Undoped polyaniline–surfactant complex for corrosion prevention

Due to the strict regulations on the usage of heavy metals as the additives in the coating industries, the search for effective organic corrosion inhibitors in replacement of metal additives has become essential. Electrically conducting polymers have been shown to be effective for corrosion prevention, but the poor solubility of these intractable polymers has been a problem. We have explored a polyaniline–4-dodecylphenol complex (PANi–DDPh) to improve the dissolution, and it has been shown to be an effective organic corrosion inhibitor. With the surfactant, DDPh, PANi could be diluted into the coatings, and the properties of the coatings were affected. An emeraldine base (EB) form of PANi was also found to be oxidized by the hardener. The oxidized form of polyaniline provides improved corrosion protection of metals than that of emeraldine base since the value of the standard electrode potential for the oxidized form of PANi is higher than that of EB. Additionally, the surfactant improves the wet adhesion property between the coating and the metal surface. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2849–2856, 1999     

Synthesis and characterization of polyaniline–organoclay nanocomposites

Polyaniline (PANI)–organoclay nanocomposites were prepared. Intercalation of aniline monomer into montmorillonite (MMT) modified by polyoxyalkylene was followed by subsequent oxidative polymerization of the aniline in the interlayer spacing. The organoclay was prepared by cation exchange process between sodium cation in MMT and onium ion in four different types of polyoxyalkylene diamine and triamine with different molecular weight. Infrared spectra confirm the electrostatic interaction between the positively charged onium group (NH₃⁺) and the negatively charged surface of MMT. X‐ray diffraction analysis provides a structural information. The absence of d₀₀₁ diffraction band in the nanocomposites was observed at certain types and contents of organoclay. Scanning electron microscopy and transmission electron microscopy were employed to determine the dispersion of the clay into PANI. The thermal degradation behavior of PANI in the nanocomposites has been investigated by thermogravimetric analysis. The weight loss suggests that the PANI chains in the nanocomposites are more thermally stable than pristine PANI. This improvement is attributed to the presence of nanolayers with high aspect ratio acting as barriers, thus shielding the diffusion of degraded PANI from the nanocomposites. The electrical conductivity of the nanocomposites was increased 30 times more than that of pure MMT at a certain concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of conductive polyaniline‐sulfonated EPDM ionomer composites from in situ emulsion polymerization and study of their properties

The composites of polyaniline (PAn) and zinc sulfonated ethylene–propylene–diene rubber (EPDM) ionomer were made by polymerization of aniline in the presence of the ionomer by using a direct, one‐step in situ emulsion polymerization technique. The ionomers were prepared by sulfonation of EPDM rubber with acetyl sulfate in petroleum ether, followed by neutralization with zinc acetate solution. The ionomers with sulfonate contents of 10, 24, and 42 mmol SO₃H/100 g were used for preparation of PAn/ionomer composites. The in situ polymerization of aniline was carried out in an emulsion comprising water and xylene containing the ionomer in the presence of dodecyl benzene sulfonic acid, acting as both a surfactant and a dopant for PAn. The composite was characterized by IR and WAXD. The composite obtained can be processed by melt method. The conductivity of the composite with lower sulfonate content was higher than that with higher sulfonate content. Conductivity of the composites exhibits a percolation threshold at about 13 wt % PAn. When the sulfonated content is 10 or 24 mmol SO₃H/100 g and PAn content is 4–10 wt %, the composites behave as a thermoplastic elastomers with high ultimate elongation and low permanent set. The conductivity of the composite after secondary doping with m‐cresol is higher than the composite before secondary doping by about one order. Addition of zinc stearate as an ionic plasticizer lowers both the conductivity and the mechanical strength of the composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2211–2217, 2004     

Synthesis and structure of polymethylsilsesquioxane–clay nanocomposite via in situ intercalative polymerization

Polymethylsilsesquioxane (PMSQ)–montmorillonite (MMT) nanocomposites were prepared by in situ intercalative polymerization. The dispersion of the MMT layers within the matrix was verified by X‐ray diffraction and transmission electron microscopy, which revealed an intercalated morphology with layer spacing of 3.42 nm. The layer spacing was not increased after annealing at 150°C for 3 h. The reason for this result is explained in light of the molecular structure of PMSQ synthesized in and out of the nanoconfined environment. The coherent order of the silicate layer was decreased after the annealing, possibly because of the change in the PMSQ molecule during the annealing process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3708–3711, 2002     

