利用主客体识别构建的树状超分子

树枝状大分子具有高度支化和规整的特殊结构,在生物医药、催化化学等多个领域深具发展前景,但目前其制备均采用化学合成方法。文中发展了一种利用自组装手段构筑树枝状大分子的新方法。通过中心分子4臂-聚乙二醇-金刚烷(4 arm-PEG-Ad)和迭代单元β-环糊精-肉桂(β-CD-Ci)以及α-环糊精-己二胺-金刚烷(α-CD-hex-Ad)之间的主客体识别,在水体系中,逐步组装得到超分子树状聚合物。通过动态光散射及透射电镜发现,随着代数增长,超分子树状聚合物在溶液中粒径逐渐变大。由于环糊精与客体基团可响应温度变化产生解包合,这种树状超分子结构在温度上升到60℃以上时会发生瓦解,超分子树状聚合物的粒径由最初的单分散性变为多分散性。     

含芘的超支化介孔聚合物的合成及对硝基芳烃的荧光传感性能

合成了以金刚烷为核心,以二苯乙炔基芘为连接臂的超支化聚合物P。金刚烷的三维立体结构及分子骨架的刚性结构特点,赋予了聚合物多孔的结构特点。研究结果表明,聚合物P具有均匀的狭缝孔道结构,其孔径多分布在10 nm左右,属于介孔材料。此外还合成了共聚单体二苯乙炔基芘(M)用于对比研究其光学性质及对硝基芳烃的荧光猝灭性能。聚合物P与单体M相比具有更大的Stokes位移,二者在含有三硝基甲苯(TNT)的溶液中,其平衡时的猝灭率几乎相同。然而二者在相同条件下制备的旋涂膜在二硝基甲苯(DNT)饱和蒸汽中,当达到猝灭平衡时,聚合物P的猝灭率为82%,而化合物M的猝灭率仅为22%。说明聚合物P多孔的特点使其透气性大大提高。以不同浓度的聚合物溶液制备出一系列厚度不同的薄膜,发现随着薄膜厚度的增加,荧光峰发生红移,但在DNT饱和蒸汽中的猝灭率变化不大。这种介孔的结构特点在一定程度上克服了旋涂膜传感器的猝灭率对厚度的依赖性。     

用途广泛的精细化工新原料──金刚烷

本文介绍了金刚烷的结构、性质、用途及其制备方法     

含金刚烷结构胺类固化剂的制备与性能

以1,3-二溴金刚烷为原料,合成了一种环氧树脂固化剂1,3-二[4-(4-氨基苯氧基)苯基]金刚烷(BAPPA),并采用傅里叶变换红外光谱、核磁共振波谱等对其结构进行了表征,用差示扫描量热分析研究了环氧树脂(E51)/BAPPA体系的固化反应动力学,根据Kissinger方程计算出体系的反应活化能为43.57kJ/mol。对E51/BAPPA固化物的耐湿热性能、动态热机械性能、力学性能、介电性能的表征结果表明,环氧树脂固化物的拉伸强度为98MPa,玻璃化转变温度(Tg)为176.3℃,Td5高达406℃,吸水率、介电常数比相同条件下E51/DDM固化物分别降低了34.9%和15.7%。     

温度响应的主客体超分子人工硒酶构建及催化机制研究

基于环糊精/金刚烷主客体作用制备了催化活力具有温度响应的超分子仿生硒酶(PNIPAM-CD-Te)。研究表明,PNIPAM-CD-Te的催化活力在25~45℃温度区间内具有典型的温度响应特性,37℃时具有最高催化活力(υ0=4.97mmol·L-1·min-1);同时,PNIPAM-CD-Te还展现出典型的酶催化饱和动力学行为。此外,研究表明,PNIPAM-CD-Te聚合物骨架在温度响应过程中会发生自组装结构的变化,这一变化对调控PNIPAM-CD-Te的底物结合能力具有重要作用,是导致PNIPAM-CD-Te催化活力具有温度响应特性的根本原因。     

金刚烷的应用开发

综述了近年来金刚烷化学领域的研究进展 ,讨论了其在合成及改性高聚物方面的应用。     

金刚烷基磺酸盐阻燃剂的制备及在聚碳酸酯中的应用

以1-溴金刚烷为原料,与苯发生傅克酰基化反应制得1,3,5,7-四苯基金刚烷,再与氯磺酸磺化制得1,3,5,7-四(苯基-4-磺酰氯)金刚烷,最后经过水解和中和反应制得目标产物1,3,5,7-四(苯基-4-磺酸钠)金刚烷阻燃剂(FR-A)。所有化合物均经傅里叶变换红外光谱、核磁共振、元素分析确证。将FR-A与聚碳酸酯(PC)共混,通过氧指数法和垂直燃烧测试法(UL94)测试了其阻燃性能,采用热重分析研究其热降解行为。结果表明,FR-A加入量为0.08%(质量分数)时,其阻燃效果明显提高,并且通过UL-94 V-0级实验。结合热重分析和差示扫描量热数据分析,添加阻燃剂后质量损失的起始温度和最大质量损失速率峰的发生温度均有所提高,产热量减少,具有较好的阻燃性能。     

