PMMA/SiO_2透明块体材料的制备及其热性能

以正硅酸乙酯为前驱体,采用无溶剂水解技术,制备出了均一、稳定、透明的SiO_2溶胶,通过透射电子显微镜分析,粒径在100 nm左右;在溶胶中加入甲基丙烯酸甲酯(MMA)和偶氮二异丁腈(AIBN),采用热固化制备了透明的块体PMMA/SiO_2杂化材料,通过差热(DSC)和热重分析(TGA)研究了杂化材料的热性能. DSC结果表明,当体系中的SiO_2质量分数超过20%时,杂化材料无明显的玻璃化转变现象. TGA结果表明,杂化材料的分解温度提高约110 ℃. 透射电子显微镜观察结果表明,无机相均匀分散在有机相中,两相之间没有明显的相分离现象.     

溶胶-凝胶法合成聚甲基丙烯酸甲酯/二氧化钛杂化聚合物材料

由共聚合在PMMA聚合物链段上引入了－Si(OR)₃功能团,通过溶胶－凝胶过程合成了PMMA/TiO₂杂化聚合物材料.溶剂抽提结果表明有化学键存在的杂化材料体系中凝胶的含量很高.通过FTIR测试对材料结构进行了分析,由TGA、DSC测试分析了杂化材料体系中无机组份的含量对材料性能的影响.     

八乙烯基多面体低聚倍半硅氧烷-N-异丙基丙烯酰胺共聚物有机-无机杂化水凝胶的合成与表征

以N-异丙基丙烯酰胺(NIPAM)和八乙烯基笼形低聚倍半硅氧烷(OVPOSS)为单体,通过溶液自由基共聚合成了一系列P(OVPOSS-co-NIPAM)有机-无机杂化水凝胶.采用傅立叶红外光谱(FTIR)、扫描电镜(SEM)、X-射线衍射(XRD)、示差扫描量热仪(DSC)、热重分析仪(TGA)和动态粘弹谱仪(DMA)对其结构与性能进行了研究.结果表明可以通过控制投料比来调节P(OVPOSS-co-NIPAM)杂化水凝胶中POSS的实际含量;P(OVPOSS-co-NIPAM)杂化水凝胶的微观形貌为孔洞结构,随POSS含量的增加,孔径逐渐减小;所合成的P(OVPOSS-co-NIPAM)杂化水凝胶均具有温敏性,随着POSS含量的增加,其最低临界溶解温度(LCST)由33.0℃降低至30.0℃,均低于常规水凝胶(33.7℃);POSS的引入使PNIPAM水凝胶的玻璃化转变温度(Tg)由142℃升至148℃,并改善了其热稳定性和力学强度.     

PMDA-6FHP-DR1/SiO2杂化纳米材料的结构设计和合成

以含氟的二胺5,5′ (六氟异丙基) 二 (2 氨基苯酚)及均苯四甲酸酐(PMDA)为单体,首先合成了经酰胺化的主链上带有活性羟基的含氟聚酰亚胺,再通过Mitsunobu反应将活性生色分子分散红1(DR1)共价链接到聚酰亚胺的侧链骨架上,合成了含氟聚酰亚胺.采用溶胶 凝胶(Sol Gel)技术,并利用偶联剂γ 氨丙基三乙氧基硅烷(APTES)制备带有发色团的和含有硅氧烷端分子的聚酰胺酸,其中的Si(OR)3基经水解、缩合后,与正硅酸乙酯(TEOS)在催化剂作用下反应,经杂化、凝胶后,得到光学透明且热稳定性高的有机/无机杂化材料.将制得的含氟聚酰亚胺/SiO2杂化材料,采用红外光谱(FT IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、示差扫描量热法(DSC),对材料的结构、表面形貌、热性能进行了表征.     

