartz fiber/methylsilicone resin composites were tested to determine the effects of methacryl‐POSS on the mechanical properties of methylsilicone resin. The results revealed that the mechanical properties of the methylsilicone composites also increased obviously after the incorporation of methacryl‐POSS because of the increase in the cure degree and rigidity of the resin. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of POSS/Quartz fibers/cyanate ester resins laminated composites

Quartz fibers (QFs) and two polyhedral oligomeric silsesquioxane (POSS) (epoxy‐POSS and hydroxy‐POSS) are performed to regulate the dielectric properties, heat resistance, and mechanical properties of cyanate ester (CE) resins. With the introduction of POSS, the dielectric constant and dielectric loss tangent values of the POSS/QFs/CE laminated composites are decreased obviously. The heat resistance properties and flexural strength values of the laminated composites are increased, but the interlaminar shear strength values of the laminated composites are decreased slightly. The EP‐POSS/QFs/CE laminated composites have relatively better dielectric, heat resistance, and mechanical properties than those of HO‐POSS/QFs/CE laminated composites. POLYM. COMPOS., 36:2017–2021, 2015. © 2014 Society of Plastics Engineer     

笼状硅氧烷/硅橡胶复合材料的非等温结晶性能

采用溶液共混法制备了笼状硅氧烷低聚物(POSS)/硅橡胶复合材料,用差示扫描量热仪在不同降温速率下研究了POSS/硅橡胶复合材料的非等温结晶性能,考察了POSS质量分数分别为5%(试样P5)、10%(试样P10)和30%(试样P30)时对复合材料非等温结晶参数和活化能的影响,并选用Ozawa及Ozawa-Avrami联合法对POSS/硅橡胶的非等温结晶性能进行了分析。结果表明,Ozawa-Avrami联合方法适合描述POSS/硅橡胶的非等温结晶现象;POSS/硅橡胶复合材料成核速率的大小依次为P5、P15和P30,生长速率则相反,而结晶速率大小依次为P30、P5和P15。