ARCHITECTURE OF LADDER,TUBULAR AND SIEVE-PLATE POLYMERS PREPARED BY STEPWISE COUPLING POLYMERIZATION

"Stepwise-coupling polymerization" (SCP) is a very useful approach for preparing microstructure-controllableordered network polymers, including soluble one-dimensional ladderlike polymers (LP) and tubular polymers (TP), and two-dimensional sieve-plate polymers. The novel reactive LPs are important precursors of micro-structure controllable polymerssuch as "fishbone-" or "rowboat-"like mesomorphic polymers and their metal complexes as well as tubular polymers (TPs).They are full of great potential for use as advanced materials.     

Integrated Antimicrobial and Nonfouling Zwitterionic Polymers

Zwitterionic polymers are generally viewed as a new class of nonfouling materials. Unlike their poly(ethylene glycol) (PEG) counterparts, zwitterionic polymers have a broader chemical diversity and greater freedom for molecular design. In this Minireview, we highlight recent microbiological applications of zwitterionic polymers and their derivatives, with an emphasis on several unique molecular strategies to integrate antimicrobial and nonfouling properties. We will also discuss our insights into the bacterial nonfouling performance of zwitterionic polymers and one example of engineering zwitterionic polymer derivatives for antimicrobial wound‐dressing applications.     

Mesomorphic properties of liquid crystalline polysiloxanes and elastomers based on a tri-vinyl crosslinker

A series of crosslinked liquid crystalline polymers and the corresponding uncrosslinked liquid crystalline polymers were prepared by graft copolymerization; their liquid crystalline properties were characterized by DSC, POM and X-ray measurements. The results show that the crosslinking obtained in the isotropic state leads to a reduction of the clearing point (T_c) of the crosslinked polymers, as compared with the corresponding uncrosslinked polymers. The crosslinked polymers with low crosslinking density (P₁-P₇) exhibit nematic mesogenic phases, as do the uncrosslinked polymers. In contrast, a high crosslinking density leads to the crosslinked polymers P₈ and P₉ losing their thermotropic liquid crystalline phases; they instead exhibit stress-induced orientation.     

Living polymers. Their discovery,characterization, and properties

The story of the discovery of living polymers is presented. Living polymers are polymers that retain their ability to propagate and grow to a desired size while their degree of termination or chain transfer is still negligible. Theoretical and mechanistic considerations are discussed. The living polymerization technique provides access to uniform polymers (Poisson molecular weight distribution) of controllable size, block copolymers, functional polymers, and star and comb-shaped polymers. The quantitative aspects of electron transfer are fully discussed. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: ix–xv, 1998     

Stimuli-responsive star polymers

Stimuli-responsive star polymers gain more and more interest over the last decades due to their unique properties compared to their linear counterparts. The branched structure for instance has influence on the responsive behavior of these polymers. This review offers an overview of stimuli-responsive star polymers generated by different polymerization techniques, e.g. anionic and controlled radical polymerization (CRP). Beside conventional branched homopolymers different other types like block copolymers, miktoarm star copolymers, core crosslinked star polymers (CCS) and comb polymers are also presented. Furthermore their responsive behavior in solution or immobilized on a substrate, and their applications are outlined. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2980–2994     

New applications of poly(arylene ether)s in organic light-emitting diodes

Compared with conventional π-conjugated polymers,poly(arylene ether)s(PAEs) may take advantages of excellent thermal properties,well-defined effective conjugated length and no catalyst contamination.Recently,their applications have been extended from engineering plastics to optoelectronic materials.In this review,various kinds of functional PAEs used as fluorescent polymers,host polymers and phosphorescent polymers in organic light-emitting diodes(OLEDs) are outlined,and their molecular design,synthesis and device performance are overviewed.     

