Role of structural modification on the electrical properties of poly(ethylene terephthalate) irradiated with 90‐MeV carbon ion beam

Thin films of poly(ethylene terephthalate) (PET) having a thickness of 100 μm were exposed to different ion fluence of swift heavy ions of carbon in the range of 5 × 10¹¹ – 5 × 10¹³ ions/cm². The effect of ion beam on structural and electrical modification has been studied by UV/vis, FTIR, X‐ray diffraction (XRD), Differential Scanning Calorimetery (DSC), and AC electrical measurement techniques. On irradiation, a shift in absorption wavelength toward the red end of spectrum with increase of ion fluence was observed. The intensity of crystalline IR bands and main diffraction peak in XRD pattern were found to decrease with increase in ion fluence. It indicates the loss of crystallinity induced by ion‐beam irradiation. The crystallite size was found to increase on irradiation. The melting temperature (T_m) of PET films increased at a low ion dose (5.0 × 10¹² ions/cm²), while it decreased at higher ion fluence (50.0 × 10¹² ions/cm²). The dielectric constant (ε′) of PET films was increased with increase of ion fluence. The modifications brought about in the dielectric constant are correlated with chemical and molecular structural changes occurring on irradiation. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.     

Proton‐induced crosslinking of CR 6‐2 polycarbonate

CR 6‐2 polycarbonate samples were irradiated using different fluences (10¹¹–10¹⁴ ions/cm²) of 1 MeV protons. The structural modifications in the proton‐irradiated CR 6‐2 samples have been studied as a function of fluence using different characterization techniques such as X‐ray diffraction, intrinsic viscosity of the liquid samples, as a measure of the mean molecular mass, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, refractive index, color difference, and mechanical properties. The results indicate that the irradiation of CR 6‐2 detector at the fluence range 1 × 10¹²–5 × 10¹⁴ ions/cm² causes intermolecular crosslinking and allows the formation of covalent bonds between different chains, leading to a more compact structure of CR 6‐2 polymer, which resulted in an improvement in its thermal, optical, and mechanical properties. Also, this crosslinking reduces the ordering structure and increases the amorphous regions that enhance the polymer resilience. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Dielectric properties of irradiated polymer/multiwalled carbon nanotube and its amino functionalized form

The polymer/multiwalled carbon nanotube [poly(vinyl alcohol) (PVA)/carboxyethyl acrylate (CEA)]‐multiwalled carbon nanotube (MWCNT) and its amino functionalized (PVA/CEA)‐MWCNT‐NH₂ nanocomposite samples were successfully synthesized by the chemical method in the form of films. The samples were irradiated with gamma‐ray doses of 50 and 100 kGy and with ion beam fluence of 2.5 × 10¹⁸ and 3.75 × 10¹⁸ ions cm^?2. The prepared nanocomposite samples were characterized using X‐ray diffraction and thermogravimetric analysis. The X‐ray diffraction and thermogravimetric analysis confirm the existence of the chemical crosslinking occurred in the polymer compositions. The AC electrical conductivity, electrical modulus, dielectric constant, and dielectric loss in the frequency range 10²–10⁶ Hz are measured at room temperature. The electrical conductivity is increased with MWCNT doping, gamma‐irradiation, and by ion beam irradiation. A comprehensive analysis of the results revealed that dielectric properties are improved due to the induced physicochemical changes and conductive networks induced by ion beam irradiation. The behavioral effect of these embedded nanoparticles in a PVA matrix on the microstructural, dielectric, and electric properties is analyzed for possible device applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46647.     

Facile synthesis of graphene/polypyrrole 3D composite for a high‐sensitivity non‐enzymatic dopamine detection

One kind of nanocomposite consisting of graphene and polypyrrole was synthesized via a facile and mild way with the assistant of microwave irradiation. The synthesis route was embedding the polypyrrole into the graphene flakes to form a 3D structure, to achieve larger active surface and higher electro‐catalysis property. Structures and components of the composite were measured by X‐ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy. A stronger electrochemical response of electrode with modified resultant was observed in the electrochemical test. Dopamine sensor based on the composite showed a sensitivity of 363 μA mM ^?1 cm^?2, a linear range of 1 × 10^?4 M to 1 × 10^?3 M , and a detection limit of 2.3 × 10^?6 M (S/N = 3). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44840.     

