Precise Stepwise Synthesis of Donor-Acceptor Conjugated Polymer Brushes Grafted from Surfaces

Donor-acceptor (D-A) conjugated polymers are promising materials in optoelectronic applications, especially those forming ordered thin films. The processability of such conjugated macromolecules is typically enhanced by introducing bulky side chains, but it may affect their ordering and/or photophysical properties of the films. We show here the synthesis of surface-grafted D-A polymer brushes using alternating attachment of tailored monomers serving as electron donors (D) and acceptors (A) via coupling reactions. In such a stepwise procedure, alternating copolymer brushes consisting of thiophene and benzothiadiazole-based moieties with precisely tailored thickness and no bulky substituents were formed. The utilization of Sonogashira coupling was shown to produce densely packed molecular wires of tailored thickness, while Stille coupling and Huisgen cycloaddition were less efficient, likely because of the higher flexibility of D-A bridging groups. The D-A brushes exhibit reduced bandgaps, semiconducting properties and can form aggregates, which can be adjusted by changing the grafting density of the chains.     

含噻吩的共轭微孔聚合物的合成与表征

以对溴碘苯为原料,通过Sonogashira偶联反应,Suzuki偶联反应,八羰基二钴催化的三聚反应,FeCl3氧化关环反应,成功合成了一种未见文献报道的含噻吩的六苯基苯共轭微孔聚合物,该共轭微孔聚合物经XRD测试为无序结构,TG研究结果表明热稳定性良好;其最大吸收峰位于380 nm处,发射出黄色荧光,该共轭微孔聚合物较单体波长发生红移,是聚合后链长增加共轭效应增强的结果。     

Synthesis of Poly(4,5-bis-hydroxy-1,3-cyclopentadienylene vinylene) from Poly(6,8-(1,5-dichloro-2,4-dioxa-3-keto)-bicyclo[3.3.0]octylene vinylene). Generation of a Conjugated Polymer by Hydrolysis of a Precursor Polymer

Hydrolysis of poly(6,8-(1,5-dichloro-2,4-dioxa-3-keto)bicyclo[3.3.0]octylene vinylene) results in the formation of poly(4,5-bis-hydroxy-1,3-cyclopentadienylene vinylene), a new conjugated polymer. This new system can be generated as a surface layer on its precursor polymer. The conversion process has been studied with the aid of infrared and optical spectroscopy, elemental analysis, microscopy and conductivity measurements.     

微孔塑料挤出成型中气泡成核的聚合物刷子模型

气泡成核是微孔塑料连续挤出成型中的关键步骤之一，临界气泡核直径是影响制品中泡孔直径的主要因素，成核密度则是影响制品泡孔密度的主要因素，但现有的成核理论大都是以经典成核理论为基础的，而经典成核理论虽然人出了临界气泡核及成核速率的计算公式，但并没有考虑到聚合物的物性参数，并且不能计算临界气泡核半径的具体数值，所以其应用有很大的局限性，从聚合物刷子模型出发建立气泡成核的刷子模型，从而得出临界气泡核半径的计算公式，并分析温度，压力，聚合物相对分子质量等对临界气泡核半径的影响。     

基于含2-硫代海因共轭聚合物的荧光探针

设计合成含2-硫代海因的小分子对照物1和聚苯撑乙炔poly(1)。通过一系列阴离子的正四丁基铵盐的DMSO溶液来评价聚合物的阴离子识别性能。加入F-后,poly(1)的DMSO溶液荧光淬灭;然而,加入Cl-,Br-,HSO-4,NO-3和CH3CO-2后,poly(1)溶液荧光不变,说明poly(1)对氟离子有荧光识别能力。Poly(1)对F-的Stern-Volmer淬灭常数为7.09×104M-1,相应地,对照物1对F-的Stern-Volmer淬灭常数为5.10×102M-1,说明了poly(1)具有增强淬灭效应。     

