有序介孔聚合物的研究进展

综述了以自组装法、硬模板法和软模板法合成有序介孔聚合物及介孔碳的研究进展。对上述3种制备方法及原理进行了比较,指出目前以嵌段共聚物进行自组装以及采用软模板法制备介孔聚合物的途径更有利于制备有序的介孔聚合物及介孔碳。讨论了采用自组装法及软模板法时,嵌段共聚物的种类、模板剂的类型、聚合物前躯体的结构等对所制备的介孔聚合物以及介孔碳的形貌、介孔结构、骨架结构以及介孔材料的物理化学性能的影响。指出目前在介孔聚合物以及介孔碳的研究中,主要问题是如何提高介孔聚合物的有序性以及其介孔结构的稳定性。最后对有序介孔聚合物及介孔碳的发展方向及应用领域进行了展望。     

碳点/聚苯胺复合物的模板法制备与电化学性能研究

通过原子转移-自由基聚合反应(ATRP)合成了一种两亲性嵌段共聚物聚苯乙烯-聚丙烯酸(PS-b-PAA),通过核磁共振氢谱(~1H NMR)、凝胶渗透色谱(GPC)表征两亲性嵌段共聚物的结构。以嵌段共聚物PS-b-PAA为模板制备了具有均匀形貌的聚苯胺(PANI)和碳点/聚苯胺(CDs/PANI)复合颗粒。通过傅里叶变换红外(FTIR)、紫外-可见吸收光谱(UV-vis)表征聚合物结构。透射电镜(TEM)、马尔文粒度分析仪确定导电聚合物颗粒的形貌及尺寸分布。结果表明,制得了平均直径为264 nm的PANI纳米棒和平均粒径为350 nm的类五边形不规则CDs/PANI颗粒。通过循环伏安、计时电位、交流阻抗等电化学手段表征了材料的电容性能。认为材料具有较理想的赝电容行为和充放电能力,当电流密度为1 A/g时PANI和CDs/PANI的首次放电比容量分别达到626 F/g、1 320 F/g。     

以PEO-b-PtBA及PEO-b-PAA为模板制备聚联苯胺及其电化学性能研究

以两嵌段共聚物聚氧化乙烷-b-聚丙烯酸叔丁酯(PEO-b-Pt BA)及其水解产物聚氧化乙烷-b-聚丙烯酸(PEO-b-PAA)为模板制备了亚微米至纳米级棒状聚联苯胺(PBz)颗粒。利用红外光谱、核磁共振、透射电镜及循环伏安和交流阻抗等测试了PBz的结构、形貌和电化学性能。结果表明,嵌段共聚物为模板合成的PBz呈现棒状分布,颗粒直径均小于200 nm且部分在100 nm以内。PBz颗粒形貌均匀,尺寸均一,使用有机溶剂溶解嵌段共聚物模板未对PBz颗粒形貌产生影响。不同模板合成的PBz均具有一定的电化学活性,以PEO-b-PAA为模板得到的各样品电化学性能优于PEO-b-Pt BA为模板的情况。在电流密度为1 A/g时,材料比电容最高达到了263 F/g。     

纳米孔结构聚合物发泡材料的制备与性能研究进展

综述了近几年来具有纳米孔结构聚合物发泡材料的制备方法,主要包括嵌段共聚物、纳米复合材料和聚合物共混物发泡以及改进的传统制备方法,并对其独特的热学、力学、电学和光学性能进行介绍。最后,对其未来的发展方向进行了展望。随着研究的深入,纳孔发泡材料的制备工艺和性能将会进一步优化。     

聚合物纳孔发泡材料制备方法研究进展

综述了近年来聚合物纳孔发泡材料的制备方法,重点对嵌段共聚物和纳米级分散相聚合物共混物发泡法的原理及研究成果进行了介绍和总结,并对其研究方向进行了展望。     

有机硅-聚酰胺嵌段共聚物研究进展

综述了有机硅-聚酰胺嵌段共聚物制备及其结构-性能耦合关系的研究现状。分别采用大分子引发法可制备有机硅-聚酰胺二嵌段或三嵌段共聚物,以及聚合物-单体缩合或聚合物-聚合物缩合法可制备有机硅-聚酰胺多嵌段共聚物。分子量、组成和序列结构对有机硅-聚酰胺嵌段共聚物的微观相分离有显著影响,进而影响其宏观性能。加强对有机硅-聚酰胺嵌段共聚物"制备-结构-性质"关系的剖析,并寻找环境更友好的制备路线,将是今后研究的重点。     

不同SEBS结构与性能关系探究

高聚物的性能取决于结构。本文以两种苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)为研究对象,通过红外、核磁、差示扫描量热法和动态力学分析对其结构进行了剖析,并对其制备的大输液膜制品的形貌和性能进行了表征。结果表明,SEBS中硬段含量、软段成分及不饱和度都会对其制品性能产生影响。     

烯烃多嵌段共聚物的结构、合成及应用

烯烃多嵌段共聚物是一种新型的聚烯烃热塑性弹性体,主要通过催化乙烯和1-辛烯链穿梭聚合制备得到多嵌段含"软段"和"硬段"的聚合物,其独特结构和性能已经成为新材料的研究热点。本文概述了烯烃嵌段多共聚物的结构和制备合成,并指出了烯烃多嵌段共聚物性能和应用前景。     

微孔及纳米孔发泡材料研究进展

对聚合物微孔发泡基本过程、机理、聚合物微孔发泡的实施等进行了介绍,同时指出通过嵌段共聚物为载体可以制备纳米孔发泡材料。     

聚合物基纳米复合材料研究的进展

本文简单介绍了聚合物基纳米复合材料的类型,总结了聚合物基纳米复合材料的制备方法、所制备材料的性能及应用情况,并对纳米复合高聚物的发展前途进行了展望。     

Efficient synthesis of two or multi component block copolymers through living radical polymerization with polymeric photoiniferters

Summary To synthesize efficiently block copolymers, the radical polymerization of vinyl monomers with the polymers obtained by tetraethyl thiuram disulfide(TD) as polymeric photoiniferters has been investigated. These photopolymerizations were found to proceed via a living radical mechanism, i.e. both the whole polymer yields and the average molecular weight of the block copolymers increased with increasing of the polymerization time. By applying these living radical polymerizations, various block copolymers consisting of two, three and four component blocks were obtained in good yields, suggesting that these techniques are effective and useful for synthesizing multi component block copolymers through radical polymerizations of polar vinyl monomers.     

Synthesis and characterization of novel polystyrene‐block‐polyurethane‐block‐polystyrene tri‐block copolymers through atom transfer radical polymerization

Background: Radical polymerization is used widely to polymerize more than 70% of vinyl monomers in industry, but the control over molecular weight and end group of the resulting polymers is always a challenging task with this method. To prepare polymers with desired molecular weight and end groups, many controlled radical polymerization (CRP) ideas have been proposed over the last decade. Atom transfer radical polymerization (ATRP) is one of the successful CRP techniques. Using ATRP, there is no report on the synthesis of polystyrene‐block‐polyurethane‐block‐polystyrene (PSt‐b‐PU‐b‐PSt) tri‐block copolymers. Hence this paper describes the method of synthesizing these tri‐block copolymers. To accomplish this, first telechelic bromo‐terminated polyurethane was synthesized and used further to synthesize PSt‐b‐PU‐b‐PSt tri‐block copolymers using CuBr as a catalyst and N,N,N,N″,N″‐pentamethyldiethylenetriamine as a complexing agent. Results: The ‘living’ nature of the initiating system was confirmed by linear increase of number‐average molecular weight and conversion with time. A semi‐logarithmic kinetics plot shows that the concentration of propagating radical is steady. The results from nuclear magnetic resonance spectroscopy, gel permeation chromatography and differential scanning calorimetry show that the novel PSt‐b‐PU‐b‐PSt tri‐block copolymers were formed through the ATRP mechanism. Conclusion: For the first time, PSt‐b‐PU‐b‐PSt tri‐block copolymers were synthesized through ATRP. The advantage of this method is that the controlled incorporation of polystyrene block in polyurethane can be achieved by simply changing the polymerization time. Copyright © 2007 Society of Chemical Industry     

Synthesis and characterization of rubbery highly fluorinated siloxane–imide segmented copolymers

The synthesis and characterization of a series of poly(siloxane–imide) block (or segmented) copolymers obtained by copolymerization of amine‐terminated polydimethylsiloxane with fluorinated aromatic compounds containing anhydride and amine functionality are reported. New fluorinated block copolymers have been synthesized to obtain organophilic polyimides potentially interesting for molecular membrane separations. The new aspects of this work relative to the literature are (1) a comparison of solution and solid‐state approaches in the imidization step to generate the target poly(siloxane–imide) copolymers and (2) exploration of new compositions involving fluorinated aromatic polymers derived from added diamine compounds. It is shown that the copolymer properties can be tailored from glassy to rubbery materials by varying the amount and the type of oligosiloxane used; the transition between glassy and rubbery properties is characterized at a siloxane content of 60 wt%. As a main result, it is shown that the solid‐state approach for inducing the cyclo‐imidization step is the more efficient one for synthesizing polymers with good mechanical properties, when the amount of siloxane block is increased in the copolymer series. Physical and chemical methods (thermogravimetric analysis, Fourier transform infrared spectroscopy, viscosity measurements) were used to characterize the copolymer properties obtained according to the two different synthesis routes. The obtained siloxane–imide copolymers are well soluble in a large variety of moderately polar solvents and exhibit very good thermal stability up to 400 °C. Hence the prepared copolyimides would seem to be promising candidates as organophilic membranes as well as gas permeation membranes. © 2012 Society of Chemical Industry     

DNA block copolymers: functional materials for nanoscience and biomedicine

We live in a world full of synthetic materials, and the development of new technologies builds on the design and synthesis of new chemical structures, such as polymers. Synthetic macromolecules have changed the world and currently play a major role in all aspects of daily life. Due to their tailorable properties, these materials have fueled the invention of new techniques and goods, from the yogurt cup to the car seat belts. To fulfill the requirements of modern life, polymers and their composites have become increasingly complex. One strategy for altering polymer properties is to combine different polymer segments within one polymer, known as block copolymers. The microphase separation of the individual polymer components and the resulting formation of well defined nanosized domains provide a broad range of new materials with various properties. Block copolymers facilitated the development of innovative concepts in the fields of drug delivery, nanomedicine, organic electronics, and nanoscience. Block copolymers consist exclusively of organic polymers, but researchers are increasingly interested in materials that combine synthetic materials and biomacromolecules. Although many researchers have explored the combination of proteins with organic polymers, far fewer investigations have explored nucleic acid/polymer hybrids, known as DNA block copolymers (DBCs). DNA as a polymer block provides several advantages over other biopolymers. The availability of automated synthesis offers DNA segments with nucleotide precision, which facilitates the fabrication of hybrid materials with monodisperse biopolymer blocks. The directed functionalization of modified single-stranded DNA by Watson-Crick base-pairing is another key feature of DNA block copolymers. Furthermore, the appropriate selection of DNA sequence and organic polymer gives control over the material properties and their self-assembly into supramolecular structures. The introduction of a hydrophobic polymer into DBCs in aqueous solution leads to amphiphilic micellar structures with a hydrophobic polymer core and a DNA corona. In this Account, we discuss selected examples of recent developments in the synthesis, structure manipulation and applications of DBCs. We present achievements in synthesis of DBCs and their amplification based on molecular biology techniques. We also focus on concepts involving supramolecular assemblies and the change of morphological properties by mild stimuli. Finally, we discuss future applications of DBCs. DBC micelles have served as drug-delivery vehicles, as scaffolds for chemical reactions, and as templates for the self-assembly of virus capsids. In nanoelectronics, DNA polymer hybrids can facilitate size selection and directed deposition of single-walled carbon nanotubes in field effect transistor (FET) devices.     

Conducting Polymer Nanostructures and their Derivatives for Flexible Supercapacitors

This review provides a brief summary of the recent research developments in the fabrication and application of conducting polymer nanostructures and their derivatives as electrodes for flexible supercapacitors (SCs). By controlling the nucleation and growth process of polymerization, conducting polymers (CPs) with different nanostructures can be prepared by employing chemical polymerization, electrochemical polymerization and photo-induced polymerization. These CPs (such as polyaniline and polypyrrole) with special nanostructures possess high capacitance, superior rate capability ascribed to large electrochemical surface, and optimal ion diffusion path in the ordered nanostructures. The composites of nano-structured conducting polymer and some conductive flexible substrates (such as carbon nanotube film and graphene film) are proved to be ideal electrode materials for high performance flexible SCs. Furthermore, high N-containing CPs are very prospective for preparing N-doped carbon materials used as flexible electrodes for flexible SCs. With respect to the extra pseudo-capacitance induced by N atoms and superior stability derived from the conjugated graphitic structure of carbon materials, the obtained flexible SCs based on N-doped carbon materials could achieve high capacitance, high rate performance, and superior cycling stability.     

生物质模板剂制备介孔材料研究进展

介孔材料的制备通常采用模板法,所用模板剂多为石油衍生的表面活性剂,属于不可再生资源,这种模板剂的使用不符合可持续发展的理念。生物质模板剂具有原料来源广、毒性低、绿色环保等优点,因此受到了研究人员的广泛关注。本文综述了近年来国内外利用生物质模板剂制备介孔材料的研究进展,阐述了脂肪酸及其衍生物、氨基酸类、糖类、脂类等生物质衍生物作为模板剂应用于介孔材料制备的现状,其中糖类作为模板剂用于介孔材料的制备研究较多,简要介绍了利用不同种类生物质模板剂制备介孔材料的条件以及生物质模板剂的去除方法,得出生物质模板剂制备介孔材料操作简单、模板剂容易去除的结论,同时列表总结了所得介孔材料的结构及性质特点和应用情况,并对该领域的研究方向进行了展望。指出采用低成本的方法提纯生物质模板剂,绿色的方法去除生物质模板剂以及构建生物质模板剂的结构、组成与介孔材料的结构、性质之间的对应关系是未来发展的主要方向。     

Synthesis of amphiphilic PVC‐b‐poly(hydroxypropyl acrylate) (PHPA)‐b‐PVC block copolymers with low PHPA contents and different molecular weights by (Single Electron Transfer)—(Degenerative Chain Transfer) living radical polymerization

The aim of this work was to synthesize new amphiphilic block copolymers, based on poly(vinyl chloride) (PVC) and containing poly(hydroxypropyl acrylate) (PHPA), by using the controlled/“living” radical polymerization (CLRP) method. Various block copolymers containing a small proportion of PHPA were prepared, each having a different molecular weight. The technique used was the same as that employed in the production of commercial PVC made by free‐radical polymerization. The materials were characterized in terms of their molecular structure, morphology, particle size, and surface and thermal properties. The CLRP preparation of block copolymers that are based on PVC and have low contents of other monomer units opens the possibility of synthesizing new materials whose properties are close to those of PVC but have new properties that may considerably enhance their performance. The incorporation of small amounts of PHPA into PVC block copolymers provided greater surface hydrophilicity and improved thermal stability while maintaining relevant processing properties, such as particle size and average molecular weight, so that they close to those of conventional PVC homopolymers. J. VINYL ADDIT. TECHNOL., 19:157‐167, 2013. © 2013 Society of Plastics Engineers     

All-conjugated block copolymers

All-conjugated block copolymers of the rod-rod type came into the focus of interest because of their unique and attractive combination of nanostructure formation and electronic activity. Potential applications in a next generation of organic polymer materials for photovoltaic devices ("bulk heterojunction"-type solar cells) or (bio)sensors have been proposed. Combining the fascinating self-assembly properties of block copolymers with the active electronic and/or optical function of conjugated polymers in all-conjugated block copolymers is, therefore, a very challenging goal of synthetic polymer chemistry. First examples of such all-conjugated block copolymers from a couple of research groups all over the world demonstrate possible synthetic approaches and the rich application potential in electronic devices. A crucial point in such a development of novel polymer materials is a rational control over their nanostructure formation. All-conjugated di- or triblock copolymers may allow for an organization of the copolymer materials into large-area ordered arrays with a length scale of nanostructure formation of the order of the exciton diffusion length of organic semiconductors (typically ca. 10 nm). Especially for amphiphilic, all-conjugated copolymers the formation of well-defined supramolecular structures (vesicles) has been observed. However, intense further research is necessary toward tailor-made, all-conjugated block copolymers for specific applications. The search for optimized block copolymer materials should consider the electronic as well as the morphological (self-assembly) properties.     

Conducting copolymers of polypyrrole/polytetrahydrofuran

Summary Bifunctional living polytetrahydrofuran (PTHF) was terminated with potassium salt of pyrrole to yield polymers with electrochemically active end groups. These polymers were employed in the second stage to obtain conducting polypyrrole/polytetrahydrofuran block copolymers with short and long polytetrahydrofuran segments by potentiostatic anodic polymerization of pyrrole in different electrolytic media. Syntheses of block copolymers were achieved in media where tetrabutylammonium fluoroborate, sodium perchlorate and sodium p-toluenesulfonate were used as the supporting electrolytes. Characterizations were based on DSC, TGA, SEM, FTIR, and CV analyses. No significant effect of the chain length of polytetrahydrofuran segments on the properties of the copolymers was observed; however, thermal, electrochemical behaviors, and surface morphologies of the films were greatly affected by the supporting electrolytes. Received: 5 January 1998/Revised version: 25 March 1998/Accepted: 27 March 1998     

New phosphate glass/polymer hybrids—Current status and future prospects

The physical modification of polymer structure and properties via polymer blending and reinforcement is a common practice in the plastics industry and has a large economic advantage over synthesizing new polymeric materials to fulfill new material needs. In this context, a new class of inorganic glass/organic polymer hybrids with enhanced benefits has been recently developed by blending low-Tg phosphate glasses with polymeric materials in the liquid state, to afford new hybrid materials with significant improvements in properties that are impossible to achieve from classical polymer blends and composites. Because of their facile synthesis and desirable characteristics, these phosphate glass/polymer hybrid materials may be model systems for exploring feasibility of new routes for driving inorganic glasses and organic polymers to self-assemble into useful materials. Conceptually, it may even be possible to use block copolymers, with one block being miscible with Pglass, to perform self-directed assembly of nanostructured hybrids, where the Pglass is confined solely to one phase. This article reviews some new insights into the structural dynamics, melt rheology, molecular relaxation processes, and phase behavior of a few representative examples of these unique hybrid materials with prescribed rheological properties, macromolecular structure and function. The unanswered questions are discussed to guide future research directions, and facilitate progress in this emerging area.