PMMA/TiO_2-SnO_2有机无机杂化材料的制备及表征

以乙酰丙酮为偶联剂,应用溶胶-凝胶法制备了聚甲基丙烯酸甲酯(PMMA)/TiO2-SnO2有机无机杂化材料。采用红外光谱(FT-IR)、紫外光谱(UV)对PMMA/TiO2-SnO2进行表征,并测定其TG性质。结果表明:在聚合反应过程中,有机聚合物和无机组分之间通过共价键相连,并且该杂化材料具有良好的抗紫外光辐射性能和热稳定性能。     

反应性杂化纳米粒子的合成及其对不相容共混物的增容研究

采用八环氧多面体低聚倍半硅氧烷(POSS(epoxy)8)和端羧基聚甲基丙烯酸甲酯(PMMA-COOH)的开环反应,运用Graft-onto的方法合成了一种反应性杂化纳米粒子:四环氧多面体低聚倍半硅氧烷-接枝-四聚甲基丙烯酸甲酯(POSS(epoxy)4-g-PMMA4).通过傅里叶红外光谱仪(FTIR),示差扫描量热仪(DSC),热失重分析仪(TGA),核磁共振波谱仪(1H-NMR)等对反应性杂化纳米粒子的结构进行了表征,结果表明成功合成了POSS(epoxy)4-g-PMMA4.并将上述合成的反应性杂化纳米粒子应用于聚偏氟乙烯/聚乳酸(PVDF/PLLA)不相容体系的增容,运用万能材料试验机、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对其增容原理和效果进行研究,结果表明POSS(epoxy)4-g-PMMA4可以作为PVDF/PLLA不相容体系的反应性增容剂.     

三维有序大孔杂化材料SiW11O8-39-SiO2和γ-SiW10O8-36-SiO2的制备与表征

通过溶胶-凝胶和聚苯乙烯模板等方法制备了含缺位Keggin阴离子SiW11O8-39和γ-SiW10O8-36的三维有序大孔杂化氧化硅复合材料, 并通过紫外漫反射光谱(UV/DRS)、傅里叶变换红外光谱(FTIR)、固体核磁共振波谱(MAS NMR)等手段对其结构进行了表征. 结果表明, 杂化材料中的Keggin阴离子仍保留其基本骨架结构, 但其与氧化硅基体之间存在化学作用. 杂化材料的孔道结构用扫描和透射电子显微镜(SEM和TEM)进行表征, 其平均孔径为(335±50) nm. 对杂化材料孔壁的微孔性通过氮气吸附进行了测定. 此类材料对水溶液中羟基丁二酸的降解反应具有活性, 光催化过程中未发现Keggin阴离子自载体中脱落的现象.     

三维有序大孔杂化材料SiW11O39^8——SiO2和γ—SiW10O36^8——SiO2的制备与表征

通过溶胶 -凝胶和聚苯乙烯模板等方法制备了含缺位 Keggin阴离子 Si W1 1 O8- 3 9和 γ-Si W1 0 O8- 3 6的三维有序大孔杂化氧化硅复合材料 ,并通过紫外漫反射光谱 ( UV/ DRS)、傅里叶变换红外光谱 ( FTIR)、固体核磁共振波谱 ( MAS NMR)等手段对其结构进行了表征 .结果表明 ,杂化材料中的 Keggin阴离子仍保留其基本骨架结构 ,但其与氧化硅基体之间存在化学作用 .杂化材料的孔道结构用扫描和透射电子显微镜 ( SEM和TEM)进行表征 ,其平均孔径为 ( 335± 5 0 ) nm.对杂化材料孔壁的微孔性通过氮气吸附进行了测定 .此类材料对水溶液中羟基丁二酸的降解反应具有活性 ,光催化过程中未发现 Keggin阴离子自载体中脱落的现象 .     

纳米AgBr/PMMA光致变色杂化材料制备与表征

采用本体聚合法制备了纳米AgBr/PMMA(聚甲基丙烯酸甲酯)光致变色杂化材料. XRD分析表明，纳米AgBr/PMMA杂化材料是无定形的. SEM分析表明， AgBr含量不同，杂化材料的断面形貌明显不同，随AgBr含量的增加，杂化材料由韧性断裂向脆性断裂转变. EDS面分析表明， Ag、Br元素在杂化材料中均匀分布.所制备的纳米AgBr/PMMA杂化材料具有一定的光致变色效应.     