Plasma polymerization of random polyaniline–polypyrrole– iodine copolymers

This work presents the synthesis by plasma and the characterization of polypyrrole–polyaniline–iodine copolymer thin films. The objective was to study the conditions to randomly copolymerize different and noncombinable monomers to create new copolymers with enhanced selective properties. The study was focused on the influence of the monomer mass ratio r on the structure of the copolymers. The monomer ratio r is important since it represents the contribution of each monomer to the structure and to the properties of the copolymer. The mainstream techniques used to characterize the plasma polymers were infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The electric conductivity was studied as a function of the relative humidity. The results indicated that the copolymers with iodine have better conductive properties at lower relative humidity and that the copolymers without iodine are more stable at moderately high temperatures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 263–270, 2002     

Interfacial polymerization of polyaniline and its layer‐by‐layer assembly into polyelectrolytes multilayer thin‐films

The layer‐by‐layer (LbL) self assembly deposition technique was used to prepare multilayer thin films of anionic polyaniline‐blend‐poly(sodium 4‐styrenesulfonate) (PANI‐PSS) and cationic poly(diallydimethylammonium chloride) (PDADMAC). Anionic polyaniline was prepared by the interfacial polymerization of aniline monomer in the presence of PSS which acted as template to provide water solubility. The PSS to PANI concentration ratios used in the synthesis step was found to have a major effect on the final PANI‐PSS synthesis, its self assembly and the electrical properties of the prepared films. The optical and electrical properties of the films were measured by ultraviolet‐visible spectroscopy (UV‐Vis) and a 4‐point probe setup, respectively while the thickness of the films was measured by atomic force microscopy (AFM). Results showed that the optimum condition for the film growth and optimal conductivity were obtained with different synthesis conditions. These results suggest that the PSS concentration used for interfacial synthesis of PANI must be finely tuned depending on the type of application aimed by the user. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

反相微乳液聚合法合成聚苯胺

以环已烷为溶剂,十二烷基硫酸钠(SDS)为乳化剂,H<,2>O<,2>为氧化剂,过硫酸钾(KPS)为引发剂,浓盐酸使苯胺质子化,采用反相微乳液聚合法合成聚苯胺.研究了SDS,KPS,浓盐酸,反应时间对聚苯胺产量的影响,用循环伏安法、差热分析法对聚苯胺进行了表征.结果表明,较佳的工艺条件:SDS用量为0.50 g,KPS...     

Fabrication of DBSA‐doped polyaniline nanorods by interfacial polymerization

An interfacial polymerization was used to fabricate dodecybenzenesulfonic acid (DBSA)‐doped polyaniline (DBSA‐PANI) nanorods with diameter range from 40 nm to 1 μm. The molar ratio of aniline to ammonium peroxydisulfate (APS), the concentrations of DBSA and reaction temperature had an effect on the morphology and size of products. It was found that lower concentration of DBSA and lower temperature will be helpful to the formation of rod‐like PANI nanostructures with a relative small diameter. UV–vis and FTIR measurements were used to characterize the chemical structure of the obtained samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

PEC生物微胶囊研究进展

聚电解质复合物(PEC)生物微胶囊由聚合物阴阳离子络合反应形成,因其反应温和、生物相容性好,近年来已成为热门的研究领域,在人工器官、医疗诊断、细胞固定化等方面有着广泛的用途。本文系统介绍了PEC生物微胶囊的制备、特性研究和应用研究,并综述了这3个方面的最新研究进展,最后对PEC生物微胶囊的发展前景进行了展望。     

界面聚合法PI/PP耐溶剂复合纳滤膜的制备与表征

以丙烯酰胺接枝的聚丙烯(PP)超滤膜为支撑层,间苯二胺(MPD)、均苯四甲酰氯(BTAC)分别为水相及有机相功能单体,通过界面聚合及其后续的酰亚胺化制备了聚酰亚胺(PI)/PP耐溶剂复合纳滤膜。讨论了水相浓度、有机相浓度及酰亚胺化溶液配方等条件对复合膜结构及其分离性能的影响。分别采用傅里叶红外光谱仪(FTIR)、扫描电子显微镜(SEM)表征分离层的化学组成及复合膜的形态结构,得到膜的分离、透过及其耐溶剂性能。结果表明,有机相浓度的影响最为显著,支撑膜表面形成了均匀致密的PI分离层,复合膜呈负电性,并具备优秀的耐溶剂性能。实验范围内,MPD、BTAC的浓度分别为8、2 g·L-1,酰亚胺化溶液乙酸酐∶三乙胺∶苯体积比为1∶1∶10时,所制备膜的分离性能较佳,对Na2SO4、酸性艳蓝6B的截留率分别达93.8%和96.9%。     

