导电性高聚物化学的进展

对近年来国内外导电高聚物在合成,结构与性能的关系,导电机理及其应用等方面进行了介绍和评述。     

Oxidation potential of thiophene oligomers: Theoretical and experimental approach

Intrinsic properties of conducting polymers, such as oxidation potential and band gap, are very important for designing new materials with improved properties. Computational chemistry offers suitable tools capable of predicting these quantities. This work presents electrochemical information about accurate oxidation potentials of oligothiophenes and polymer band gap. These are compared to theoretical predictions based on electronic structure calculations at Density Functional Theory levels, coupled with self‐consistent reaction field. All computational protocols gave a qualitative prediction of the experimental trend. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

Band gap tuning of narrow‐polydispersity two‐dimensional conductive polymers with electroactive side‐chains

A series of two‐dimensional donor–acceptor–donor (D1–A(D2)) type of conducting polymers (CPs) all with electroactive bulky side chain structure has been designed, synthesized, and investigated by introducing the donor–acceptor (D1–A) thiophene–quinoxaline moiety in the main chain alongside and additional donor and hole transporting units in the side chain. All the UV‐vis spectra of the 2D polymers, PTPQT, PFPQT, and PCPQT, each with triphenylamine, fluorene, and carbazole units as the D2 side chain, possess strong intramolecular charge transfer absorption, thus resulting in better light harvesting. Their optical and electronic properties were thoroughly explored experimentally and computationally. The effect of molecular weight of the narrow polydispersity polymers on their optoelectronic property was studied in detail. In summary, the 2‐D CPs show potential for use as an active material in optoelectronic devices. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1217–1227     

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.     

Photovoltaic response to structural modifications on a series of conjugated polymers based on 2‐aryl‐2H‐benzotriazoles

The synthesis, characterization, and photovoltaic properties of a series of four conjugated polymers containing 2‐aryl‐2H‐benzotriazoles and “bis(thiopheno)dialkylfluorenes” is described. The polymers were obtained via Suzuki‐polycondensation and comprise alternating electron rich and electron poor building blocks. The impact of systematic structural changes on the electronic and morphological properties and device efficiencies were studied. Application of these polymers as light‐harvesting and electron‐donating materials in organic solar cells using PCBM derivatives as electron accepting materials resulted in power conversion efficiencies up to 1.8%. Both the properties of the pristine polymers and the device performance show that the impact of the substitution farther‐off the backbone is negligible while substitution directly on the backbone has a major impact. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Platinum‐segmented polydiacetylenes

We report the synthesis and characterization of a novel series of platinum‐segmented polydiacetylenes (Pt‐PDAs). These polymers can be considered PDAs having every other double bond replaced with a Pt center and fully conjugated side groups attached to the remaining double bonds. Physical, optical and electronic properties of these polymers can be systematically tuned by changing the side groups from alkyl to phenyl and to thienyl moieties. Application of these polymers in solution‐processed organic photovoltaic devices is attempted and evaluated. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2662‐2668     

Preparation and characterization of polyfuran/poly(2‐fluoroaniline) conducting composites

This article deals with the chemical synthesis and characterization of poly(2‐fluoroaniline) (P2FAn) and polyfuran (PFu) homopolymers and PFu/P2FAn and P2FAn/PFu composites. P2FAn and PFu homopolymers were synthesized using ammonium persulfate and antimony (III) chloride as catalyst, respectively. These homopolymers and composites were studied in the doped state using Fourier transform infrared spectroscopy and ultraviolet–visible absorption spectroscopy, thermogravimetric analysis, scanning electron microscopy, four‐probe conductivity technique, and Gouy Scale measurements. PFu/P2FAn and P2FAn/PFu composites were found to possess different thermal, conductivity, electronic, and morphological properties from each other when synthesis order of guest and host polymers was varied. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3359–3367, 2004     

Preparation of conducting poly(vinyl chloride)/polyindole composites and freestanding films via chemical polymerization

This study covers the synthesis of conducting polyindole (PIN) homopolymer, poly(vinyl chloride)/polyindole (PVC/PIN) composites, and preparation of their freestanding films. PIN and composites were synthesized chemically by radicalic mechanism using FeCl₃ as an initiator. Films of PVC and PVC/PIN composites were prepared by casting on glass Petri dishes. Mechanical properties of films were examined by stress–strain experiments. From FTIR spectra of polymers, it was revealed that polymerization reaction occurred by 2–3 mechanism. The conductivities of polymers at different temperatures were also measured by four‐probe technique and found in the range 10^?4 to 10^?5 S cm^?1. Magnetic properties of the polymers were analyzed by Gouy scale measurements and were found that their conducting mechanisms are of polaron and bipolaron natures. Thermal properties of polymers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and found that they had shown adequate thermal stability. X‐ray diffraction (XRD) spectra showed the amorphous nature of the polymers. Scanning electron microscopy (SEM) was used for microstructural analysis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1290–1298, 2010     

