PANI–LDPE composites: Effect of blending conditions

A composite based on polyaniline (PANI) and low density polyethylene (LDPE) with electrical conductivity was developed. Polyaniline was polymerized by chemical oxidation and doped with dodecyl‐benzene‐sulfonic acid (DBSA). PANI–LDPE composites were prepared via melt blending and the films were obtained by compression molding. The influence of three variables of the blending (temperature, [PANI], rotor speed) on conductivity, microstructure and mechanical properties of the composites was studied by means of statistical tools and a 2³ experimental design. The results show that the PANI concentration is the most influential variable, which mainly affects the conductivity and the elongation at break of the composites. These changes are related to the microstructure of the composites. Statistically, the other variables don't show significant influence on conductivity and mechanical properties in the studied range. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers.     

Polyaniline–nylon 6 composite nanowires prepared by emulsion polymerization and electrospinning process

Polyaniline (PANI) nanoparticles doped with the dodecylbenzene sulfonic acid (DBSA) were prepared and these nanoparticles were electrospun with nylon 6 as matrix material into fiber web. Depending on the contents and concentrations of PANI and nylon 6, either nylon 6 nanofibers (～96 nm) or PANI‐nylon 6 composite nanofibers (～12 nm) were obtained. The electrical conductivity of PANI(DBSA)–nylon 6 electrospun fiber web was lower than that of PANI(DBSA)‐nylon 6 film because of the low crystallinity of the PANI(DBSA)–nylon 6 composite electrospun fiber web. However, it showed that the PANI–nylon 6 composite nanofibers would have applications as the nanowires for connecting the microelectromechanical system (MEMS). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1277–1286, 2006     

Synergistic effect of polyaniline and multiwalled carbon nanotube on the microstructure and the electric property in PP/PANI/MWNT composites

In this article, the volume conductivity of polypropylene (PP)/polyaniline (PANI)/multiwalled carbon nanotube (MWNT) composites was detected. When the ratio of PANI protonated with dodecylbenzene sulphonic acid (PANI‐DBSA) to MWNT is 2 to 3 and 3 to 17, the volume conductivity of the two composites is much higher than that of composites filled with solely PANI‐DBSA or MWNT. The synergistic effects of PANI‐DBSA and MWNT on the microstructure and the electric property of PP/PANI/MWNT composites were carefully analyzed by scanning electron microscope (SEM) and transmission electron microscopy. The SEM results illuminate that the dispersion and the continuity of the composites filled with PANI‐DBSA and MWNT are far better than that filled with only PANI‐DBSA or MWNT. Especially, the dispersion and continuity of PP/PANI/MWNT 5, in which the ratio of PANI‐DBSA to MWNT is 3 to 17, are the best among all the composites. When PANI‐DBSA is introduced in PP/PANI/MWNT composites, the size of agglomerated particles decreases, and the dispersion of conductive particles is improved evidently. Therefore, there is a synergistic action of PANI‐DBSA and MWNT, which is used to improve the dispersion of conductive particles and the volume conductivity of the PP/PANI/MWNT composites. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Synthesis,characterization, and comparative study of conducting polyaniline/lead titanate and polyaniline–dodecylbenzenesulfonic acid/lead titanate composites

To study the effect of a surfactant on the properties of polyaniline (PANI)/metal oxide composites, PANI/lead titanate (PbTiO₃) composites were synthesized with different weight percentages (10, 20, 30, 40, and 50 wt %) of PbTiO₃ in both the absence and presence of dodecylbenzenesulfonic acid (DBSA) by the polymerization of aniline with ammonium persulfate as an initiator. The structural characteristics and stability, surface characteristics, and electric properties of PANI/PbTiO₃ and PANI–DBSA/PbTiO₃ were studied and compared. The interfacial interactions and thermal stability of these composites were characterized with X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermogravimetry techniques. The results indicate significant changes in the physicochemical properties of the composites with the incorporation of DBSA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Melt processable conducting poly(aniline‐co‐o‐anisidine)/linear low‐density polyethylene composites with ethylene‐acrylic acid copolymer as compatibilizer