金刚烷衍生物的晶体密度预测方法筛选

金刚烷类化合物稳定性高、密度大，是高能量密度化合物（HEDC）的理想目标物。采用密度泛函理论（B3LYP、M06-2X和B3PW91）结合5种基组（6-31G、6-31G*、6-31G**、6-311G*和6-31+G**），对15种已知实验密度ρ_e的金刚烷类化合物进行研究，以探寻适用于预测新型金刚烷类化合物晶体密度的方法。通过Monte-Carlo统计方法求得分子平均摩尔体积V，得到理论密度ρ_c，并与ρ_e相比较发现:3种密度泛函理论方法结合5种基组的平均绝对偏差均较小（0.04～0.07 g/cm³）;且ρ_c与ρ_e存在良好的线性关系,相关系数均大于0.98，标准偏差均小于0.05。建议使用M06-2X/6-31G*方法快速、准确地预测金刚烷类化合物的晶体密度。     

国外有机硅材料研发动态

概述了国外有机硅材料最新研发动态.着重介绍了与电子工业、燃料电池有关的含硅材料和以含硅的聚酰亚胺、聚硅倍半氧烷为基础的材料,以及聚二茂铁硅烷和金刚烷为基础的有机硅氧烷等的性能和应用.     

乳液聚合法制备纳米ZnO/聚合物复合材料的研究进展

纳米ZnO/聚合物复合材料结合了纳米ZnO优异的物理化学性能和聚合物易加工、高强度的特点,可广泛应用在电子、环保、化工、生物工程等领域。乳液聚合法因工艺简单、安全,条件温和,成本低等优点被广泛用于制备纳米ZnO/聚合物复合材料。对乳液聚合法制备纳米ZnO/聚合物复合材料的研究现状进行了综述。首先阐述了制备纳米ZnO/聚合物复合材料的乳液聚合方法,并对各种方法进行比较;然后归纳了纳米ZnO/聚合物复合材料的形成机理,并对纳米ZnO/聚合物复合材料在光电、抗紫外与抗菌、涂料等方面的应用现状进行了总结;最后,提出了纳米ZnO/聚合物复合材料未来的发展方向。     

Synthesis of Ionic Ultramicroporous Polymers for Selective Separation of Acetylene from Ethylene

The design of highly stable and efficient porous materials is essential for developing breakthrough hydrocarbon separation methods based on physisorption to replace currently used energy-intensive distillation/absorption technologies. Efforts to develop advanced porous materials such as zeolites, coordination frameworks, and organic polymers have met with limited success. Here, a new class of ionic ultramicroporous polymers (IUPs) with high-density inorganic anions and narrowly distributed ultramicroporosity is reported, which are synthesized by a facile free-radical polymerization using branched and amphiphilic ionic compounds as reactive monomers. A covalent and ionic dual-crosslinking strategy is proposed to manipulate the pore structure of amorphous polymers at the ultramicroporous scale. The IUPs exhibit exceptional selectivity (286.1–474.4) for separating acetylene from ethylene along with high thermal and water stability, collaboratively demonstrated by gas adsorption isotherms and experimental breakthrough curves. Modeling studies unveil the specific binding sites for acetylene capture as well as the interconnected ultramicroporosity for size sieving. The porosity-engineering protocol used in this work can also be extended to the design of other ultramicroporous materials for the challenging separation of other key gas constituents.     

窄带隙聚吡咯甲烷衍生物的制备与光学性能

由于高分子发光材料具有柔韧性好、合成简单、可大面积制备和使用寿命长等优点,成为近年来显示和照明领域的研究热点。本文以N-甲基吡咯和苯甲醛类为单体,采用缩聚法制备了3种可溶性、窄带隙、分子主链为部分共轭的聚吡咯甲烷衍生物,并利用红外光谱、紫外-可见光谱、荧光光谱、X射线衍射谱和热失重分析等方法对其结构、光致发光性质和热稳定性能等进行了测试分析,比较了大分子链上苯环对位取代基对材料发光性能的影响。研究结果表明,3种衍生物的热稳定性较好且具有部分结晶性,其光学禁带宽度均小于1.6 eV,属于窄带隙聚合物;在355 nm左右激发光下,3种衍生物均会产生约420 nm的发射光,为蓝紫色发光材料,且大分子链上苯环的对位取代基对该类材料的发光行为基本没有影响;在循环伏安曲线中,3种衍生物均存在较为明显的氧化还原峰。聚吡咯甲烷衍生物在光电器件材料方面有着潜在的应用价值。     