荧光共轭聚合物传感器的应用

介绍了共轭聚合物的荧光信号放大机理,综述了近年来作为传感器的荧光共轭聚合物的应用研究进展,以及共轭聚合物作为基材的传感器的种类、共轭聚合物在传感器方面面临的问题及研究方向。     

Thermal Decomposition of Polymer Mixtures Containing Poly(vinyl chloride)

Thermal decomposition of a series of 1 : 1 mixtures of typical polymer waste materials [polyethylene (PE), poly(propylene) (PP), polystyrene (PS), polyacrylonitrile (PAN), polyisoprene, poly(methyl methacrylate) (PMMA), polyamide‐6 (PA‐6), polyamide‐12 (PA‐12), polyamide‐6,6 (PA‐6,6), and poly(1,4‐phenylene terephthalamide) (Kevlar)] with poly(vinyl chloride) (PVC) was examined using thermal analysis and analytical pyrolysis techniques. It was found that the presence of polyamides and PAN promotes the dehydrochlorination of PVC, but PVC has no effect on the main decomposition temperature of polyamides. The hydrogen chloride evolution from PVC is not altered when other vinyl polymers or polyolefins are present. The thermal degradation of PAN is retarded significantly, whereas that of the other vinyl polymers is shifted to a slightly higher temperature in the presence of PVC. Among the pyrolysis products of PAN‐PVC mixture methyl chloride was found in comparable amount to the other gaseous products at 500°C pyrolysis temperature.     

Tubular Polymer Nanoobjects with a Crosslinked Shell and Inward‐Grafted Polymer Brushes

A simple route for preparing robust polymer nanotubes by SI‐ATRP within porous anodic aluminum oxide membranes and subsequent removal of the templates is presented. The nanotubes are composed of a crosslinked poly(styrene‐co‐divinylbenzene) shell and an inwardly grafted functional P4VP or PGMA brush‐like internal surface. The crosslinked skin endows the nanotubes with stability against organic solvents while the inwardly grafted polymer brushes supply the nanotubes with reactivity and functionalities. The inward PGMA hairs are post‐modified with sodium azides to introduce azido groups along tubular internal surfaces which are further reacted with propargyl alcohol. Structure and properties of the nanotubes are studied by SEM, TEM, LSCM, and FT‐IR spectroscopy.

     

荧光共轭聚合物在炸药探测中的应用

概述了炸药和炸药探测技术的种类以及荧光共轭聚合物的化学传感原理,综述了荧光共轭聚合物传感技术在炸药探测方面的应用研究进展以及取得的主要成就,并对其存在的主要问题做了简要的说明。提出高灵敏度、高信息负载度、低误判率的专用彩色聚合物炸药探测器件,在未来器件中有着更大的发展前景。     

水溶性共轭聚合物在荧光传感器上的应用进展

水溶性共轭聚合物具有良好的光电性质和良好的水溶性,在传感器方面表现出诱人的应用前景,因此近年来关于它们的研究备受瞩目。本文主要概述近年来以水溶性共轭聚合物为基础的荧光传感器在金属离子、小分子以及生物大分子检测方面的应用进展。     

Facile Incorporation of Silver Nanoparticles into Quaternized Poly(2‐(Dimethylamino)Ethyl Methacrylate) Brushes as Bifunctional Antibacterial Coatings

A simple strategy to fabricate bifunctional antibacterial coatings via in situ synthesis and incorporation of silver nanoparticles (AgNPs) into quaternized poly(2‐(dimethylamino)ethyl methacrylate) (qPDMAEMA) brushes without using any reducing agents is reported. PDMAEMA brushes are prepared on Si wafer substrates via surface‐initiated reverse atom transfer radical polymerization, which then are quaternized with ethyl bromide and hexyl bromide, respectively. The resulting qPDMAEMA‐AgNP nanocomposite coatings are characterized by using Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FE‐SEM), and Raman spectroscopy. FE‐SEM and Raman results indicate that the AgNPs with an average diameter of 35 nm are successfully loaded into the qPDMAEMA brushes. Furthermore, the antibacterial activities of the qPDMAEMA‐AgNP nanocomposite coatings against Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli are investigated by both disc diffusion and colony‐forming unit methods. The results show excellent antibacterial properties of the nanocomposite coatings. The influence of the length of the quaternization agents on their antibacterial properties is also investigated.

     

Synthesis and Surface Properties of Poly(methyl methacrylate)/Poly(ethylene glycol) Binary Brushes

A new kind of binary polymer brushes was synthesized from two immiscible polymers, PMMA and PEG, on GPS‐modified silicon wafers. Surface composition, layer thickness, coverage, chain density, wetting ability, morphology and protein adsorption of the binary brushes were investigated by XPS, ellipsometry, AFM and contact angle measurements. The results show that both PMMA and PEG were successfully grafted onto the surface. The surface coverage and the chain density of PMMA and PEG brushes can be controlled by modulating the reaction temperature and time. This kind of binary polymer brushes exhibits a distinct microphase‐separated structure and excellent protein‐preventing property.

     

Excellent Polyimide Dielectrics Containing Conjugated ACAT for High-Temperature Polymer Film Capacitor

In order to meet the requirements of polymer dielectric materials for high thermal stability and excellent dielectric properties in the application of high-temperature film capacitors, a series of polyimide (PI) films are fabricated by introducing a self-synthesized aniline trimer (ACAT) with a conjugated structure in this work. Since the conjugated ACAT in the main chains of PI improves the electron polarization and carrier mobility of the PI molecular chains, the dielectric constant of the ACAT-PI films is greatly enhanced (4.4–7.4). Meanwhile, the dissipation factor does not increase apparently (0.002–0.013). The dielectric properties are stable even when the temperature is up to 200 °C, the thermal degradation temperature is as high as 450 °C, and the mechanical properties are also excellent (70–105 MPa). Among all the films, the PI film with 5 mol% ACAT exhibits the maximal energy density of 3.6 J cm⁻³ under the field of 426 kV mm⁻¹, the high tensile strength (90 MPa) and the excellent thermal stability (T_d5 = 515 °C). The work paves the way to prepare high-temperature polymer dielectric film materials with high energy storage density.     

Synthesis,spectroscopy, and electrochemical investigation of new conjugated polymers containing thiophene and 1,3,4-thiadiazole in the main chain

Novel photoluminescent donor–acceptor poly(p-phenylenevinylene)-type conjugated polymers containing thiophene and 1,3,4-thiadiazole units in the main chain were synthesized from 2,5-bis(5-bromomethyl-2-thienyl)-1,3,4-thiadiazole and 1,3/1,4-benzenedialdehyde by Wittig–Horner reaction. The synthesized polymers were characterized by the use of thermal analysis and spectroscopic (infrared, UV-visible absorption, and photoluminescence) measurement. The resultant material exhibited bluish green, green, and orange fluorescence in their solution and thin film and solid forms, respectively. The redox property of the polymers has also been studied by cyclic voltammetry. The optical and electrochemical studies reveal that these novel polymers are new promising materials for the development of efficient polymer light-emitting diodes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

侧链含有环糊精的聚合物的研究进展

聚合物侧链可通过化学键及分子间力与环糊精相互作用。当聚合物侧链通过化学键与环糊精作用时,环糊精空腔一般为空,可与小分子包合,对不同立体结构的分子具有选择性,在分析化学方面具有潜在的应用。当聚合物侧链与环糊精包合时,环糊精空腔与一定结构的侧链包合,形成侧链型多聚(准)轮烷。侧链型环糊精基多聚(准)轮烷的结构、性能独特,在许多领域具有潜在的应用。本文介绍了国内外文献中关于侧链含有环糊精的聚合物的研究进展,包括合成方法以及在各领域的应用等。     

聚合物电致发光材料与器件(待续)--聚合物发光材料

1990年Burroughes采用聚对苯乙炔(PPV)作为有源层制作聚合物电致发光器件,开创了共轭聚合物科学的新领域,由于聚合物电致发光器件具有制备简单、发光效率和发光亮度高、发光波长易于调节等显著特点,引起了各国的高度重视,大量的共轭聚合物材料成功地应用于电致发光器件,使得电致发光聚合物材料和器件的研究成为近年来最活跃的领域之一.     

Luminescence properties of poly‐ (phenylene vinylene) derivatives

BACKGROUND: Conjugated polymers, especially those of the poly(phenylene vinylene) (PPV) family, are promising candidates as emission material in light‐emitting devices. The aim of this work was to investigate the dependence of the luminescence properties of PPV‐based derivatives on their polymer structure, especially side groups. RESULTS: Three PPV derivatives, BEHPPV, MEHPPV and MEHSPPV, were synthesised and characterised by photoluminescence (PL) and cathodoluminescence (CL) spectroscopies in the temperature range 10–300 K. PL and CL spectra of the polymers exhibit similar luminescence peaks, which undergo a blue shift with increasing temperature. The shift in wavelength is accompanied by variations in the relative intensities of emission peaks. Both BEHPPV and MEHPPV display emission characteristics of the PPV backbone, but the peak of MEHPPV shifts to a longer wavelength in comparison with the corresponding peak of BEHPPV at the same temperature. The luminescence spectra of MEHSPPV, which has a sulfanyl incorporated in the side chain, are considerably different from those of the two other derivatives. CONCLUSIONS: The results demonstrate that the luminescence properties depend strongly on the chain conformations of the conjugated backbone, which are affected by polymer side chains. Copyright © 2007 Society of Chemical Industry     

Blends Containing Amphiphilic Polymers VI. Compatibilization of N-alkylitaconamic acid-co-Styrene Copolymers with Poly(hydroxypropyl methacrylate) and Poly(4-vinylphenol)

Blends containing copolymers of N-alkylitaconamic acid (NAIA) with styrene (NAIA-co-S) of two copolymer compositions, that is, 80% and 50% styrene, with poly(hydoxypropyl methacrylate (PHPM) and poly(vinyl phenol) (PVPh) were studied by differential scanning calorimetry (DSC) and Fourier Transform Infrared spectroscopy (FT-IR). The phase diagrams of Tg against blend composition show one single Tg value, which are intermediate to those of the pure components. This is interpreted as miscibility over the whole range of compositions in both systems. The Calorimetric Analysis using Gordon Taylor, Couchman, and Kwei treatments allows one to conclude that interactions between the components is favorable to the miscibility. FT-IR spectra show important displacements in the wavenumber corresponding to the carbonyl groups of the itaconamic acid moiety. This behavior is atributed to strong interaction by hydrogen bonds formation, taking into account that PHPM and PVPh are interacting polymers. FTIR analysis of the blends suggests that the driving force for miscibility is hydrogen bonds formation. The variation of the absorptions of the carbonyl groups of PNAIA and the hydroxyl groups of P4VPh allows to attribute the miscibility to weak acid-base like interactions.     

聚乙二醇中共轭烯炔化合物的合成

发展了一种在聚乙二醇介质中末端炔烃与缺电子炔烃选择性生成共轭烯炔化合物的方法。在三苯基膦氯化钯(2mol%)、溴化亚铜(4mol%)、PEG-400(1.0g)和氮气的作用下,1mmol末端炔烃与0.5mmol缺电子炔烃可以顺利地发生交叉偶联反应选择性生成相应的共轭烯炔化合物,该反应产率较高,对环境友好,且催化体系可以适当地重复使用。     

聚合物发光电化学池研究进展

共轭聚合物是一类结合了光学、半导体电子性能和聚合物加工性能的新型材料,1995年聚合物发光电化学池出现以来就引起了广泛关注,文章在对文献结果分析的基础上总结了影响聚合物发光电化学池性能的若干因素和最新的研究进展。