Living polymerization of substituted acetylenes

For many years, considerable research efforts have been dedicated to π‐conjugated polymers because of their extraordinary electronic, optical, and structural properties. The employed transition‐metal‐based initiating systems comprise not only simple transition‐metal salts but also rather sophisticated mixtures of two, three, or four compounds and even highly defined single‐component systems such as transition‐metal alkylidene complexes. Extensive fine‐tuning of the electronic and steric properties of initiator–monomer systems eventually allowed the tailor‐made synthesis of conjugated materials via living polymerization techniques. This article focuses on recent developments in the field of the living polymerization of substituted acetylene derivatives. Ill‐defined group 5 and 6 transition metal halide‐based initiators, well‐defined transition‐metal alkylidene complexes, and rhodium(I)‐based systems that induce the living polymerization of numerous substituted acetylenes are reviewed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5723–5747, 2005     

Synthesis and properties of new ultraviolet–blue‐emissive fluorene‐based aromatic polyoxadiazoles with confinement moieties

Three families of fluorene–oxadiazole‐based polymers with confinement moieties have successfully been prepared by the two‐step method for polyoxadiazole synthesis. These polymers show good solubility in common organic solvents, high thermal stability, and strong violet and blue photoluminescence in solution and as films, respectively. Their low‐lying highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels originate from the electron deficiency of an oxadiazole moiety, and this suggests that they may be useful for blue‐emitting and electron‐transport/hole‐blocking layers in electroluminescent devices. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 674–683, 2003     

Optimization of direct arylation polymerization (DArP) through the identification and control of defects in polymer structure

As a newly emerged protocol for the synthesis of conjugated polymers, direct arylation polymerization (DArP) is an environmentally friendly and cost-effective alternative to traditional methods of polymerization. DArP efficiently yields conjugated polymers with high yield and high molecular weight. However, DArP is also known to produce defects in polymer chemical structure. Together with molecular weight and polydispersity, these defects are considered to be important parameters of polymer structure and they have a strong impact on optical, electronic and thermal properties of conjugated polymers. The four major classes of conjugated polymer defects inherent for DArP have been identified: homocoupling regiodefects, branching defects, end group defects, and residual metal defects. To have a precise control over the polymer properties, it is important to understand what causes the defects to form during the polymerization process and be able to control their content. Here within the scope of current literature, we discuss in detail the definition and origin of all these defects, their influence on polymer properties and effective means to control the defects through fine tuning of the DArP reaction parameters. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 135–147     

Arborescent polymers and other dendrigraft polymers: A journey into structural diversity

Arborescent polymers are characterized by a dendritic, multilevel branched architecture derived from successive grafting reactions. In spite of their much larger size, these materials display properties analogous to dendrimers and hyperbranched polymers, the two other dendritic polymer families. The distinguishing features of arborescent polymers are their assembly from polymeric building blocks of uniform size and their very high molecular weights attained in few synthetic steps. This article offers an overview of the historical aspects of the development of dendrigraft polymers, starting from our initial efforts on the synthesis of arborescent polystyrenes. Major subsequent developments in the synthetic techniques from our and other research groups allowing the synthesis of dendrigraft copolymers, tailoring of the structural characteristics of the molecules, and further simplifications to their synthesis are also reviewed, with emphasis over the broad range of architectures attainable in these systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3803–3810, 2007     

Nanoscale structure–property relationships in conjugated polymers: Implications for present and future device applications

The most prevalent molecular level structures and structure–property relationships for three basic classes of conjugated polymers are summarized. This discussion encompasses linear unsubstituted conducting polymers and those containing linear side‐chain and branched side‐chain substituents. The impact of these structural attributes on charge transport and photophysics is emphasized. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2630–2648, 2003     

Conductivity,morphology, interfacial chemistry,and stability of poly(3,4‐ethylene dioxythiophene)–poly(styrene sulfonate): A photoelectron spectroscopy study

X‐ray photoelectron spectroscopy (XPS) has been used to characterize poly(3,4‐ethylene dioxythiophene)–poly(styrene sulfonate) (PEDT/PSS), one of the most common electrically conducting organic polymers. A correlation has been established between the composition, morphology, and polymerization mechanism, on the one hand, and the electric conductivity of PEDT/PSS, on the other hand. XPS has been used to identify interfacial reactions occurring at the polymer‐on‐ITO and polymer‐on‐glass interfaces, as well as chemical changes within the polymer blend induced by electrical stress and exposure to ultraviolet light. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2561–2583, 2003     

Chemical Biological Sensors Based on Advances in Conducting Electroactive Polymers

Advances in conducting electroactive polymers (CEPs) have driven the design of novel chemical and biochemical sensors. The redox properties of CEPs have been intensely studied for more than two decades with emphasis on their synthesis and characterization. Little attention has been paid to the importance of mechanism in sensor designs. However, in order to design robust and stable sensors, it is important to understand how the polymer structure, morphology, adhesion properties and microenvironment affect sensor performance. This work describes how chemical and biological sensors have been designed, fabricated, characterized and tested based on the fundamental understanding in CEPs. The use of photopolymerized conducting polymers in sensor designs is described. Four focus areas are presented in which the electronic properties of CEPs have enabled the design of novel sensors for organics, nucleic acids, biological molecules, vapors and metal ions.     