Conducting composites of aniline/o‐anisidine copolymer doped by dodecylbenzenesulfonic acid (P(An‐co‐oAs)‐DBSA), linear low‐density polyethylene (LLDPE), and ethylene–acrylic acid copolymer (EAA) as compatibilizer were prepared by melt processing. The effects of composition on electrical conductivity, resistivity‐temperature characteristic, and mechanical properties were also investigated. The electrical conductivity of ternary composites markedly increased due to compatibilizition and protonation effect of the EAA. The SEM micrograph shows that the compatibility between the P(An‐co‐oAs)‐DBSA and the LLDPE matrix is enhanced after the introduction of EAA. The positive temperature coefficient of resistivity characteristic is observed. Tensile strength of P(An‐co‐oAs)‐DBSA/LLDPE/EAA composites is improved, compared with P(An‐co‐oAs)‐DBSA/LLDPE composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1511–1516, 2005     

乙烯-丙烯酸共聚物增容导电苯胺共聚物/聚乙烯共混物的形态与性能

以乙烯-丙烯酸共聚物(EAA)为增容剂,将十二烷基苯磺酸热掺杂的苯胺/邻甲氧基苯胺共聚物〔P(An-co-oAs)-DBSA〕与线性低密度聚乙烯(LLDPE)进行熔融共混制得P(An-co-oAs)-DBSA/LLDPE/EAA导电共混物,研究了EAA用量对共混物的导电性能和力学性能的影响。结果表明,当EAA与LLDPE的质量比为30/70时,共混物的电导率最佳,随着EAA含量的增加,共混物的拉伸强度增加,扯断伸长率降低;紫外-可见光谱分析表明,EAA在共混过程中对P(An-co-oAs)有一定的二次掺杂作用;扫描电子显微镜照片显示,EAA对共混体系有良好增容作用,同时发现EAA用量过多时会对P(An-co-oAs)-DBSA产生包覆作用,这对共混物的导电性是不利的。     

Electrical conductivity and rheological behavior of multiphase polymer composites containing conducting carbon black

Multiphase polymer composites of carbon black (CB), polypropylene (PP) and low density polyethylene (LDPE) were prepared by melt‐mixing method to reduce the amount of CB in the conductive composites. SEM images showed that CB preferably located in LDPE phase and formed electrically conductive path. The measurement of conductive properties showed that the ternary materials possessed lower percolation than binary composites of CB/PP or CB/LDPE, the former was ～6 wt% and the latter was 9–10 wt%. Positive temperature coefficient (PTC) effects of the binary and ternary composites were investigated, indicating that the latter exhibited a relatively high PTC intensity. A rheological percolation estimated by a power law function is 2.66 wt% of CB loading, suggesting an onset of solid‐like behavior at low frequencies. This difference between the electrical and rheological percolation thresholds may be understood in terms of the smaller CB–CB distance required for electrical conductivity as compared with that required to impede polymer mobility. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

An investigation for the effect of recycled matrix on the properties of textile waste cotton fiber reinforced (T‐FRP) composites

The main objective of this research is to study the effect of recycled low density polyethylene (r‐LDPE) matrix on the tensile, impact, and flexural properties of the novel textile waste cotton fiber reinforced (T‐FRP) composites. For this purpose, the T‐FRP composites were manufactured by using two different matrix types; namely, virgin LPDE (v‐LDPE) and r‐LDPE, with different waste cotton fiber content. All composites were compatibilized by maleic anhydride‐LDPE (MA‐LDPE) in order to increase the interfacial adhesion between fibers and matrices. Differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analyzer studies were performed in order to characterize the materials. The results have shown that best tensile and flexural properties have been obtained from the composites with the content of 30 wt% cotton fiber, 5 wt% maleic anhydride‐LDPE, and 65 wt% recycled LDPE matrix. However, the impact properties of the composites were decreased drastically compared to the pure LDPE matrix. POLYM. COMPOS., 38:1231–1240, 2017. © 2015 Society of Plastics Engineers     

Investigation on the microstructure and the electric property of poly(propylene)/chlorinated poly(propylene)/poly(aniline) composites

