笼型倍半硅氧烷及其在阻燃聚合物中的应用

笼型倍半硅氧烷(POSS)是一种新型的有机-无机杂化材料,是基于化学键作用形成的分子内杂化结构。由于其独特的分子结构,与聚合物复配后形成的杂化材料不但能够明显改善聚合物基体的力学性能、加工性能和光电性能,同时能够显著提高聚合物的耐热性能和燃烧性能。本文简要综述了POSS单体的结构特点及几种在阻燃聚合物中常用到的带有特种结构官能团POSS的合成方法,分析了POSS的加入对聚合物阻燃机理的影响,重点介绍了近年来POSS在阻燃聚合物中的应用研究进展,并展望了今后的研究方向和重点。     

含POSS侧基的非环二烯烃易位聚合及离子型杂化聚合物表征

基于七异丁基-胺丙基-多面体低聚倍半硅氧烷(POSS-NH₂)与溴丁烯或溴代十一烯反应, 一步法合成了含POSS侧基的两种杂化二烯烃. 以钌卡宾络合物为催化剂的非环二烯烃易位(ADMET)聚合, 短链二烯烃未能发生, 而长链二烯烃能顺利实现. 将杂化二烯烃转变为离子型杂化二烯烃, 其ADMET聚合活性较高, 随着反应时间延长, 聚合物分子量明显增大, 分子量分布变窄, 体现了逐步聚合的特征. 核磁共振分析揭示了聚合物的不饱和结构和聚合反应的变化过程. 主链不饱和的无定形聚合物, 经氢化作用转变为饱和的离子型杂化聚乙烯, POSS基团精确地连接在聚乙烯骨架的侧位上, 且POSS基团和聚乙烯骨架均表现出较强的结晶能力. 这种离子型杂化聚乙烯具有球形的单分子或聚集形态, 可直接构筑纳米尺度的聚合物材料.     

多面体齐聚倍半硅氧烷的合成及应用研究进展

多面体齐聚倍半硅氧烷(Polyhedral Oligomeric Silasesquioxane,POSS)本身作为一种分子水平上的纳米有机/无机杂化体,由于几乎能够改性所有传统材料而引起人们的极大关注。这种杂化体可以通过多种合成方法得到,为新型杂化材料的设计提供了便利。本文综述了近年来有关POSS的合成方法、POSS基聚合物的研究及其在电子材料、航空航天材料、多孔材料、发光材料等方面的应用研究进展并对其发展前景予以展望。     

含多面体低聚倍半硅氧烷杂化毛细管整体柱的制备及修饰

本文采用自由基聚合法原位制备了两种杂化毛细管整体柱。首先以含有一个甲基丙烯酸基团的多面体低聚倍半硅氧烷(POSS)试剂(Bu-POSS)为单体、以含有多个甲基丙烯酸基团的POSS试剂(POSS-MA)为交联剂在二元致孔剂(正丙醇/聚乙二醇400)和引发剂(偶氮二异丁腈)存在下发生热引发聚合,在毛细管中形成聚(Bu-POSS-co-POSS-MA)杂化整体柱;另外仅以POSS-MA为单体在相同条件下制备聚(POSS-MA)杂化整体柱,并将这两种杂化整体柱应用于小分子的毛细管液相色谱(cLC)分析。结果表明,含POSS杂化整体柱具有制备简单、重现性好以及稳定性高的特点。此外,利用聚(POSS-MA)杂化整体柱表面剩余的甲基丙烯酸基团,可以将功能单体(甲基丙烯酸硬脂酸酯等)化学键合到整体柱上,不但可以提高色谱柱效,而且使其具有不同的选择性。本文所发展的以POSS试剂为原料采用自由基聚合法制备杂化整体柱的方法为新型杂化整体柱的制备提供了一种新思路。     

POSS聚合物及其新进展

POSS 作为一种特殊的有机/无机杂化纳米构件备受关注。本文总结了近几年有关探索POSS聚合物结构与性能之间关系的研究进展，并重点综述了POSS在有机半导体材料领域的应用。     

六面体倍半硅氧烷(POSS)杂化材料

POSS作为一种新型的有机/无机杂化材料在近10年的研究中引起了人们的极大关注，这种杂化材料可以通过不同的合成方法获得，为材料的设计提供了极大的便利。本文综述了近几年来POSS基有机/无机杂化的电致发光材料、液晶材料和POSS衍生物的自组装行为的研究进展，指出这类材料由于制作方便和热力学性能优良，在未来高科技领域中必有宽广的应用前景。     

含POSS光刻胶材料研究进展

光致抗蚀剂又称光刻胶,是微电子加工过程中的关键材料。多面体低聚倍半硅氧烷（POSS）是一种具有规则的笼型结构的聚合物增强材料,由POSS改性的聚合物实现了有机-无机纳米杂化,POSS刚性结构的引入阻碍了聚合物分子的运动,可以显著提高聚合物的玻璃化转变温度（T_g）,降低聚合物的介电常数,提高聚合物的力学性能,也提高了含POSS光致抗蚀剂的耐蚀刻性。基于这些优点,含POSS的光刻胶材料得到广泛关注。本文对含POSS光刻胶的研究进展作了简要介绍。     

蝌蚪型POSS接枝含氟丙烯酸酯类杂化聚合物多孔膜的制备研究

以本实验室合成的3种结构的蝌蚪型POSS杂化聚甲基丙烯酸三氟乙酯(POSS-PTFEMA)、POSS杂化聚甲基丙烯酸三氟乙酯嵌段共聚聚甲基丙烯酸甲酯(POSS-PMMA-PTFEMA)及POSS杂化聚甲基丙烯酸甲酯嵌段共聚聚甲基丙烯酸三氟乙酯为成膜材质,利用呼吸图案法制备规整结构的蜂窝状聚合物多孔薄膜.利用扫描电镜(SEM)对薄膜表观形貌进行观察,分析了孔形貌的影响因素,并研究了多孔膜的疏水疏油性和耐温性.研究表明,以氯仿为成膜溶剂,3种不同结构的杂化聚合物均可以在较大的浓度范围下(5~30 mg/mL)制备规整的杂化聚合物多孔膜,膜的孔径随聚合物浓度的增大而增大;聚合物POSS-PTFEMA由于化学结构中含有最多的TFEMA结构单元,其规整性最好;相对疏水的硅片也有利于这类疏水的聚合物多孔膜的制备.所形成的多孔膜具有良好的耐温性能和疏水拒油性,其对水接触角介于98°~116°之间,对正十二烷的接触角则介于43°~66°之间.     

双(环戊二烯基)二氯化锆催化合成乙烯-笼型倍半硅氧烷杂化共聚物及其结构表征

通过双(环戊二烯基)二氯化锆(Cp₂ZrCl₂)催化剂和改良的甲基铝氧烷(MMAO)助催化剂, 合成了无机-有机杂化共聚物. 研究了2种具有不同单乙烯基反应基团的笼型倍半硅氧烷(POSS)与乙烯的聚合. 对共聚产物的结构、 热力学性质、 分子量及其分布等进行了研究. 共聚单体(POSS)的插入率在0.01%~0.30%之间, 随着共聚单体在共聚物中摩尔分数的增大, 聚合物的熔点和熔解热降低. 共聚物的热重分析结果显示, 乙烯-POSS共聚物拥有更高的热分解温度以及较高的热分解残留量. 随着POSS的加入, 聚合物的分子量明显提高, 聚合物的分子量分布变宽.     

反应型POSS杂化纳米材料合成及其对聚合物的改性研究进展

多面体低聚笼型倍半硅氧烷(POSS)是一类分子内有机-无机杂化材料。该材料因为同时含有笼型的Si—O—Si核及键合在Si顶点上可设计的有机基团,所以兼具无机材料高的强度和耐温性以及有机基团灵活的可设计性,可广泛用于聚合物的改性。反应型POSS是指POSS上的有机基团与其改性聚合物有较高的反应活性,可以共价键合于聚合物分子链上,提高POSS在聚合物基体中的分散性,增强其界面粘接作用,更大程度提高聚合物的性能。本文综述了近年来反应型POSS的合成,POSS在聚合物增韧补强、耐热阻燃性能、介电性能改性等领域的研究进展,总结了POSS改善无机纳米粒子在聚合物改性体系分散性能方面的研究进展,并指出了今后的发展方向。     

Inorganic-Organic Hybrid Polymers Based on Surface-Modified Metal Oxide Clusters

Transition metal oxide clusters with unsaturated carboxylate ligands bonded to their surface were polymerized in the presence of organic co-monomers by various polymerization techniques to form cluster-reinforced polymers. The properties of the cluster-crosslinked hybrid polymers are distinctly different to those of the parent polymers and originate from both crosslinking and filler effects. Variation of the cluster proportion, the kind of employed cluster, the ratio of functional and non-functional capping ligands and the polymerization conditions allows modifying the materials properties of the hybrid materials. The most important changes in materials properties compared with the cluster-free polymers relate to the swelling behavior, thermal stability and mechanical properties. Furthermore, cluster-specific properties can be introduced into the polymers, such as magnetic properties.     

Recent advances in the preparation of hybrid nanoparticles in miniemulsions

In this review, we summarize recent advances in the synthesis of hybrid nanoparticles in miniemulsions since 2009. These hybrid nanoparticles include organic–inorganic, polymeric, and natural macromolecule/synthetic polymer hybrid nanoparticles. They may be prepared through encapsulation of inorganic components or natural macromolecules by miniemulsion (co)polymerization, simultaneous polymerization of vinyl monomers and vinyl-containing inorganic precursors, precipitation of preformed polymers in the presence of inorganic constituents through solvent displacement techniques, and grafting polymerization onto, from or through natural macromolecules. Characterization, properties, and applications of hybrid nanoparticles are also discussed.     

主链掺杂氧原子聚硅烷的研究进展

介绍了一类新型有机硅聚合物主链掺杂氧原子聚硅烷的合成与性质.该类聚合物是通过氧原子有规律地插入聚硅烷主链,形成具有氧杂低聚硅烷的序列结构(-[(SiMe2)mO]n-).聚合物的主链呈现了聚硅烷以及聚硅氧烷的杂化体结构.通过对此类聚合物性质的研究,能够获得有关此类聚合物行为的知识,从而进一步促进人们对聚硅烷和聚硅氧烷化学性质的了解.总结了此类聚合物的两类有效合成方法:通过α,ω-二功能基封端的线性硅烷低聚体缩聚反应法以及氧杂环硅烷单体的开环聚合反应法,包括氧杂环硅烷单体的开环聚合平衡和反应机理.讨论了此类聚合物的表征、热稳定性及其结构形态.在结论部分展望了此类聚合物的预期应用前景.     

Preparation and Characterization of PMMA/MMT Organic-Inorganic Hybrid Materials via RAFT Polymerization

In this article, the poly(methyl methacrylate)/montmorillonite (PMMA/MMT) organic-inorganic hybrid materials were prepared by conventional free radical polymerization and reversible addition-fragmentation chain transfer (RAFT) polymerization, respectively. The kinetics comparison of these two polymerizations was studied. The PMMA/MMT hybrid materials were characterized by gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). According to these results, we knew that the polymerization behavior of MMA showed controlled/living radical polymerization (CLRP) characteristics under the control of RAFT agent. The incorporation of RAFT agent and MMT nanoparticles improved the thermal properties of polymers, and the thermal stability of polymers increased with increasing content of MMT nanoparticles. The structures and morphologies of PMMA/MMT hybrid materials were characterized by FT-IR, XRD and TEM. These results showed that the MMA monomer can be initiated and propagated in the clay layers of MMT via the control of RAFT agent, and then the exfoliated structure was obtained for the hybrid materials.     

Hybrid π-conjugated polymers from dibenzo pentacyclic centers:precursor design,electrosynthesis and electrochromics

π-Conjugated polymers(CPs)represent one of the quite important and rapidly growing branches of flexible electrochromic materials.Electrosynthesized hybrid CPs employing dibenzo pentacycles(fluorenes,carbazoles,dibenzothiophenes,and dibenzofuran)as the backbones have received considerable attention owing to their special structures and interesting electrochromic performances.Recent studies show that polymers from these structures exhibit decent contrast ratios,favorable coloration efficiencies,low switching voltages,fast response time,excellent stability,and color persistence.Intrinsically,their electrochromic properties significantly depend on fine-tailoring of precursor monomer structures,and polymerization techniques and conditions.This review devotes to showing a clear picture of the research progress of dibenzo pentacycle-centered CPs via electrochemical polymerization,including fluorenes,carbazoles,dibenzothiophenes,and dibenzofuran-based hybrid electrochromic polymers.Critical influences of the tailored precursor structures on their electropolymerization and resultant polymer performances are highlighted,aiming at providing an insight for the development of novel fused ring-based polymer electrochromic materials.     

Twin Polymerization—a New Principle for Hybrid Material Synthesis

Twin polymerization is a novel modular approach for the synthesis of hybrid materials. Using this strategy two distinct polymers of either inorganic or organic nature are produced from a single source monomer in a mechanistically coupled process. Twin polymerization is an elegant way for producing nanostructured organic‐inorganic hybrid materials of composition and morphology on demand. The main objective of this Review is the explanation of the principle of various twin polymerization processes and their appropriate terminologies. Different types of twin polymerization are classified with respect to the underlying processes as described in individual examples, demonstrating its potential in material synthesis. Prospects of the synthetic methodology of twin polymerization are demonstrated for different molecular structures of twin monomers and the resulting hybrid materials. A comparison with other scenarios for the synthesis of two different polymers within one procedure is included.

     

六甲氧基甲基三聚氰胺-多元醇-丙烯酸酯混杂聚合体系的研究

六甲氧基甲基三聚氰胺 (HMMM) 多元醇 丙烯酸酯 酸催化剂混杂聚合体系在高温下同时进行缩聚和自由基聚合并表现出协同效应 .体系中的活泼亚甲基在HMMM的催化下被空气氧化成过氧化氢物 ;过氧化氢物在酸催化下分解成自由基进而引发自由基聚合反应 .研究结果表明 ,体系中存在固化加速的协同效应 ;同时体系中还存在热互补效应 ,丙烯酸酯的自由基聚合反应放出的热可以传递给缩聚反应 ,满足缩聚反应吸热的要求 .混杂聚合得到的高分子合金膜具有优良的机械性能和耐溶剂性能 ,这是由于在混杂聚合过程中形成了互穿聚合物网络 (IPN)结构 .使用潜酸催化剂作为酸的来源 ,可以提高体系的储存稳定性 ;交联 引发剂的使用可以拓宽它的使用范围 ;对超枝化聚合物在混杂体系中的应用也进行了初步研究     

Polymer Sol-Gel Synthesis of Hybrid Nanocomposites

The current state and main problems of polymer sol-gel synthesis as a method of the preparation of hybrid polymer-inorganic nanocomposites are analyzed. The general characterization of sol-gel reactions is given and the routes of the combination of sol-gel synthesis with the polymerization of traditional monomers are considered. Particular attention is given to the formation of sol-gel precursors in the presence of organic polymers, including the formation of interpenetrating hybrid networks. The specificity of hybrid nanocomposites based on multicomponent ceramics is discussed. The sol-gel process is analyzed as a promising route for the preparation of bioceramics in the presence of templates.     

Horseradish peroxidase‐based hybrid nanoflowers with enhanced catalytical activities for polymerization reactions of phenol derivatives

Catalytic activity and stability of HRP‐Cu²⁺ hybrid nanoflowers (hCu‐NFs) in the polymerization reactions of phenol derivatives was investigated. It was observed that the catalytic activity and stability of hybrid nanoflowers on the polymerization of the phenol derivatives was considerably higher compared to free Horseradish peroxidase (HRP) enzyme. The hCu‐NFs effectively polymerized phenolic compounds as a novel nanobiocatalyst and led to polymers having quite high yields, molecular weights, and thermal stabilities compared to free HRP enzyme. The hCu‐NFs provide substantial repeated use and showed some degree of catalytic activity even after fourth cycle experiment in the polymerization reactions.     

Polymethacrylate monolithic and hybrid particle-monolithic columns for reversed-phase and hydrophilic interaction capillary liquid chromatography

We prepared hybrid particle-monolithic polymethacrylate columns for micro-HPLC by in situ polymerization in fused silica capillaries pre-packed with 3–5 μm C₁₈ and aminopropyl silica bonded particles, using polymerization mixtures based on laurylmethacrylate–ethylene dimethacrylate (co)polymers for the reversed-phase (RP) mode and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl) zwitterionic (co)polymers for the hydrophilic interaction (HILIC) mode. The hybrid particle-monolithic columns showed reduced porosity and hold-up volumes, approximately 2–2.5 times lower in comparison to the pure monolithic columns prepared in the whole volume of empty capillaries. The elution volumes of sample compounds are also generally lower in comparison to packed or pure monolithic columns. The efficiency and permeability of the hybrid columns are intermediate in between the properties of the reference pure monolithic and particle-packed columns. The chemistries of the embedded solid particles and of the interparticle monolithic moiety in the hybrid capillary columns contribute to the retention to various degrees, affecting the selectivity of separation. Some hybrid columns provided improved separations of proteins in comparison to the reference particle-packed columns in the reversed-phase mode. Zwitterionic hybrid particle-monolithic columns show dual mode retention HILIC/RP behaviour depending on the composition of the mobile phase and allow separations of polar compounds such as phenolic acids in the HILIC mode at lower concentrations of acetonitrile and, often in shorter analysis time in comparison to particle-packed and full-volume monolithic columns.