Conformation Control of Conjugated Polymers

In the past few decades, conjugated polymers have aroused extensive interest in organic electronic applications. The electrical performance of conjugated polymers has a close relationship with their backbone conformation. The conformation of the polymer backbone strongly affects the πelectron delocalization along polymer chains, the energy band gap, interchain interactions, and further affects charge transport properties. To realize a rigid coplanar backbone that usually possesses efficient intrachain charge transport properties and enhanced π–π stackings, such conformation control becomes a useful strategy to achieve high-performance (semi)conducting polymers. This minireview summarizes the most important polymer structures through conformation control at the molecular level, and then divides these rigid coplanar conjugated polymers into three categories: 1) noncovalent interactions locked conjugated polymers; 2) double-bond linked conjugated polymers; 3) ladder conjugated polymers. The effect of the conformation control on physical nature, optoelectronic properties, and their device performance is also discussed, as well as the challenges of chemical synthesis and structural characterization.     

Photosensitization of Two-dimensional Conjugated Polymers of Iron(Ⅱ)-and Cobalt(Ⅱ)-porphyrazine with Sulfur Bridges to CdS-PVA Film

Metal-porphyrazines (MPzs) and their polymers exhibit high thermal stability and unique photoelectric functions due to the macrocyclic planar structure and a delocalized π-electron system of the porphyrazine^[1-3]. We have been found that the metal-thioporphyrazines (MS_xPzs) and their conjugated polymers (PMS_xPzs) have usually peculiar a gas-sensitivity, photosensitivity and electrocatalytic activity^[5-8]. In the present abstract we report briefly photosensitization of the title polymers PMS₈Pz (see Scheme 1) to the CdS-PVA film.     

基于天然萜类的可持续性聚合物

随着可持续发展观念的逐步深入,可持续性聚合物已发展成为当今高分子领域的研究热点之一.萜类化合物作为自然界中一类来源广泛的天然资源,具有多种可修饰位点和丰富的功能性,由它出发制备可持续性聚合物,不仅可以简化聚合物的合成步骤,还可以赋予聚合物独特的立体构型、良好的生物活性和生物相容性等特点,进而拓展其在表面涂层、生物医药、组织工程等领域中的应用.本文综述了近年来国内外基于天然萜类可持续性聚合物的研究进展,从萜类化合物的结构特点出发,系统介绍了基于天然萜类可持续性聚合物的合成策略、特性及应用.     

Supramolecular structures based on dimeric combinations of cyclodextrin and adamantane via click chemistry

The cyclic starches α-, β-, and γ-cyclodextrins (CDs) readily form inclusion complexes (ICs) with a large variety of polymers. In polymer-CD-ICs, the CD hosts are threaded by the guest polymers, which must be highly extended, and stacks of polymer threaded host CDs pack closely together and crystallize. When guest polymers are coalesced from their CD-IC crystals, by washing with a solvent good, bad for CD, polymer, or treatment with an amylase enzyme, the guest polymers coalesce into bulk samples whose structures, morphologies, and even conformations are distinct from bulk samples made from their solutions and melts. We generally observe (i) crystallizable homopolymers coalesced from their CD-ICs to evidence increased levels of crystallinity, unusual polymorphs, and higher melting, crystallization, and decomposition temperatures, while coalesced amorphous homopolymers exhibit higher glass-transition temperatures, than samples consolidated from their disordered solutions and melts; (ii) molecularly mixed, intimate blends of two or more polymers that are normally believed to be immiscible can be achieved by coalescence from their common CD-IC crystals, (iii) the phase segregation of incompatible blocks can be controlled (suppressed or increased) when block copolymers are coalesced from their CD-IC crystals, and (iv) the thermal and temporal stabilities of the coalesced and well-mixed homopolymer blends and block copolymers appear to be substantial, thereby suggesting retention of as-coalesced structures and morphologies under normal thermal processing conditions. Furthermore, CDs may be covalently incorporated in polymers both during and after their syntheses, thereby providing a broad range of new functionalities for delivery of additives or to act as sensors or filters. Alternatively, additive-CD-ICs or additives rotaxanated with CDs may be effectively delivered to polymers. As an example, TiO₂—filled polypropylene fibers may be readily dyed in aqueous solution using water soluble CD-rotaxanated azo-dyes.     