The article presents results of studies on composites made from poly(propylene) (PP) modified with poly(aniline) (PANI) doped with dodecylbenzene sulfonic acid (DBSA) and chlorinated poly(propylene) (CPP). The volume resistivity of PP/CPP/PANI composites was detected, and the results show that the volume resistivity decreases with increasing CPP content, and there exists a minimum volume resistivity. Effects of CPP on the microstructure and crystalline structure of the PP/CPP/PANI composites and the relationship between the effects and the electric property were carefully analyzed by scanning electron microscope (SEM) and wide angle X‐ray diffraction (WAXD). The method that the specimens of SEM are polished is appropriate to investigate the morphology of conducting polymer composites. The obtained results illuminate that the area of conducting parts and insulating parts obtained from the digital analysis of the SEM image is obviously influenced by the CPP content, the parameters of the lamellar‐like structure are immediately related to CPP content and denote the dispersion of PANI‐DBSA, and the percent crystallinity and mean crystal size of PP are directly correlated with the CPP content. The increasing area of conducting parts, the increasement of layer distance, the decreasement of size and layer number of the lamellar‐like structure of PANI‐DBSA, and the increasement of the percent crystallinity and mean crystal size of PP are beneficial to the improvement of the conductive property of PP/CPP/PANI composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Improved environmental stability,electrical and EMI shielding properties of vapor‐grown carbon fiber‐filled polyaniline‐based nanocomposite

An all polymeric electrically conductive thermoset adhesive resin system is prepared for future lightning strike protection applications. Polyaniline (PANI)‐based hybrid nano‐composite is prepared by incorporating high apparent‐density type vapor grown carbon fiber (VGCF‐H) as additional conductive filler. Electrical, mechanical and electromagnetic interference (EMI) shielding properties of PANI‐dodecylbenzene sulfonic acid (DBSA), and divinylbenzene (DVB) system are improved with addition of VGCF‐H. Different weight percentages of VGCF‐H in the PANI‐DBSA/DVB matrix, are studied, and their effect on composite's properties are investigated. Electrical conductivity up to 1.89 S/cm with the addition of 5 wt% VGCF‐H is achieved, which is almost 300% improvement compared with previous system. However, the maximum flexural modulus is obtained at 3 wt% of VGCF‐H. The change in the electronic structure of PANI with the addition of VGCF‐H is investigated using Fourier transform infrared (FT‐IR) analysis. Rheological study and Differential scanning calorimetry analysis were employed to show the effect of VGCF‐H concentration on curing profile of the nanocomposites. EMI shielding properties of the composite with and without VGCF‐H are measured in X‐band frequencies and compared. Composite with 5 wt% VGCF‐H has shown EMI shielding effectiveness about 51 dB in X‐band, which is higher than the composite without VGCF‐H (around 22 dB). POLYM. ENG. SCI., 59:956–963, 2019. © 2018 Society of Plastics Engineers     

Development of novel conducting composites of linseed‐oil‐based poly(urethane amide) with nanostructured poly(1‐naphthylamine)

Novel conducting polymer composites of linseed‐oil‐based poly(urethane amide) (LPUA) were synthesized using nanostructured poly(1‐naphthylamine) (PNA). The combination of the electrically conducting PNA with LPUA was accomplished through different weight percent loadings (0.5–2.5 wt%) of the conducting polymer. The particle size of the nanocomposite was determined using transmission electron microscopy and was found to be in the range 17–27 nm. Intermolecular hydrogen bonding between the two polymers and formation of urea linkages were confirmed by Fourier transform infrared spectroscopy. The electrical conductivity of the nanostructured conducting composites at 2.5 wt% loading was found to be comparable to that reported for polyaniline (PANI)/polyurethane at 30 wt% loading of PANI. This shows the superior properties of PNA and its potential for application in anti‐static as well as corrosion‐protective coatings. The present method of formulation of composites using an oil‐based polymer matrix is useful and economically feasible in the sense that a great variety of oil‐based polymer matrices can be used to form composites that are ecologically safe and exhibit properties similar to commercial polymers. Copyright © 2007 Society of Chemical Industry     

SEBS/PPy.DBSA blends: Preparation and evaluation of electromechanical and dynamic mechanical properties

In this study, the electromechanical and dynamic mechanical properties of electrically conducting polymer blends were investigated. The blends were comprised poly(styrene‐b‐butylene‐ran‐ethylene‐b‐styrene) (SEBS) containing polypyrrole doped with dodecylbenzenesulfonic acid (PPy.DBSA). The two types of PPy.DBSA (with and without an excess of DBSA) were blended with SEBS through the solution casting method at room temperature. The dynamic mechanical characterization of the SEBS/PPy.DBSA blends demonstrated that the use of PPy.DBSA with and without free DBSA molecules results in different degrees of interaction with the two phases of the SEBS copolymer matrix. The changes in the electrical conductivity of the blends during repeated pressure loading/unloading were investigated. The conducting SEBS/PPy.DBSA polymer blends exhibited an increase in the electrical conductivity on pressure loading and underwent a corresponding decrease on unloading. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrical and structural analysis of conductive polyaniline/polyimide blends