纳米聚苯胺改性聚哌嗪酰胺纳滤膜的制备

以导电态纳米聚苯胺(PANI)为添加剂, 哌嗪和均苯三甲酰氯(TMC)为反应单体, 通过界面聚合反应在聚砜超滤膜上形成复合层制备纳滤膜。采用扫描电子显微镜(SEM)和原子力显微镜(AFM)等对复合膜的性能和结构分别进行了测试和表征。SEM照片证实PANI含量低时, 可以在复合膜上分布得比较均匀;AFM图像看出膜表面粗糙度的增加;膜性能的测试结果证实了添加PANI的复合膜水通量得到了提高, 同时脱盐率也有变化。最优实验条件下, 膜对Na₂SO₄、MgSO₄、MgCl₂和NaCl的截留率分别为99.4%、98.5%、85.4%和59.2%。试验结果表明, 加入PANI能够提高膜的水通量, 并提升了膜的脱盐性能。     

制备聚酰胺复合膜中界面聚合反应添加剂研究进展

聚酰胺复合膜以其优良的稳定性及良好的分离选择性成为水处理和化工分离领域应用范围最广的分离材料之一。聚酰胺复合膜一般采用界面聚合法制备,由于界面聚合反应活性高、反应参数多,致使界面层结构难以控制,膜的渗透性或选择性不理想。因此,如何有效调控膜结构,实现膜的高渗透性或选择性是目前面临的重要挑战。近期诸多研究表明,在水相或有机相中引入添加剂可以改变油水界面张力进而调控单体界面扩散速率及界面分布,或通过改变反应机理影响聚合反应速率,最终实现对界面层结构和膜性能的调控。本文从添加剂种类、性质和调控作用等角度总结了近年来添加剂对复合膜结构及性能调控的研究进展,分析了现有研究存在的问题,并建议从微观层面探究界面过程的物理化学性质以及开发高时间分辨率原位表征方法等。     

Intercalated polyaniline–kaolinite nanocomposite prepared via in situ mechanochemical synthesis

The in situ polymerization of aniline monomers within kaolinite interlayers easily led to an intercalated polyaniline (PANI)–kaolinite nanocomposite through a facile mechanochemical method. The X‐ray diffraction results demonstrate that PANI was successfully intercalated in the interlayers of kaolinite, which was lightened by an increased basal spacing from 7.24 to 14.67 Å of kaolinite in the as‐synthesized nanocomposite, and the characterization results from Fourier transform infrared spectrometry, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy further confirm this conclusion. The thermal stability of PANI was improved significantly when PANI was intercalated into kaolinite to form the nanocomposite; this was proven by thermogravimetric analysis. Moreover, a panel experiment was carried out under a simulated marine environment to evaluate the anticorrosive effect of the as‐prepared product, and the results show that the epoxy resin/intercalated PANI–kaolinite nanocomposite coating had a better anticorrosive effect than that of the neat epoxy resin coating. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43551.     

水介质中表面引发ATRP法合成PMAA聚电解质刷

水介质中以表面引发ATRP法在单分散的二氧化硅微球表面接枝了一层PMMA聚合物刷,然后通过水解得到PMAA聚电解质刷。通过控制ATRP的反应时间得到了不同分子量且分子量分布较窄的聚电解质刷。结果表明,接枝硅烷偶联剂APTES的最佳反应方式为静置反应,对于1 g微球最佳接枝量为4 mL,聚电解质刷的分子量随ATRP反应时间增长而增大。     

Synthesis by in situ chemical oxidative polymerization and characterization of polyaniline/iron oxide nanoparticle composite

Polyaniline (PANI) is a well‐studied material and is the pre‐eminent electrically conducting organic polymer with the potential for a variety of applications such as in batteries, microelectronics displays, antistatic coatings, electromagnetic shielding materials, sensors and actuators. Its good environmental as well as thermal stability and electrical conductivity tunable by appropriate doping make PANI an ideal active material for several applications. In this paper, we report the synthesis of water‐dispersible colloidal PANI/iron oxide composite nanoparticles using an in situ chemical oxidation polymerization method in a micellar medium of sodium dodecylsulfate, where the cores (iron oxide) are embedded in a PANI matrix layer. Transmission electron micrographs showed evidence of the formation of an iron oxide core/PANI shell composite with a thin layer of PANI over the iron oxide cores. The results of thermogravimetric, Fourier transform infrared and UV‐visible analysis indicated that the iron oxide nanoparticles could improve the composite thermal stability possibly due to the interaction between iron oxide particles and PANI backbone. We believe that the synthetic route described can also be adapted for the assembly of hierarchical structures of other metal oxides or hydroxides onto various cores. Copyright © 2010 Society of Chemical Industry     

Synthesis of conducting polyaniline/TiO2 composite nanofibres by one‐step in situ polymerization method

