GO-PTAm:一种高性能锂离子电池正极材料

通过原子转移自由基聚合法（ATRP法）制备了聚（4-丙烯酰胺基-2,2,6,6-四甲基哌啶-1-氧基）-氧化石墨烯（PTAm-GO）复合材料。采用红外、拉曼、X射线衍射、热重、电子顺磁共振等手段对复合材料进行了表征，将活性材料作为正极组装成扣式电池，测量扣式电池的循环伏安图、电化学阻抗谱和充放电循环容量。结果表明，PTAm-GO电极可以发生可逆的氧化还原反应，且具有比PTAm更低的电化学阻抗和高出约两倍的充放电容量，经过300次充放电循环后，电极比容量保持在138 mAh/g，容量保持率为96.5 %。这对有机电池的发展，特别是对氮氧化物自由基聚合物电极材料的研究具有重要的参考价值。     

Atom Transfer Radical Polymerization: From Mechanisms to Applications

Atom transfer radical polymerization (ATRP) is currently one of the most often used synthetic polymerization methods to prepare well-defined polymers with complex architecture. This review covers some fundamentals of copper-based ATRP, presents basic structure–reactivity correlation for initiators and catalyst complexes and discusses the radical nature of reactive intermediates. New ATRP initiating processes with ppm amounts of copper catalysts and various reducing agents are described together with recent electrochemically controlled ATRP and polymerization in aqueous homogeneous and dispersed media. Examples of polymers with precisely controlled architecture are presented together with the effect of variable amounts of catalysts on molecular weight distribution and morphology of nanostructured block copolymers. Some current and forthcoming applications of polymers made by ATRP are presented.     

Transition-Metal Catalysts for Controlled Radical Polymerization: A First Update

This article, a follow-up on a recent review co-authored by one of us (Prog. Polym. Sci. 2010 , 35, 959–1021) discusses the most recent discoveries in the field of metal-catalyzed, reversible-deactivation radical polymerization. Remarkable examples include the use of non-toxic polyethylene glycols simultaneously as solvents and ligands for the iron-catalyzed ATRP, nickel complexes that promote polymerization via a dual radical/migratory-insertion pathway, and metalloenzymes as mediators of ARGET ATRP-type reactions. A thorough and critical overview of the mechanistic details as well as the experimental conditions used to carry out the polymerizations are given together with an overview of the future challenges.     

Sulfur‐replaced Fenton systems: can sulfate radical substitute hydroxyl radical for advanced oxidation technologies?

Sulfate radicals (SO₄^??) and hydroxy radicals (HO^?) are the major radicals used in advanced oxidation technologies (AOTs) for the removal of contaminants. Although SO₄^?? reacts with organic or inorganic compounds with rate constants comparatively lower than that of HO^?, AOTs based on SO₄^?? (abbreviated as SR‐AOTs) have gained lots of attention due to the selective oxidation and non‐pH‐dependence. A series of systems using persulfate (PS) or peroxymonosulfate (PMS) instead of H₂O₂ is designated as a sulfate radical‐Fenton system or sulfur‐replaced Fenton system (SR‐Fenton). Comparisons and analogies between Fenton (Fenton‐like) systems and SR‐Fenton systems are made and some new SR‐AOTs systems without PS or PMS are introduced. The possibility for the substitution of HO^? by SO₄^?? for AOTs is discussed. Most likely in the future, efforts will be concentrated on product‐oriented AOTs with the purpose of recovery of chemical products rather than mineralization of organic contaminants, producing greenhouse gas CO₂. Moreover, such SR‐Fenton system may be more atomically economical. © 2014 Society of Chemical Industry     

可控自由基聚合技术在涂料树脂合成中的应用

可控自由基聚合技术（CRP）作为一种能够实现对产品分子结构控制的新型聚合方法,对于合成高性能树脂和高分子助剂而言,具有特别重要的意义。本文对主要的可控聚合方法反应机理进行简述,并介绍可控聚合法在高固体分涂料树脂、功能型涂料树脂和水性树脂合成中的应用。     

Specific cationic photoinitiators for near UV and visible LEDs: Iodonium versus ferrocenium structures

Two iodonium salts based on a coumarin chromophore are investigated for polymerization upon light emitting diode irradiations (LEDs). They work as one‐component photoinitiators. They initiate the cationic polymerization of epoxides (under air) and vinylethers (laminate) upon exposure to violet LEDs (385 and 405 nm). Excellent polymerization profiles are recorded. Their efficiency is quite similar to that of a ferrocenium salt. Interpenetrating polymer networks can also be obtained through a concomitant cationic/radical photopolymerization of an epoxy/acrylate blend monomer. The light absorption properties of these new salts as well as the involved photochemical mechanisms are investigated for the first time through electron spin resonance, laser flash photolysis, steady state photolysis experiments. Molecular orbital calculations are also used to shed some light on the initiation mechanisms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42759.     

三白草提取物对自由基的清除作用研究

考察了三白草乙醇提取物经不同溶剂萃取所得的各部分对1,1-二苯基-2-三硝基苯肼(DPPH)自由基、羟基自由基和超氧自由基的清除能力。以2,6-二叔丁基-4-甲基苯酚(BHT)为参考。结果表明,三白草乙醇提取物经不同溶剂萃取所得的各部分对DPPH自由基、羟基自由基和超氧自由基都具有清除能力,且随着提取物浓度的增加,清除能力逐渐增高;其中乙酸乙酯部分对DPPH自由基、羟基自由基和超氧自由基的清除作用最强。     

Pro‐oxidant and Antioxidant Effects in Photodynamic Therapy: Cells Recognise that Not All Exogenous ROS Are Alike

Photodynamic therapy (PDT) uses light, photosensitizer molecules and oxygen to generate reactive oxygen species (ROS) that kill cancer cells. Redaporfin, a new photosensitizer in clinical trials, generates both singlet oxygen and superoxide ions. We report the potentiation of redaporfin–PDT in combination with ascorbate and with the inhibition of antioxidant enzymes in A549 (human lung adenocarcinoma) and CT26 (mouse colon adenocarcinoma) cells. The addition of ascorbate and the inhibition of superoxide dismutase (SOD) strongly increased the phototoxicity of redaporfin towards A549 cells but not towards CT26 cells. The inhibition of catalase and the depletion of the glutathione pool also potentiate redaporfin–PDT towards A549 cells. The lower SOD activity of A549 cells might explain this difference. SOD activity levels may be explored to increase the selectivity and efficacy of PDT with photosensitizers that generate radical species.     

Amphiphilic acrylate copolymer fatliquor for ecological leather: Influence of molecular weight on performances

With increasing demand for ecological leather, ecological fatliquors with good comprehensive properties are getting more and more attention. The amphiphilic acrylate copolymer containing both hydrophilic (carboxyl) and hydrophobic (long alkyl) groups is one of the main alternatives to conventional fatliquors. In this paper, a series of poly(acrylic acid‐co‐stearyl acrylate) with different relative molecular weights were prepared, and the influence of the molecular weight on their application performances were evaluated. The results show that lower relative molecular weight of copolymers is conducive to the penetration and absorption, and it improves the softness and fiber separation of leather. When the number average molecular weight (M_n) of copolymer is higher than 25,000, its penetration and absorption become worse and the resulting leather feels hard. In addition, the amphiphilic acrylate copolymers can impart excellent oxidation resistance and transference resistance to leather, which is a considerable improvement over the conventionally retanned and fatliquored leather. The copolymer has great penetration and absorption ability when M_n is within the range of 9,000–15,000, and it gives leather excellent integrated properties, such as filling, softness, mechanical strength, extraction resistance, and oxidation resistance, which can meet requirements of ecological leather. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43440.     

Efficient Benzodioxole‐based unimolecular photoinitiators: From synthesis to photopolymerization under UV‐A and visible LED light irradiation

The narrow emission spectra of light emitting diodides (LED) as irradiation source has brought great challenge for the development of efficient photoinitiators sensitive to LED light. This paper described a series of novel unimolecular type II photoinitiators, containing thioxanthones as chromophores and benzodioxoles as coinitiators. The structures of the photoinitiators were characterized by ¹H NMR, ¹³C NMR and high‐resolution mass spectrometer. Study on the photophysical properties of the photoinitiators indicated that electron donors/acceptors as spacers between thioxanthone and benzodioxole affected both the UV–Vis absorption and the fluorescence emission. The long wavelength absorptions from 385 nm to 402 nm as well as low fluorescence quantum yields make the investigated benzodioxole derivatives quite attractive as efficient photoinitiators under UV‐A and visible LED light irradiation. With a proper molecular design, the unimolecular photoinitiator exhibited higher initiation efficiency than the thioxanthone derivatives from the literature. Possible initiation mechanism was also proposed based on the photolysis study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43239.     

国内外子午线轮胎发展概况

介绍了国外子午线轮胎的开发现状和发展趋势；分析我国子午线轮胎开发现状并对今后的发展提出了建议。     

High‐performance carboxylate superplasticizers for concretes: Interplay between the polymerization temperature and properties

Polycarboxylate superplasticizers based on acrylic acid (AA) and maleic anhydride (MAn) were synthesized via free‐radical copolymerization with an ethylene glycol monomer and characterized. The copolymerization temperature (ranging from 50 to 90 °C) appeared to be the key operating factor governing the chemical structure of the superplasticizers. The chemical structures of the products were analyzed by gel permeation chromatography, whereas an optimized sample was further analyzed by Fourier transform infrared spectroscopy and ¹H‐NMR. Superplasticizers of the AA and MAn classes were then incorporated into concrete, and their performances were measured by slump and slump loss tests, where a large dependency of the microstructure on the synthesis temperature was recognized. The optimum temperatures were found to be 50 and 80 °C for the AA and MAn modifiers, respectively. At their own optimum temperatures, the AA and MAn superplasticizer revealed slump losses from 23 to 4 cm and 15 to 5 cm, respectively, after 45 min. The chemical structures of the plasticizers were patterned illustratively to speculate the performance of each superplasticizer according to changes that took place in the backbone length and side‐chain density. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44908.     

Synthesis and properties of thermoplastic expandable microspheres: The relation between crosslinking density and expandable property

A set of thermoplastic expandable microspheres was investigated with respect to their crosslinking density and expandable property. The crosslinking efficiencies of dipentaerythritol hexaacrylate in a set of thermoplastic expandable microspheres were measured. As expandable properties, expansion curves were measured by using a thermomechanical analyzer, and they also were shown by measuring the change of thickness of the coated compound consisting of ethylene–vinyl acetate copolymer resin emulsion and CaCO₃ with thermoplastic microspheres on paper. In view of the expansion ratio and heat resistance, as crosslinking density, a swelling ratio of about 20–25 is needed to achieve optimum expansion without collapse and rupture of microspheres. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 505–512, 2004     

Free radical behavior in thermal cracking reaction using petroleum heavy oil and model compounds

Thermal cracking mechanism of heavy oil, especially an effect of hydrogen partial pressure was investigated in the thermal cracking reaction using model compounds and Kuwait Vacuum Residue (KW-VR). Free radical recombination was not affected by the change of hydrogen partial pressure.     

Acrylic-ester-polyol based novel two-component polyurethane clear coat: Evaluation of performance characteristics

In the current study, a combination of acrylic polyol (AP) and ester polyol (EP) were synthesized and reacted at variable ratios with hexamethylene diisocyanates and isophorone diisocyanates to prepare a transparent two-component polyurethane (PU) coating formulation. The formations of the polyol system, isocyanate system, and the PU systems were confirmed by ¹H nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Transparency of the coatings was examined using haze, and gloss measurement, which showed acrylic-ester-polyurethane (aePU-5 and aePU-6) have 91.5% and 91.8% transparency and gloss of 90.3 and 90.7 GU respectively. The thermal properties like T_g and the thermal stability of the coatings were verified using differential scanning calorimetry, and thermogravimetric analysis respectively which was found to increase with increasing EP content and decreasing AP content which may be ascribed to improved compatibility of copolymers, and homogeneity in PU along with enhanced crosslinking density. The degree of adhesion of coating with the substrate was validated from lap-shear, and cross-cut tape test which showed improved performance at AP:EP ratio of 60:40. The coatings were found to exhibit resistance toward pencil hardness with aePU-5 and aePU-6 having the optimum resistance of 9H. The surface morphology and topography were observed under scanning electron microscopy, and atomic force microscopy, respectively. The outcome confirms the higher smoothness of the surfaces subjected to the increase in EP content. The PU system with 40 wt% AP content and 60 wt% EP designated as aePU-5 was found to exhibit optimum performance.     

Advances in RAFT polymerization: the synthesis of polymers with defined end-groups

This paper provides an overview and discusses some recent developments in radical polymerization with reversible addition-fragmentation chain transfer (RAFT polymerization). Guidelines for the selection of RAFT agents are presented. The utility of the RAFT process is then illustrated with several examples of the synthesis of polymers with reactive end-groups. Thus, RAFT polymerization with appropriately designed trithiocarbonate RAFT agents is successfully applied to the synthesis of narrow polydispersity carboxy-functional poly(methyl methacrylate) and primary amino-functional polystyrene. Methods for removing the thiocarbonylthio end-group by aminolysis, reduction and thermal elimination are discussed. It is shown that the thiocarbonylthio end-group can be cleanly cleaved by radical induced reduction with tri-n-butylstannane, to leave a saturated chain end, or by thermolysis, to leave an unsaturated chain end.     

Novel curing agents: Thermal radical initiators as viable alternatives to peroxides

Stable 1-pack coating systems are gaining importance at the expense of short-potlife 2-pack formulations. Two processes can initiate the cure mechanism: the action of heat and the action of UV-light. The use of heat has traditionally been the more popular process, as UV-curing still requires some investment and process modification on the part of customers willing to enter this market. In contrast to UV-curing, thermal curing ensures homogeneous cure on large 3D surfaces, as a result of the uniform distribution of heat all over the substrate.

Thermal curing of 1-pack coating systems is usually induced by polymerization of acrylates set off by peroxide initiators. The extreme exothermic reactivity of peroxides can result in an explosion if they are stored under unsuitable conditions (temperature increase). Another major but less dangerous drawback to using peroxide-containing 1-pack systems is their tendency to gel prematurely. The coating industry is therefore increasingly demanding a safe alternative to peroxides, i.e. non-explosive thermal radical initiators that combine good thermal stability and curing at relatively low temperature.

This paper describes a novel class of curing initiators, non-peroxide thermal radical initiators (TRI), and gives details of their reactivity, stability and coating performance when they are incorporated in 1-pack acrylate functionalized coating formulations.     

Electrochemical and spectroscopic measurements for stable nitroxyl radicals

A nitroxyl radical, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), is known to be oxidized electrochemically at 3.5 V versus lithium [4] and [5]. Since this reaction is reversible in the aprotic electrolyte, we can use it as a cathode reaction in lithium rechargeable battery. Some nitroxyl radical compounds which have different structures have been prepared and their electrochemical behavior and spectroscopic properties have been studied. The electrochemical measurements in aprotic electrolyte revealed that most nitroxyl radical compounds show reversible redox behavior similar to that of TEMPO independent of their structures in the range of −0.15-0.20 V versus Ag/Ag⁺ (3.69-4.04 V versus Li/Li⁺). The redox potentials for these materials were found to be predictable approximately by quantum calculations. Thus, various molecular designs tailored to desired redox potentials would be possible as active materials for lithium rechargeable batteries, and their specific capacities, mechanical properties and colors can be controlled within limits.