Conducting films of dodecylbenzenesulfonic (DBSA)‐doped polyaniline/polyimide (PANI/PI) blends with various compositions were prepared by solvent casting followed by a thermal imidization process. Electrical and physical properties of the blends were characterized by infrared spectroscopy, an X‐ray diffraction technique, thermal analysis, a UV‐vis spectrophotometer, a dielectrometer, and conductivity measurements. The blends exhibited a relatively low percolation threshold of electrical conductivity at 5 wt % PANI content and showed higher conductivity than that of pure DBSA‐doped PANI when the PANI content exceeded 20 wt %. A lower percolation threshold and a lower compatibility was shown between the two components in the blends than those of PANI–camphorsulfonic acid/polyamic acid (PANI–CSA/PAA). A well‐defined layered structure due to the alignment of the long alkyl chain dopant perpendicular to the PANI main chain was evidenced by WAXD spectra. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2169–2178, 1999     

Aliphatic–aromatic polyester–polyaniline composites: preparation,characterization, antibacterial activity and conducting properties

Poly(butylene adipate‐co‐terephthalate) (PBAT) composites containing polyaniline (PANI) were prepared using a melt blending process. Acrylic‐acid‐grafted PBAT (PBAT‐g‐AA) and PANI were used to improve the compatibility and dispersibility of PANI within the PBAT matrix. The composites were characterised morphologically using scanning electron microscopy, chemically using Fourier transform IR spectrometry and ¹³C solid‐state nuclear magnetic resonance, and optically using UV‐visible spectroscopy. The electrical conductivity of the composites was also evaluated with a resistance tester and a cyclic voltameter. Escherichia coli (BCRC 10239) was chosen as the standard bacterium for determining the antibacterial properties of the composite materials. The anti‐static properties of the composites were also evaluated. The PBAT‐g‐AA/PANI composite showed markedly enhanced antibacterial and anti‐static properties due to the formation of amide bonds by the condensation of the carboxylic acid groups of PBAT‐g‐AA with the amino groups of PANI. The optimal level of PANI was 9 wt%, as excess PANI led to separation of the two organic phases, lowering their compatibility. Copyright © 2012 Society of Chemical Industry     

Effect of dopant and oxidant on the electrochemical properties of polyaniline/graphite nanoplate composites

Optimizing the synthesis parameters of polyaniline/graphite nanoplate (PANI/GNP) composite is essential to the final electrochemical performance. Herein, the electrochemical properties of PANI/GNP composites, prepared by in situ chemical polymerization using varying amounts of different oxidants, with or without the addition of 4‐dodecylbenzenesulfonic acid (DBSA) as dopant, were investigated. Cyclic voltammetric results suggested that a stoichiometric amount of the oxidant iron chloride (FeCl₃) was beneficial to the electrochemical properties of the composites. The use of ammonium persulfate (APS) instead of FeCl₃ as oxidant largely increased the actual PANI content, conductivity and specific capacitance of the PANI/GNP composites. The dopant DBSA increased the conductivity of the PANI/GNP composites but did not show a positive effect on the electrochemical behavior. The cyclic voltammograms of the PANI/GNP composites indicated that the pseudocapacitance of PANI contributes more than the electrical double‐layer capacitance of GNP to the capacitance of the composites, while the presence of GNP plays an essential role in the rate capability of the composites. In this study, PANI/GNP (1:1) composite synthesized with an APS to aniline molar ratio of 1 showed a balanced combination of high specific capacitance (180.5 F g^?1 at 20 mV s^?1) and good rate capability (78% retention at 100 mV s^?1). © 2018 Society of Chemical Industry     

The Microcellular Injection Molding of Low-Density Polyethylene (LDPE) Composites

This paper reports the study of microcellular injection molding of low-density polyethylene- (LDPE) based composites. The effects of adding nanoclays and polymer additives in LDPE as well as rheological property of materials on the cell morphology, mechanical properties and surface properties of microcellular injection molded LDPE based composites are presented. For the microcellular injection molding process, when 3 wt% of nanoclays are added into LDPE-based polymers, the cell morphology can be significantly improved due to the nucleating effects resulting from the broad interface areas between polymer and nanoclays. Also, the addition of low melt flow LDPE into high melt flow LDPE could achieve smaller and denser bubbles in the polymer matrix than neat high melt flow LDPE.     