PMMA/SiO_2/OV-POSS杂化材料的制备与表征

以乙烯基三氯硅烷为原料水解制得八乙烯基多面体低聚倍半硅氧烷(OV-POSS),将其与经KH570改性的SiO2溶胶和甲基丙烯酸甲酯(MMA)混合均匀,采用热固化的方法制得PMMA/SiO2/OV-POSS杂化材料,通过透射电镜、红外谱图、差热分析和热重分析对材料的微观结构以及热性能进行表征,结果表明:杂化材料结构均匀,有机相和无机相之间通过双键聚合的方式形成了共价键;杂化材料耐热性好,玻璃化转变温度比纯PMMA提高约72℃,分解温度提高约121℃。     

Thermal degradation behaviors of epoxy resin/POSS hybrids and phosphorus–silicon synergism of flame retardancy

Epoxy resin (EP)/polyhedral oligomeric silsesquioxane (POSS) hybrids were prepared based on octavinyl polyhedral oligomeric silsesquioxane (OVPOSS) and phosphorus‐containing epoxy resin (PCEP). The PCEP was synthesized via the reaction between bisphenol A epoxy resin (DGEBA) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO). The structure and morphology of PCEP/OVPOSS hybrids were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. Differential scanning calorimetry revealed that the PCEP/OVPOSS hybrids possessed higher glass transition temperatures than that of PCEP. The thermal stability of the PCEP/OVPOSS hybrids was studied using thermogravimetric analysis (TGA). The TGA results illustrated the synergistic effect of phosphorus–silicon of flame retardancy: phosphorus promotes the char formation, and silicon protects the char from thermal degradation. The thermal degradation mechanism of the PCEP/OVPOSS hybrids was investigated by real time Fourier transform infrared spectra and pyrolysis/gas chromatogram/mass spectrometry (Py‐GC/MS) analysis. It was found that OVPOSS migrated to the surface of the matrix and then sublimed from the surface in nitrogen; whereas, the vinyl groups of OVPOSS were oxidated to form a radical trap which could react with pyrolysis radicals derived from PCEP to form the branched and crosslinked structure in air. The combustion behaviors of the hybrids were evaluated by micro combustion calorimetry. The addition of OVPOSS obviously decreased the value of peak heat release rate and total heat release of the hybrids. Moreover, scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy were used to explore the char residues of the PCEP and the hybrids. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 693–705, 2010     

Synthesis and characterizations of anion exchange organic-inorganic hybrid materials based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)

A series of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based organic-inorganic hybrid materials for anion exchange were prepared through sol-gel process of polymer precursors PPO-Si(OCH₃)₃. PPO-Si(OCH₃)₃ were obtained from the reaction of bromomethylated PPO with 3-aminopropyl-trimethoxysilane (A1110). These polymer precursors then underwent hydrolysis and condensation with additional A1110 to generate hybrid materials. The reaction to produce polymer precursors was identified by FTIR; while FTIR, TGA, XRD, SEM, as well as conventional ion exchange capacity (IEC) measurements were conducted for the structures and properties of the prepared hybrids. TGA results show that this series of hybrid materials possess high thermal stability; XRD and SEM indicate that the prepared hybrid materials are amorphous and the inorganic and organic contents show good compatibility if the ratio between them is proper. The IEC values of the hybrid materials due to the amine groups range from 1.13 mmol/gBPPO (material i) to 4.80 mmol/gBPPO (material iv).     

聚硅氧烷增容母料的制备及应用

火工品引爆时所释放的能量会对结构施加瞬时超过载的冲击,单一的硅橡胶硫化胶缓冲器不能满足阻尼材料性能的使用要求,纯硅橡胶单一硫化或共混硫化胶的损耗因子不足0．15,对应的温域非常小。聚硅氧烷呈螺旋状,表面张力低,但直接使用与其它聚合物相容性差。将硅氧烷进行丙烯酸酯类接枝共聚,可以保持其低温阻尼性能改善高温阻尼性能和拓宽阻尼温域。本文以软聚合物聚硅氧烷为核、硬聚合物丙烯酸酯类为壳,通过乳液接枝共聚的方法制备出具有“强制互容     

可用作水润滑轴承的聚氨酯复合材料的制备

采用聚醚型甲苯二异氰酸酯（TDI）聚氨酯预聚体与3,3′-二氯-4,4′-二氨基二苯基甲烷（MOCA）、氨丙基三乙氧基硅烷（APTEOS）和正硅酸乙酯（TEOS）交联反应,制备耐温型有机-无机杂化聚氨酯复合材料。 通过傅里叶红外光谱仪（IR）、热重分析仪（TGA）、摩擦试验机和硬度计等技术对制备的材料进行了结构表征和性能测试,结果表明,硅氧网络的引入使聚氨酯复合材料的热稳定性得到了提高,同时该材料具有极低的摩擦系数（200 r/min以上,摩擦系数在0.001左右）,硬度在92 A左右。 该有机 无机杂化聚氨酯复合材料已满足了水润滑轴承在耐摩擦、高承载、易加工等方面的要求。     