聚苯并咪唑树脂的合成与性能

聚苯并咪唑因其具有耐高温、耐腐蚀、阻燃、以及良好的力学性能、介电性能等多种优异性能而备受关注。我们合成了数种未见报道的新型聚苯并咪唑树脂,并用FT-IR、TGA、DSC进行了表征。在研究中我们对四胺合成路线进行了优化,改进了水解以及还原反应。实验以4,4’-二氨基联苯和邻硝基苯胺为原料合成了3,3’-二氨基联苯胺、3,3’,4,4’-四氨基二苯甲烷两种单体,通过两种单体与多种二元羧酸进行聚合制备了两个系列的聚苯并咪唑,在这些聚合物中我们选取了12种聚合物对它们的溶解性、耐热性进行了深入研究,多种数据显示这两类聚合物具有非常优异的热稳定性。     

降冰片烯及其衍生物开环易位聚合的研究进展

环烯烃开环易位聚合(ROMP)是指在金属催化剂存在下,环烯烃中的碳碳双键断裂并重新结合形成新的分子,得到的聚合物中留有不饱和双键,具有活性聚合的特点。ROMP是改造碳碳双键最有效的手段之一,极具特色且广泛应用于高分子材料与有机分子的合成。关于环烯烃ROMP研究早在20世纪50年代就已开始,当时的研究主要集中在以Ti、Re、W、Mo等过渡金属配合物组成的Ziegler-Natta催化体系引发环烯烃ROMP。20世纪80年代中期以后,研究则以亚烷基类或卡宾型类催化剂为主,其引发环烯烃ROMP的机理更加清晰。随着结构明确、稳定高效的环烯烃ROMP催化剂的开发与完善,该领域的研究焦点开始转向环烯烃ROMP适用单体的拓展以及所得聚合物的应用。在环烯烃ROMP研究中,降冰片烯及其衍生物是研究最多和应用最广的一类单体,这是因为它们的反应活性较高,来源丰富,价格也不昂贵。除研究拓展ROMP适用单体外,研究者主要从降冰片烯基单体的空间位阻、化学构型、侧基极性以及与其他环烯烃或降冰片烯基单体共聚改性等方面不断进行尝试,同时充分发挥环烯烃ROMP优势,与其他聚合方法联用,不断改善所得聚合物的性能并将其应用于不同研究领域。降冰片烯及其衍生物ROMP在阻燃材料、交换膜、纳米材料、生物医药等领域已取得一系列研究成果,其中在阻燃材料领域研究最早且许多产品已经工业化。在交换膜领域,由于降冰片烯基聚合物膜的热稳定性、耐酸碱性和电导率均较好,目前的研究主要是探索如何在燃料电池中获得应用。纳米材料是近年来最热门的研究领域之一,降冰片烯基纳米金属聚合物材料和纳米磁性聚合物材料等已有初步应用。在生物医药领域,降冰片烯及其衍生物极具发展前景,目前的研究主要集中在药物传输材料,已有初步的研究成果,但要实现工业化尚待进一步研究。此外,基于降冰片烯及其衍生物的接枝聚合物、嵌段聚合物、液晶聚合物、导电聚合物等也获得人们越来越多的关注。本文简要介绍了降冰片烯及其衍生物ROMP的反应机理,以及ROMP催化剂从多组分到钼、钨系再到钌系等几个发展阶段,详细综述了降冰片烯及其衍生物ROMP在上述若干领域的研究进展,并在此基础上简要探讨了今后研究与开发应用的新方向。     

光交联型液晶光控取向材料

液晶光控取向材料是近年来国际上的一个研究热点,其中光交联型材料因其稳定性强、取向效果好等优点被广泛研究。文中综述了肉桂酸酯类、香豆素类、苯乙烯基吡啶类、苯乙烯基苯并吡咯酮类、二苯基乙炔类光交联型液晶光控取向材料的研究进展,并对其光化学反应机理进行了分析。     

Investigation of the optical properties of polyfluorene/ZnO nanocomposites

Polyfluorene (PF) and its derivatives are very promising candidates for organic light emitting diodes (OLEDs) in lighting applications because of their high photoluminescence and electroluminescence efficiencies. Recent investigations of potential materials for OLEDs have shown that introducing n-type inorganic nanoparticles into conjugated polymers is efficient to produce stable and high performance devices. In this study, composite thin films made by incorporation of zinc oxide (ZnO) nanoparticles into a PF derivative have been prepared and their optical properties have been investigated.The prepared thin films were stored in different media (in air, in vacuum, in the dark or exposed to light) in order to study environmental influences on the material stability. Analysis of spectral data obtained from infrared (IR), Raman, UV-vis, and photoluminescence (PL) measurements shows a large enhancement in luminescence for polymer nanocomposites while using high nanoparticle concentrations (within a limit of 10% ZnO). Time-resolved PL performed on those nanocomposite films corroborated the above result: it indicated that the light-emission enhancement can be explained by efficient energy transfer from nanoparticles to the polymer chains and increase of the chain separation distance. In addition, the nanocomposites were found to be more stable than pristine polymer films whatever the storage conditions were used. It was confirmed by IR analysis that incorporation of nanoparticles into polymers prohibited the formation of fluorenonyl groups in PF chains, which was identified as the main cause of the degradation of the polymer under photo-oxidation.     

Polymer-coated fibrous materials as the stationary phase in packed capillary gas chromatography

Synthetic polymer filaments have been introduced as the support material in packed capillary gas chromatography (GC). The filaments of the heat-resistant polymers, Zylon, Kevlar, Nomex, and Technora, were longitudinally packed into a short fused-silica capillary, followed by the conventional coating process for open-tubular GC columns. The separation of several test mixtures such as n-alkylbenzenes and n-alkanes was carried out with these polymer-coated fiber-packed capillary columns. With the coating by various polymeric materials on the surface of these filaments, the retentivity was significantly improved over the parent fiber-packed column (without polymer coating) as well as a conventional open-tubular capillary of the same length. The results demonstrated a good combination of Zylon as the support and poly(dimethylsiloxane)-based materials as the coating liquid-phase for the successful GC separation of n-alkanes and polycyclic aromatic hydrocarbons (PAHs), while successful applications for other separations such as poly(ethylene glycol) coating for the separation of alcohols were also obtained. From the results it has been suggested that the selectivity of the fiber-packed column could be tuned by selecting different coating materials, indicating the promising possibility for a novel usage of fine fibrous polymers as the support material that can be combined with newly synthesized coating materials specially designed for particular separations. Taking advantage of good thermal stability of the fibers, the column temperature could be elevated to higher than 350 degrees C with the combination of a short metallic capillary.     

Ordered nanoporous polymer-carbon composites

Nanostructured organic materials, particularly those constructed with uniform nanopores, have been sought for a long time in materials science. There have been many successful reports on the synthesis of nanostructured organic materials using the so-called, 'supramolecular liquid crystal templating' route. Ordered nanoporous polymeric materials can also be synthesized through a polymerization route using colloidal or mesoporous silica templates. The organic pore structures constructed by these approaches, however, are lower in mechanical strength and resistance to chemical treatments than nanoporous inorganic, silica and carbon materials. Moreover, the synthesis of the organic materials is yet of limited success in the variation of pore sizes and structures, whereas a rich variety of hexagonal and cubic structures is available with tunable pore diameters in the case of the inorganic materials. Here we describe a synthesis strategy towards ordered nanoporous organic polymers, using mesoporous carbon as the retaining framework. The polymer-carbon composite nanoporous materials exhibit the same chemical properties of the organic polymers, whereas the stability of the pores against mechanical compression, thermal and chemical treatments is greatly enhanced. The synthesis strategy can be extended to various compositions of hydrophilic and hydrophobic organic polymers, with various pore diameters, connectivity and shapes. The resultant materials exhibiting surface properties of the polymers, as well as the electric conductivity of the carbon framework, could provide new possibilities for advanced applications. Furthermore, the synthesis strategy can be extended to other inorganic supports such as mesoporous silicas.     

具有光学活性的3,5-二(烷基羰基-胆固醇)苯乙烯螺旋聚合物的奇偶效应

根据胆固醇含多个手性中心,将其引入到聚苯乙烯的侧链中,合成了一系列侧基含有手性链胆固醇基团的螺旋聚合物。这些无定形聚合物都有良好的热稳定性,随着柔性链上碳原子个数的增加,玻璃化转变温度逐渐降低。表征发现所有聚合物都为手性的螺旋结构聚合物,且随着柔性链的增长,所有的CD图上的科顿效应转变为同时含有正负科顿效应,最后转变为几乎只含有负科顿效应的现象,证明了手性胆固醇上的柔性链对聚合物分子的螺旋排列有着较大的影响。     

纳米SiO2改性聚酰亚胺的研究进展

聚酰亚胺(PI)作为一种功能材料,具有良好的介电性、优良力学性能,已被广泛应用于航空航天及微电子领域,但其明显的吸水性和热膨胀性限制了其在高温和精密状态下的应用。纳米SiO2具有很低的热膨胀系数和较低的吸水性,非常适合于对PI的改性。介绍了纳米SiO2的生产原理、纳米SiO2／PI复合材料的制备方法、性能及其在气体分离膜、光电材料、摩擦材料及包装材料方面的应用,并对这类材料的研究方向提出了自己的建议。