Assessment of mechanical performance,thermal stability and water resistance of novel conductive poly(lactic acid)/modified natural rubber blends with low loading of polyaniline

Biodegradable conductive polymer blends made from poly(lactic acid) (PLA), liquid natural rubber (LNR) and polyaniline (PANI) were prepared via a melt‐blending technique assisted by ultrasonic treatment. The effects of PANI at low loading (0.03 to 0.11 wt%) on the electrical conductivity and mechanical, thermal and physical properties of PLA/LNR/PANI blends were investigated. It was found that the mechanical properties of samples improved when PANI was introduced into PLA/LNR. Tensile results showed that the optimum loading of PANI was achieved at 0.07 wt% with an improvement of 8% in tensile strength compared to neat PLA/LNR. Although it was at low loading, the incorporation of PANI promoted an outstanding electrical conductivity to PLA/LNR blends. Thermal analysis of the PLA/LNR/PANI blends was conducted using differential scanning calorimetry and thermogravimetry. The thermal stabilities of the blends were improved markedly with the presence of PANI. Comparing to PLA/LNR, the incorporation of PANI component improved the resistance towards water absorption. Variable‐pressure scanning electron microscopy micrographs of PLA/LNR/PANI confirmed the good mixing of PANI with PLA/LNR and strong interaction networks among the PANI, PLA and LNR components. © 2018 Society of Chemical Industry     

Effect of dopant mixture on the conductivity and thermal stability of polyaniline/nomex conductive fabric

Electrically conductive polyaniline (PANI)/[poly(m‐phenylene isophthalamide)] Nomex composite fabric was prepared by in situ polymerization of aniline doped by a mixture of hydrochloride (HCl) and various sulfonic acids such as benzenesulfonic acid (BSA), sulfosalicylic acid (SSA), and dodecylbenesulfonic acid (DBSA); their effect on conductivity and physical properties were then investigated. PANI/Nomex composite fabrics doped by a mixture of protonic acids exhibited higher conductivity than those doped by other single dopants such as camphorsulfonic acid (CSA), p‐toluenesulfonic acid (TSA), BSA, SSA, and HCl. The conductivity of PANI/Nomex fabrics especially doped by a mixture of HCl and DBSA was evenly maintained up to 100°C without depression of mechanical properties of Nomex. Their conductivity was also maintained under extension of the composite fabric. In addition, electrical conductivity of PANI/Nomex fabrics was highly increased by ultrasonic treatment, which facilitated better diffusion and adsorption of aniline by cavitation and vibration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2245–2254, 2002     

DBSA掺杂聚苯胺的制备、表征及其导电性

采用过硫酸铵(APS)为氧化剂在十二烷基苯磺酸(DBSA)微胶束中化学氧化制备纳米棒状聚苯胺;DBSA既起乳化剂也起掺杂剂的作用。制备的掺杂聚苯胺用红外光谱(FTIR)、紫外光谱(UV-vis)、X-射线衍射(XRD)和扫描电镜(SEM)进行了表征;透射电镜(TEM)下首次观察到了聚苯胺的有序排列结构,晶面间距为5.99 Å。考察了掺杂剂/苯胺、氧化剂/苯胺的摩尔比和反应温度、时间等对聚苯胺电导率影响,最高电导率达到了0.72 S/cm。透射电镜怎能看到5.99     

Preparation and characterization of functionalized low density polyethylene matrix biocomposites

The incorporation of cellulosic fibers into polyethylene matrices was studied in this work, by dispersion of fluff pulp from maritime pine in a hot polymer solution, followed by co‐precipitation of the solid components by cooling at room temperature. The above method was found suitable for proper wetting and dispersion of fibers in the polymeric matrix, as compared with melt compounding. Unmodified low density polyethylene [LDPE], modified LDPE with maleic anhydride grafted linear low density polyethylene [M‐LLDPE] and a copolymer of acrylic acid and n‐butyl acrylate polyethylene [(AA/n‐BA)‐LDPE], were used as matrices for the preparation of fiber reinforced composites. The thermal properties of these composites were determined using differential scanning calorimetry and thermogravimetric analysis. The incorporation of cellulosic fibers results in a decrease of the crystallinity of the polymer matrix, as they act as inert material. In addition, the appropriate tests were run in order to determine the density and tensile properties of the composite specimens prepared by compression molding, with filler content ranging from 10 to 40% (w/w). Composites based on modified LDPE showed improved mechanical properties. The Takayanagi model, applied to predict the Young's modulus of composites, was in very good agreement with the experimental data obtained in this work. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers