聚(N–芳基化苯并咪唑酮)的合成与热性能研究

以酮基双苯并咪唑和4,4'–二氟二苯甲酮为单体,通过亲核取代反应得到聚(N–芳基化聚苯并咪唑酮)。通过N–芳基化的方法把苯并咪唑和酮基引入到聚合物主链中,以期得到一类耐热性能优异的含酮基聚苯并咪唑。通过分子模拟方法对目标聚合物的分子链结构及其堆积状态进行了计算分析,其结构通过FT–IR、1H–NMR和元素分析表征。该聚合物由于具有较为刚性的分子骨架结构,故表现出优异的热性能和较高的玻璃化转变温度(T5%=501℃,Tg=279℃)。     

含苯并咪唑低热胀聚酰亚胺的合成及性能

以2-(4-氨基苯基)-5-氨基苯并咪唑(PABZ)、对苯二胺(PDA)、3,3’,4,4’-联苯四羧酸二酐(BPDA)为原料成功制备了一系列含苯并咪唑的高耐热低热胀聚酰亚胺(PI),并表征了其结构和性能。红外吸收光谱表明聚合物已经亚胺化;X射线衍射表明PABZ的摩尔分数超过5%的聚酰亚胺分子链之间的距离更窄,含20%PABZ的聚合物d间距仅为0.425nm;热重分析表明随着PABZ的加入,1%的失重温度从565℃降低到532℃;热机械分析表明材料线膨胀系数呈先增大再减小的趋势,随着分子链中苯并咪唑含量的增加,线膨胀系数从10.2×10^-6K^-1下降到2.7×10^-6K^-1。通过分子模拟表明:苯并咪唑中的—NH—可以与酰亚胺环的C=O产生氢键,导致分子链之间的间距更小,自由体积分数更小,相互之间作用力更大,拥有更低的线膨胀系数。力学性能测试表明,苯并咪唑的引入,薄膜的拉伸强度和模量小幅上升,断裂伸长率稍微下降。     

耐热400℃的硅氧烷弹性体

最近,在美帝空军材料实验室的资助下,报导了一种耐温400℃的硅氧烷弹性体,叫做聚二甲基硅氧烷——苯并眯唑聚合物。在分子主链上每35个二甲基硅氧烷单元和一个苯并咪唑单元相连,分子式如下所示:     

N芳基化聚苯并咪唑泡沫的制备与性能

以含甲基的双苯并咪唑和二氟二苯砜为单体,通过N–芳基化反应得到了一种新型的聚芳醚苯并咪唑。以聚芳醚苯并咪唑/1,4–二氧六环为聚合物溶液体系,通过热致相分离法和冷冻干燥技术成功制备了系列低密度（0.10~0.35 g/cm聚芳醚苯并咪唑泡沫材料。该泡沫材料具有优异的热稳定性和较高的玻璃化转变温度。另外,通过对聚合物泡沫材料力学性能的测试可知,该聚芳醚苯并咪唑泡沫材料具有较好的力学性能。     

液晶高分子新型材料：Ⅱ 液晶高分子的合成

1 液晶基元、连接基团和液晶单元合成的任务在于先用适当的聚合方法将小分子的液晶基元通过刚性连接基团连接成较大分子量的液晶单元,将这些液晶单元再通过刚性连接基团连接成刚性液晶大分子链或通过亚甲基连接基团连接成重复单元并进而聚合成为半刚性液晶性大分子链,最后由这些大分子链构成聚合物本体并赋予其液晶性。     

功能化聚芳醚酮固载铜离子抑菌膜制备及表征

为了使微孔滤膜具有抑菌功能，以自制的侧链含苯并咪唑结构聚芳醚酮为膜材料，利用苯并咪唑基团与Cu²⁺间的配位作用，通过非溶剂致相分离法(NIPS)和金属离子配位改性法制备抑菌型微孔滤膜。对固载Cu²⁺前后的微滤膜的微观结构、抗污性能、抑菌性能、耐溶剂性能以及膜的Cu²⁺固载量等进行测试与表征。结果表明，Cu²⁺能够被固载至含有苯并咪唑结构的微孔滤膜上。所制备的Cu²⁺螯合膜对大肠杆菌的抑制率可达63%，且随着开孔率的增加，膜的抑菌性能有所提升。其中，抑菌圈实验和Cu²⁺流失速率测试实验进一步说明了Cu²⁺与聚合物分子链上的苯并咪唑基团间的相互作用能够将Cu²⁺约束在膜内,有效缓解金属离子流失现象。     