Pi‐conjugated chain extenders for the synthesis of optoelectronic segmented polyurethanes

The optical properties of mechanochromic materials change under mechanical stress. Segmented polyurethanes are elastomers composed of amorphous, saturated chain soft segments, and rigid pi‐conjugated hard domains. Within aggregates of hard domains pi–pi interactions may form and result in perturbation of the optoelectronic properties of the system. Disruption and restoration of these electronic interactions within the material may lead to observable mechanochromic response. A series of oligothiophene diols and diamines, as well as a naphthalene diimide diol, have been synthesized for incorporation into the hard domains of segmented polyurethanes and polyureas using long poly(tetramethylene oxide) chains as soft segments. The resulting polymers were evaluated to determine their extent of polymerization and their thermal stability. The optical properties of the materials were studied in solution and as thin films. Where possible the electrochemical properties of the polymers were also explored. The length of the soft segment chains in the segmented polyurethanes hindered electronic coupling of hard domains. Future work involving smaller, more solubilizing soft segments may allow for easier material characterization and mechanochromic response. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Conducting polymers: Efficient thermoelectric materials

This review highlights the recent progress made in the area of thermoelectric (TE) applications of conducting polymers and related composites. Several examples of such materials and their TE properties are discussed. TE properties of new poly(2,7‐carbazole) derivatives are highlighted. References are also made to carbon nanotube/polymer composites and their improved electrical and TE performance. Studies on polymer/inorganic materials composites have also taken a step forward and have shown very promising TE properties. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

Graft polymer synthesis by RAFT transfer-to

The synthesis of graft polymers via controlled polymerization techniques has enabled the facile modification of the surface properties of a variety of substrates. Three grafting methods are typically highlighted in the literature: grafting-to, grafting-from, and grafting-through. However, a fourth method exists when grafting is conducted using reversible addition-fragmentation chain transfer (RAFT) polymerization, which we refer to as transfer-to. Transfer-to differs from the other grafting strategies in the types of structural defects and impurities that arise during polymerization. This review addresses important considerations when conducting RAFT transfer-to, including RAFT chain transfer agent selection, monomer structure, and reaction conditions. In addition, we highlight key mechanistic differences between grafting-from and transfer-to and their effects on the structure and sample composition of the resulting graft polymers. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2865–2876     

Substituent effect on azobenzene‐based liquid‐crystalline organophosphorus polymers

An Erratum has been published for this article in Journal of Polymer Science Part A: Polymer Chemistry (2003) 41(23) 3862 A new series of combined‐type, azobenzene‐based organophosphorus liquid‐crystalline polymers were synthesized, and their photoisomerization properties were studied. The prepared polymers contained azobenzene units as both the main‐chain and side‐chain mesogens. Various groups were substituted in the terminal of the side‐chain azobenzene mesogen, and the effects of the substituents were investigated. All the polymers were prepared at the ambient temperature by solution polycondensation with various 4‐substituted phenylazo‐4′‐phenyloxyhexylphosphorodichloridates and 4,4′‐bis(6‐hydroxyhexyloxy) azobenzene. The polymers were characterized with gel permeation chromatography, Fourier transform infrared, and ¹H, ¹³C, and ³¹P NMR spectroscopy. Thermogravimetric analysis revealed that all the polymers had high char yields. The liquid‐crystalline behavior of the polymers was examined with hot‐stage optical polarizing microscopy, and all the polymers showed liquid‐crystalline properties. The formation of a mesophase was confirmed by differential scanning calorimetry (DSC). The DSC data suggested that mesophase stability was better for electron‐withdrawing substituents than for halogens and unsubstituted ones. Ultraviolet irradiation studies indicated that the time taken for the completion of photoisomerization depended on the dipolar moment, size, and donor–acceptor characteristics of the terminal substituents. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3188–3196, 2003     

Polypropylene fractions produced by binary metallocene catalysts

Because of the great economic interest in propylene‐based polymers and the possibility of designing materials with desired properties with metallocene catalyst mixtures, we investigated the characteristics of polypropylenes produced by mixtures of SiMe₂Ind₂ZrCl₂: dimethylsilane‐bis(indenyl) zirconocene ( 1 ) and Et(Flu)(Cp)ZrCl₂: ethylidene (fluorenyl cyclopentadienyl) zirconocene ( 2 ) in different proportions. The polymers were fractionated with solvents, and the fractions were characterized. We observed that the polymers produced by the different mixed systems showed lower weight‐average molecular weights and only slightly broader molecular weight distributions than polypropylenes synthesized by the individual catalysts. We concluded that catalyst 1 acted independently of catalyst 2 , producing polymers with the same isotacticity. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1478–1485, 2003