Hybrid Hydrogels of Porous Graphene and Nickel Hydroxide as Advanced Supercapacitor Materials

Graphene‐based hydrogels can be used as supercapacitor electrodes because of their excellent conductivity, their large surface area and their high compatibility with electrolytes. Nevertheless, the large aspect ratio of graphene sheets limits the kinetics of processes occurring in the electrode of supercapacitors. In this study, we have introduced in‐plane and out‐of‐plane pores into a graphene–nickel hydroxide (Ni(OH)₂) hybrid hydrogel, which facilitates charge and ion transport in the electrode. Due to its optimised chemistry and architecture, the hybrid electrode demonstrates excellent electrochemical properties with a combination of high charge storage capacitance, fast rate capability and stable cycling performance. Remarkably, the Ni(OH)₂ in the hybrid contributes a capacitance as high as 3138.5 F g^?1, which is comparable to its theoretical capacitance, suggesting that such structure facilitates effectively charge‐transfer reactions in electrodes. This work provides a facile pathway for tailoring the porosity of graphene‐based materials for improved performances. Moreover, this work has also furthered our understanding in the effect of pore and hydrogel structures on the electrochemical properties of materials.     

二维有机-无机杂化钙钛矿铁电材料的研究进展

铁电性通常是指电介质材料的自发极化取向随着外加电场发生变化的性能.以自发极化为核心,铁电材料表现出优异的介电响应、热释电性、压电性、电光效应和非线性光学效应等,是一类具有广阔应用前景的功能材料.近年来,二维有机-无机杂化钙钛矿化合物在铁电研究领域崭露头角,逐渐发展为铁电材料的重要组成部分.此类材料具有独特的结构兼容性与...     

Quadruple Photoresponsive Functionality in a Crystalline Hybrid Material: Photochromism,Photomodulated Fluorescence,Magnetism and Nonlinear Optical Properties

As promising photoresponsive materials and potential smart materials, hybrid photochromic materials (HPMs), especially for crystalline HPMs (CHPMs), have been broadly explored for their potential in inheriting the merits of each constituents, and intriguing photomodulated functionality. Hitherto, the photoresponsive functionality in explored CHPMs mainly concentrate on dyad combination. By contrast, triple or quadruple photoresponsive properties are very rare because of the limited compatibility of multiple photoresponsive functionality in a single system. In this work, the electron-transfer (ET) and crystal engineering strategies were utilized to predesign CHPMs with multiple photoresponsive properties via the collaboration of paramagnetic metal ion (Dy³⁺), electron-donor (ED) ligand (benzene-1,2,3-tricarboxylic acid, H₃BTA) and electron-acceptor (EA) ligand (1,10-phenanthroline, phen). The resulting complex [Dy(BTA)(phen)₂]⋅2H₂O ( 1 ) shows hybrid chain with the intrachain Dy³⁺ ions bridged and chelated by tricarboxylate and phen ligands, respectively. After photostimuli, the ET between tricarboxylate and phen results in photogenerated radicals and the resultant quadruple photoresponsive properties. Considering the abundant resources of paramagnetic metal ions, ED- and EA-ligands, this work provides a general method to construct CHPMs with multiple photoresponsive performances via the collaboration of each unit under the guidance of ET and crystal engineering strategies.     

Preparation and characters of hyperbranched polyester‐based organic‐inorganic hybrid material compared with linear polyester

To compare the properties of hyperbranched polymers with linear oligomers for preparing organic‐inorganic hybrids, hyperbranched aliphatic polyester (Boltorn^TM H20) and linear polyester hexa‐acrylate (EB830) were selected as organic components for preparing UV‐curable transparent hybrid materials using 3‐(trimethoxysilyl) propylmethacrylate as a coupling agent via a sol‐gel process. The prehydrolyzed product of tetraethoxysilane was used as an inorganic component. The effects of inorganic content on the morphologies, thermal behaviors, photopolymerizaiton kinetics and mechanical properties of the hybrids were investigated. The results show that for hyperbranched polyester‐based hybrids, the organic phase shows much better compatibility with inorganic phase even at high inorganic component content due to its special spheral shape and plenty of functional end groups, compared with linear EB830‐based hybrids. Copyright © 2004 John Wiley & Sons, Ltd.