耐高温高分子材料聚苯井咪唑

最近美国杜邦公司等单位,对新的高分子材料聚苯并咪唑(Polybenzimidazloes)作了不少研究。据说这种新的高分子材料对于宇宙飞行有重大意义。这种高分子化合物是以3,3′二氨基联苯胺与二苯基间苯二甲酸盐反应制成。聚合物中有联苯胺和苯并咪唑单元,分子量约90,000。由于高分子链中有高度的芳香性质,使这种聚合物具有耐高温的特点。这种聚合物可以纺丝。据说它的耐高温性质,在现有的合成纤维中是最好的。在840℉时,仍能保持     

基于聚集诱导发光效应的高固低黏丙烯酸荧光树脂的制备及其性能研究

为了研制一种具有荧光功能特性的高固低黏羟基丙烯酸树脂。从聚集诱导发光效应（AIE）出发,将具有 AIE性质的二对丙烯酸四苯乙烯酯荧光分子通过自由基共聚连接于聚合物链段。由于聚合物链段对荧光分子化学键固定以及聚合物链的包裹束缚作用,导致荧光分子运动受限,从而实现涂层在紫外灯下荧光发光。通过荧光光谱的实时跟踪,探索高固低黏羟基丙烯酸树脂的合成以及固化规律。此外,由于聚合物链段对外界刺激具有实时响应性,从而间接影响了所连接的荧光分子的荧光发光行为。因此,文中也探索了涂层在外界温度与化学气体的影响下所发生的荧光变化的规律,以探索其在功能涂层中应用的可行性。     

以PVA、淀粉和ENR为基础的“绿色”聚合物共混体的物理性能

互穿聚合物网络(IPN)是由两种以上聚合物组成的共混物,它通过永久的缠结连接形成网络结构,在两种不同的聚合物链之间形成一些随机的共价键。与单一组分聚合物相比,很多情况下IPN结构能提高物理性能。IPN结构可以使电子材料、膜材料、导电聚合物和其他用途的聚合物获     

双端三齿配体基La(Ⅲ)凝胶聚合物合成及性能研究

以1,6-二溴己烷和1,8-二溴辛烷与富含氮单体2,6-二苯并咪唑基-4-羟基吡啶反应制备双端三齿配体1,6-二-(2,6-(二苯并咪唑基)吡啶氧基)己烷和1,8-二-(2,6-(二苯并咪唑基)吡啶氧基)辛烷。两种配体分别与过渡金属离子La(Ⅲ)组装得到具有温度响应性和化学刺激响应的凝胶状聚合物,并具有一定的荧光效应。NMR表征表明成功的制备了单体及配体,应用TG、XRD对聚合物的性能进行测试。刺激响应性实验表明此凝胶聚合物对温度具有可逆的响应性,并对化学试剂甲酸具有化学刺激响应性。光学性能研究表明,在紫外线的照射下,聚合物具有明显的发光现象,最大发射峰都位于419 nm处。     

Molecular-scale hybrid membranes: Metal-oxo cluster crosslinked benzimidazole-linked polymer membranes for superior H2 purification

Hydrogen (H₂) purification requires separation membranes with excellent performance and high stability. Here, a few nanometer-sized Zr-oxygen clusters (CP-2) abundant in amino groups were incorporated in benzimidazole-linked polymers (BILPs) by interfacial polymerization (IP) to fabricate molecular-scale hybrid membranes for efficient H₂/CO₂ separation. The amino groups in CP-2 engage in IP. The structure of the BILPs polymer chains is regulated and more H₂ selective channels are created. The hybrid membranes provide an H₂/CO₂ selectivity of up to 75.2 (with a corresponding H₂ permeance of 318 GPU) and a high H₂ permeance of up to 1470 GPU (with a corresponding H₂/CO₂ selectivity of 23.6). In addition, the membranes exhibit satisfactory separation performance and durability under industry-relevant conditions (573 K, 11 bar, or steam treatment).     

Synthesis of high temperature polyaspartimide-urea based shape memory polymers

Thermally activated shape memory polymers (SMPs) have attracted great interest in recent years for application in adaptive shape-changing (morphing) aero structures. However, these components require materials with transition temperatures well above the glass transition temperatures of most widely available SMPs while also maintaining processability and property tailorability. In the present study, a series of novel polyaspartimide-urea based polymers are synthesized and characterized. The glass transition temperature and shape memory properties are varied using a diisocyanate resin creating a urea crosslinking moiety between the polyaspartimide chains. Overall, a family of high temperature SMPs was synthesized and characterized showing high thermal stability (>300 °C), toughness, strong shape memory effects, and tailorable properties.     

Elastomeric block polymers from ethylene sulphide

Block polymers of ethylene sulphide with butadiene, isoprene and styrene have been prepared by anionic synthesis, and their properties have been examined. The ABA polymers from ethylene sulphide and isoprene are elastomers with good thermal stability but unless of low molecular weight are difficult to process except at high temperatures, when they are prone to degradation. ABC block polymers from styrene, isoprene or butadiene and ethylene sulphide are strong resilient elastomers with improved thermal stability compared with the conventional styrene/butadiene block polymers. Good properties are obtained with small amounts (2–4%) of low molecular weight (～4000), highly crystalline poly(ethylene sulphide) blocks. X-ray, differential scanning calorimetry, and gel permeation chromatography data show the ethylene sulphide blocks to be anisotropic, extended-chain crystallites which aggregate large numbers of the attached diene/styrene chains. These aggregates persist at temperatures above the softening point of the polystyrene domains, and in solution. The polymers possess unusual flow characteristics which are not well understood. Electron micrographs of stained, cast or microtomed films show the elastomers to have a two-phase morphology. It has not been possible to identify the structure of the small poly(ethylene sulphide) domains. The ABC polymers can be oil extended and compounded with carbon black. Vulcanizates using accelerated sulphur systems have good physical properties.     

Heterocyclic polyimides containing siloxane groups in the main chain

BACKGROUND: Among the polymers widely studied for applications in advanced techniques, aromatic polyimides have received considerable attention due to their outstanding thermal stability associated with good electrical and mechanical properties. However, these polymers are usually difficult to process, being insoluble and without a glass transition. To improve the processing characteristics of polyimides, modification of their structure is often achieved by the introduction of flexible linkages in the macromolecular chain or various substituents on the aromatic rings. RESULTS: A series of polyimides and intermediate polyamidic acids were synthesized from aromatic oxadiazole‐diamines and a dianhydride containing a siloxane bridge (? R₂Si? O? SiR₂? ). These polymers exhibit good solubility in certain organic solvents and can be cast into thin and very thin films from their solutions. They exhibit high thermal stability with decomposition being above 440 °C and relatively low glass transition temperatures in the range 160–190 °C. These polymers show strong photoluminescence in the blue spectral region. CONCLUSION: The introduction of oxadiazole rings together with siloxane groups into the chains of aromatic polyimides gives highly thermostable polymers with remarkable solubility and film‐forming ability and that emit blue light, being attractive for applications in micro‐ and nanoelectronics and other related advanced fields. Copyright © 2009 Society of Chemical Industry     

Effect of different side chains on alternating copolymers of benzodithiophene and thiophene in organic solar cells

Polymeric semiconductors offer the dual advantages of lightness and flexibility, facilitating the large-scale production of organic electronic devices. In the present research, electron donor polymers were synthesized incorporating high electron density aromatic units, specifically benzodithiophene (BDT) and thiophene (Th), to explore their efficacy in organic electronics. This systematic study focused on evaluating the impact of varying side chains on the material properties of these polymers. It was found that polymers with Th side chains exhibited significantly enhanced thermal stability, approximately 100°C higher than their alkoxide side chain counterparts. For the polymer PEHO-BDT3HT, a bandgap value of around 1.6 eV was obtained. Furthermore, binary devices were developed using these novel copolymers, among which PDT-BDT3HT demonstrated superior photovoltaic performance, achieving a power conversion efficiency of 1.56% without any optimization. This work not only sheds light on the influence of side chain variations in polymer properties but also showcases the potential of BDT and Th-based copolymers in the field of organic electronics.     

High-energy mechanical alloying of thermoplastic polymers in carbon dioxide

High-energy ball milling was performed on low density polyethylene (LDPE) and isotactic polypropylene (iPP) as well as on 20/80 binary mixture of both polymers. Mechanical alloying was carried out at high pressure with carbon dioxide for a short period. The presence of CO₂ avoids oxidative mechano-chemical degradation of polymers and enhances the effectiveness of the milling. The effects of the mechano-chemical treatment on the molecular and physical properties of both single polymers and blends of intrinsically incompatible polymers were explored by FTIR spectroscopy, thermal analysis, intrinsic viscosity determination and solvent fractionation. Structural changes on PP and PP/LDPE blend were observed and have a strong dependence on the milling time. Mechanical tests confirm an overall improvement in blend properties by mechanical alloying. Experimental evidences are presented to suggest that CO₂ high-energy ball milling causes a self-compatibilization of the blend LDPE-iPP by breaking iPP polymer chains and allowing them to recombine with the neighboring LDPE chains.     

表面接枝二分散聚合物的自洽场理论

建立了表面接枝多分散聚合物的自洽场理论.通过对二分散聚合物进行自洽场模拟,研究了排除体积参数对分子链密度分布的影响,考察了分子链的摩尔分数与自由端分布的关系并将模拟结果与强伸展理论进行了比较.通过计算分子链的链段密度分布和伸展轨迹,讨论了二分散聚合物分子链的伸展行为.     

Supramolecular Polymers – we've Come Full Circle

Since the first polymers were discovered, scientists have debated their structures. Before Hermann Staudinger published the brilliant concept of macromolecules, polymer properties were generally believed to be based on the colloidal aggregation of small particles or molecules. From 1920 onwards, polymers and macromolecules are synonymous with each other; i. e. materials made by many covalent bonds connecting monomers in 2 or 3 dimensions. Although supramolecular interactions between macromolecular chains are evidently important, e. g. in nylons, it was unheard of to proposing polymeric materials based on the interaction of small molecules. Breakthroughs in supramolecular chemistry, however, showed that polymer materials can be made by small molecules using strong directional secondary interactions; the field of supramolecular polymers emerged. In a way, we have come full circle. In this essay we give a personal story about the birth of supramolecular polymers, with special emphasis on their structures, way of formation, and the dynamic nature of their bonding. The adaptivity of supramolecular polymers has become a major asset for novel applications, e. g. in the direction for the sustainable use of polymers, but also in biomedicine and electronics as well as self-healing materials. The lessons learned in the past years include aspects that forecast a bright future for the use of supramolecular interactions in polymer materials in general and for supramolecular polymers in particular. In order to give full tribute to Staudinger in the year celebrating 100 years of macromolecules, we will show that many of the concepts of macromolecular polymers apply to supramolecular polymers, with only one important difference with fascinating consequences: the dynamic nature of the bonds that form polymer chains.     

两亲性聚合物分子自组装的研究进展

两亲性聚合物以其同时具有亲水和疏水链段的独特结构,在生物医药、纳米技术等领域有广泛的用途。本文主要介绍了两亲性聚合物通过分子自组装形成聚集体的研究进展,详细论述了几种分子自组装聚集体的制备,包括结构、组成、分子量控制的简单聚集体、半结晶聚集体、交联聚集体以及具有刺激响应性（pH值响应性、温度响应性、pH值/温度双重响应性、氧化还原响应性、溶剂极性响应性等）的智能型聚集体,两亲性聚合物结构的可控性以及如何提高聚集体的稳定性成为国内外专家研究的重点,指出结晶诱导分子自组装及智能型分子自组装是未来研究的热点。     

Polymer Inclusion Compounds: Model Systems for Ordered Bulk Polymer Phases and Starting Materials for Fabricating Polymer–Polymer Molecular Composites

Several small molecules can be cocrystallized with polymers to form inclusion compounds (ICs). Urea, perhydrotriphenylene and the cyclodextrins are examples, and serve to form the host crystalline lattice containing the guest polymer chains in their ICs. The guest polymer chains are confined to narrow, cylindrical channels created by the host, small-molecule lattice, where the polymers are highly extended as a consequence of being squeezed, and are separated from neighbouring polymer chains by the IC channel walls composed exclusively of the small-molecule lattice. The net result is a unique solid-state environment for polymers residing in IC channels, which can be utilized as model systems for ordered, bulk polymer phases. Comparison of the behaviour of polymer chains isolated and extended in IC crystals with the behaviour observed for ordered, bulk phases of polymers is beginning to permit an assessment of contributions made by the inherent, single chain and the cooperative, interchain interactions to the properties of ordered, bulk polymers. It is also possible to release and coalesce polymers from their IC crystals in a manner which leads to their consolidation with a chain-extended morphology. Embedding polymer IC crystals into a carrier polymer, followed by in situ release and coalescence of the included polymers from their IC crystals, offers a means to obtain polymer–polymer composites with unique morphologies. Several such polymer IC-generated composites are described and it is suggested that their unique morphologies might translate into useful, tailorable properties, as well as providing a means for addressing several questions that are fundamental to the behaviour of both phase-separated and homogeneous polymer solids. © 1997 SCI