Quinone-amine polymers. XII. Synthesis and characterization of novel polymers from 2-phenylbenzoquinone and aliphatic diamines

In order to study the effect of the presence of phenyl groups in poly (amino-quinone) (PAQ) polymers, several novel poly(amino-2-phenylbenzoquinone) (PhPAQ) polymers have been prepared from 2-phenylbenzoquinone and aliphatic diamines, such as 1,6-diaminohexane, 1,8-diaminooctane, 1,12-diaminodod+++++, and 1,4-diaminocyclohexane. Prior to the polymerization, 2-phenylbenzoquinone was generated in situ from 2-phenylhydroquinone in the presence of calcium hypochlorite as the oxidizing agent in dichloromethane. All of the polymers synthesized have been characterized with respect to their corresponding model compounds. It was also found that unlike their analogous PAQ polymers, PhPAQ polymers were highly soluble in many common organic solvents because of the presence of phenyl groups in their polymer backbone. © 1994 John Wiley & Sons, Inc.     

Synthesis,antibacterial evaluation and survey on the thermophysical characteristics of novel medically applicable polyamides containing pharmaceutically outstanding triazole moieties

There are many different strategies to decrease the incidence of infection of medical device and food related containers. One way to prevent infection is by modifying the polymers used in making the devices and containers. Incorporation of antimicrobial agents in the bulk material or in formulations of medical devices production has been considered a viable alternative for systemic application of antibiotics. In this article, preparation of a series of triazole containing polymers, poly(triazole-amide-imide)s (PTAI)s and poly(triazole-amide) (PTA)s, and their monomers are reported. These polymers were readily soluble in a variety of organic solvents, showed significant thermal properties and also viscosities in the range of 0.55–0.66 dL/g. They have been tested against a range of Gram-positive and Gram-negative pathogens. The results indicated that these novel polymers containing triazole moiety in their repeating units can effectively control Gram-positive and negative pathogens and their physic-chemical properties besides their antibacterial characteristics make them unique candidate for using in the manufacturing of the medical devices.     

Thermo-responsive polymers for thermal regulation in electrochemical energy devices

Thermo-responsive polymers have been widely explored because of their diverse structures and functions in response to temperature stimuli. Great attention has been attracted to exploring and designing such polymers composites, which offer tremendous opportunities to build up a systematic understanding of their structure–function relationships and pave the ways for their extensive applications in electronics, soft robotics, and electrochemical energy storage devices. Here, we review the most recent research of thermal regulation in electrochemical energy storage devices (e.g., batteries, supercapacitors) via thermo-responsive polymers. We summarize how battery components (i.e., electrolytes, separators, electrodes, or current collectors) can be coupled with thermo-responsive polymers based on different operation mechanisms, such as volume expansion, polymerization, phase reversion, and de-doping effects, to effectively prevent catastrophic thermal runaway. Different types of thermo-responsive polymers are evaluated to compare their key features and/or limitations. This review is concluded with perspectives of future design strategies towards more effective thermo-responsive polymers for battery thermal regulation.     

基于C–H活化的炔烃聚合反应合成多功能稠(杂)环聚合物

稠(杂)环聚合物是一类重要的功能聚合物,因其优异的光电特性而被广泛应用于光电领域.这类聚合物的传统制备方法往往需要用到修饰有复杂官能团的稠(杂)环单体,这些单体种类有限且合成难度大,导致稠(杂)环聚合物的发展受到限制. C–H活化过程的发现与提出为利用惰性的C–H键作为潜在官能团提供了可能,有效避免了对单体进行复杂修饰的要求,大大扩增了单体的种类和来源.基于C–H活化的炔烃环化聚合反应,能够在聚合物骨架中原位直接形成稠(杂)环结构,具有原料简单易得、聚合效率高、产物结构丰富等诸多优势,因此受到广泛关注.本文分类总结了基于C–H活化的炔烃环化聚合领域的最新进展,包括合成手段和所得聚合物的性质与功能介绍,并对该领域的未来发展方向进行了展望.     

Shear-induced Stabilization of the Nematic Phase in a Side Group-containing Poly (aryl ether ketone) Copol ymer

IntroductionPolarized optical microscopes (POM) are commonly used to identify liquid crystalline tex-tures. However, it is often found problematic to employ this technique in investigating themesophase transition of polymeric materials due to their higher viscosities. Rheological mea-surements at this juncture could provide us with valuable information about the mesophase- transition of liquid crystalline polymers[1]. Accordingly, there have been some rheological in-vestigations reported on …     

Simulating chromatographic separation of topologically different polymers

Chromatography which is sensitive to the sizes of macromolecules and to their adsorption serves as an appropriate method to separate complex polymers. Unfortunately, the molar mass also influences the chromatographic retention, thus making quite difficult the problem of separation of polydisperse polymers by their topology.By using a theory of chromatographic behavior of macromolecules, we simulate chromatograms of polydisperse polymers that differ solely in their topology, and discuss possibilities to separate complex polymers (such as eight-, tadpole-, theta-, manacle-shaped polymers, etc.) from their linear, branched, or macrocyclic precursors or topo-isomeric products.As follows from the simulations, two approaches towards the separation of polydisperse polymers by topology are especially promising. The first one is the chromatography at optimized (critical or near-critical) interaction conditions, where molar-mass effects are minimized; The second one consists in combing different chromatographic modes, which allows obtaining a separation by both molar mass and topology in a 2D chromatogram.Some of the simulated chromatographic separations are qualitatively very similar to the real ones, the others are the theoretical prediction.     

Recent advances in oxygen electrocatalysts based on tunable structural polymers

Due to their high energy density, great safety and eco-friendliness, zinc-air batteries (ZABs) attract much attention. During the process of charging and discharging, the two key processes viz. oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) limit their efficiency. In general, the noble metal-based electrocatalysts (ORR: platinum (Pt); OER: iridium (IV) oxide [IrO₂] and ruthenium oxide [RuO₂]) have long been used. Nonetheless, these noble metal electrocatalysts also have their limitations owing to high cost and poor stability. As alternatives, polymers are found to be most promising on account of their tunable structure, uniform network, high surface morphology and strong durability. Polymers are capable catalysts. In this review, recent advances as well as insight into the architecture of covalent organic polymers (COPs), metal coordination polymers (MCPs) and pyrolysis-free polymers (PFPs) are duly outlined.     

Thermal properties and crystalline structure of poly(10-undecene-1-ol)

Atactic and isotactic-rich poly(10-undecene-1-ol)s were synthesized by metallocene-catalyzed polymerization. The thermal properties and the crystalline structure of the poly(10-undecene-1-ol)s were characterized using Dynamic Scanning Calorimetry (DSC), Temperature-Modulated DSC (MDSC), Fourier Transform Infrared Spectroscopy (FTIR), and Wide-Angle X-ray Scattering (WAXS). It was found that the polymers crystallize primarily at their side chains, which is indicated by similar arrangement of both isotactic-rich and atactic polymers. The polymers form smectic layer structures independent on their tacticity, however, for the isotactic-rich polymers, higher crystallinities were observed than for the atactic polymers in terms of higher melting enthalpies.     

Metallocene-containing conjugated polymers

The paper gives a review of publications on polymers with conjugated matrices (PPy, PTh, PAni, hydrocarbon or mixed chains...) which incorporate metallocene complexes (Fe, Ru, Co; Ni, Ti, Zr, Ta) with two cyclopentadienyl ligands (Cp) and their derivatives, in particular with methylated cyclopentadienyl rings (Cp*), as well as hemi-metallocene complexes (Fe, Ru, Co, Mn), as pendant groups or inside the principal chain (part B). The information on related short-chain systems, monomers and oligomers, is also included. In part A, a brief overview of various conjugated polymer materials is presented, with their classification in accordance with the conductivity mechanism (ionic, electronic or mixed conductors) or with the structural type (linear-chain organic or mixed polymers, derivatization, metallopolymers, multi-dimensional structures, alternating and block copolymers with organic or mixed units, hybrid materials with a mixture of conjugated and inert polymers, polymers inside a solid matrix, conjugated polymers with incorporated nanoelements of transition metals, carbon, semiconductors etc.