Conducting polyaniline (PANI)/titanium dioxide (TiO₂) composite nanofibres with an average diameter of 80–100 nm were prepared by one‐step in situ polymerization method in the presence of anatase nano‐TiO₂ particles, and were characterized via Fourier‐transform infrared spectra, UV/vis spectra, wide‐angle X‐ray diffraction, thermogravimetric analysis, and transmission electron microscopy, as well as conductivity and cyclic voltammetry. The formation mechanism of PANI/TiO₂ composite nanofibres was also discussed. This composite contained ～ 65% conducting PANI by mass, with a conductivity of 1.42 S cm^?1 at 25°C, and the conductivity of control PANI was 2.4 S cm^?1 at 25°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and characterization of hyperbranched cationic polyelectrolytes via aqueous self‐condensing atom transfer radical polymerization

The hyperbranched cationic polyelectrolytes (PDMEAB) were directly prepared via the CuBr/ligand‐catalyzed (ligand = 2,2′‐bipyridine or pentamethyldiethylenetriamine) aqueous self‐condensing atom transfer radical polymerization (SCATRP) of a novel inimer, N,N‐dimethyl‐N‐(2‐methacryloyloxy)ethyl‐N‐(2‐bromoisobutyryloxy)ethyl ammonium bromide (DMEAB). Elemental analysis and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of DMEAB. The hyperbranched architecture and number‐average degree of polymerization (DP_n) of the PDMEAB was studied by ¹H‐ and ¹³C‐NMR. The kinetic results suggested that the DP_n of the hyperbranched PDMEAB grew gradually in the initial stage and exponentially in the later stage. The differential scanning calorimetry (DSC) showed that the glass transition temperature of the hyperbranched PDMEAB was much lower than that of the linear analogue. The solution rheometry showed that the aqueous PDMEAB solutions approximately underwent a Newtonian behavior and their shear viscosity maintained almost constant upon the addition of NaCl because of the spherical conformations of the hyperbranched cationic polyelectrolytes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of chitosan/poly(acrylic acid) polyelectrolyte complex

Polyelectrolyte complex based on chitosan and acrylic acid monomer by photoinitiated free‐radical polymerization in the absence of crosslinker showed a large transition in swelling in response to changes in pH of surrounding medium. Their ability to swell arises from polyelectrolyte interactions and molecular structure of the complex. The main properties of interest that related to the molecular structure, swelling volumes, glass transition temperature, and elastic modulus of the complex were investigated. The effect of water content, the only variable in the sample component, played an important role in molecular structure of the complex and as a consequence, the extent of intermolecular linkage, especially amide bonds which in turn governed the degree of swelling of the polyelectrolyte complex in this study. The decreased degree of swelling and higher temperature shift of glass transition temperature was found with increased water content, whereas increased modulus of elasticity of dry complex was found in lower water content of synthesis component. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1025–1035, 2002     

Catalytic template assisted interfacial polymerization for high-performance acid-resistant membrane preparation

Highly permeable acid-resistant nanofiltration (NF) membranes are of critical significance for the efficient treatment of acidic streams. Enhancing permeability while maintaining the high solute rejection of acid-resistant NF membranes remains a great challenge due to the low reactivity of monomers. In this work, a novel catalytic template assisted interfacial polymerization (IP) strategy of 3-aminobenzenesulfonamide (ABSA) and trimesoyl chloride (TMC) was provided to prepare a poly(amide-sulfonamide) membrane. Aminopyridine doped graphene quantum dots rich in acylation catalytic sites and ZIF-8 nanoparticles are co-loaded on a substrate as template. Benefiting from the enhanced phase integrity and self-inhibition effect of the template assisted IP process, the resulting ultra-thin acid-resistant membrane exhibits an excellent water permeance (20.4 Lm⁻²h⁻¹bar⁻¹) with a high Na₂SO₄ rejection of 90.5%, which outperforms almost all the reported acid-resistant NF membranes. Our work paves a versatile way for synthesis of special separation membranes.     

Electrorheological effects of polyaniline‐type electrorheological fluids

Three kinds of particles—polyaniline (PANI), poly(o‐toludine) (POT), and brominated polyaniline (Br‐PANI)—were synthesized. With chlorinated paraffin as a disperse oil, their electrorheological (ER) effects were determined so that the influence of the phenyl substitute group on the ER effects could be considered. POT exhibited the strongest ER effect, whereas the Br‐PANI ER effect was relatively poor. With the concept of polarization, this phenomenon was interpreted. The influence of the antidoping condition on the ER effects was also examined. An optimal antidoping condition was found for each kind of particle. Composite PANI/polyacrylamide (PAAm) and PANI/lithium polyacrylate (PAA‐Li) particles were further prepared by emulsion polymerization. The testing results showed that the composite particles with certain amounts of PAAm or PAA‐Li exhibited good ER effects. The dielectric and conductive behaviors were also determined so that the results could be explained. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 733–740, 2003