Adsorption of VO2+ by poly[(tetrafluoroethylene)‐co‐(perfluorovinyl ether)] copolymer grafted with acrylic acid using γ‐irradiation

Grafted films were prepared by the reaction of acrylic acid (AAc) onto poly[(tetrafluoroethylene)‐co‐(perfluorovinyl ether)] copolymer (PFA) using γ‐irradiation by the mutual technique. The grafted copolymer was complexed with the vanadyl group, VO²⁺, in aqueous solution. The grafted copolymer–metal complexes were examined by infrared and ultraviolet spectrometry, energy‐dispersive spectroscopy (EDS) and X‐ray diffraction (XRD). The amount of vanadium in the grafted films was estimated using EDS. The thermal stability of the films was investigated through thermogravimetric and differential scanning calorimetry measurements. The degree of crystallinity of the grafted and complexed films decreased by treatment with VO²⁺ ions and also by heating at 300 °C. When heated at a temperature above 300 °C, the grafted chains degraded till they disappeared and the original polymer was almost completely separated. XRD investigation revealed that the metal oxide may be formed as a separate phase with subsequent decrease in the crystallinity of the copolymer. Furthermore, scanning electron microscope (SEM) investigation of the grafted and modified films, both unheated and heated (300 °C), showed changes in the structure and morphology. The tendency of the graft copolymer to adsorb and/or bind to VO²⁺ from aqueous solution is of promising use in the field of waste treatment of rare metals in the environment. Copyright © 2004 Society of Chemical Industry     

Phase‐dependent radiation‐resistant behavior of BaTiO3: An in situ X‐ray diffraction study

The radiation‐resistant response of BaTiO₃ in the tetragonal and rhombohedral phases on exposure to 100 MeV Ag⁷⁺ ion irradiation was investigated by in situ X‐ray diffraction (XRD) at room temperature (300 K) and low temperature (25 K), respectively. This study revealed that the BaTiO₃ in rhombohedral phase retained crystallinity up to an ion fluence of 1×10¹⁴ ions/cm², whereas tetragonal phase amorphized at much lower fluence viz. 1×10¹³ ions/cm². The in situ XRD along with Raman spectroscopy studies revealed that BaTiO₃ in rhombohedral phase is more radiation resistant than that of tetragonal phase. The density functional theory (DFT) calculations confirmed higher bond strength of rhombohedral phase as compared to tetragonal phase, which supported the experimental result of higher radiation stability of rhombohedral phase. The theoretical predictions on high‐temperature phase will be of relevance to the nuclear waste applications.     

Preparation and characterization of a solid polymer electrolyte PEO‐ENR50 (80/20)‐LiCF3SO3

The preparation and characterization of a polymer electrolyte films containing 80 wt % of poly (ethylene oxide) (PEO) and 20 wt % epoxidized natural rubber (ENR50) complexed with LiCF₃SO₃ has been reported. The ac impedance data showed good conducting properties of the solid polymer electrolyte (SPE) films. The greatest room temperature ionic conductivity of 7.5 × 10^?5 S cm^?1 was obtained at 25 wt % of LiCF₃SO₃ salt. This result has been supported by differential scanning calorimeter and X‐ray diffraction analysis. Analysis differential scanning calorimetry showed the relative percentage of crystallinity and T_m of PEO decreased with the increasing wt % of LiCF₃SO₃. Analysis with X‐ray diffraction suggested that the semicrystalline nature of PEO turned to amorphous due to the presence of LiCF₃SO₃. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Uniaxially aligned poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐bithiophene] thin films characterized by the X‐ray diffraction pole figure technique

Aligned thin films of the liquid‐crystalline polymer poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐bithiophene] were prepared, and the correlation between the optical anisotropy and the structural properties was shown. A series of samples with different thicknesses were prepared via a spin‐casting process on rubbed polyimide surfaces. The alignment of the polymer chains was obtained by a temperature treatment just below the clearing temperature. The degree of alignment was investigated with ultraviolet–visible absorption spectroscopy and in‐plane X‐ray diffraction. Independently, each technique revealed Hermans orientation functions in the range of 0.75–0.8. Surprisingly, a layer‐thickness dependence was not observed. In addition, the X‐ray diffraction pole figure technique revealed that the polymer chains were uniaxially aligned along the rubbing direction. The aligned films were in the nematic state, with the director elongated along the rubbing direction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of Au ion beam on structural,surface, optical and electrical properties of ZnO thin films prepared by RF sputtering

In the present work, ZnO thin films were irradiated with 700?keV Au⁺ ions at different fluence (1?× 10¹³, 1?× 10¹⁴, 2?× 10¹⁴ and 5?× 10¹⁴ ions/cm²). The structural, morphological, optical and electrical properties of pristine and irradiated ZnO thin films were characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscope (SEM), spectroscopy ellipsometry (SE) and four point probe technique respectively. XRD results showed that the crystallite size decreased from pristine value at the fluence 1?×?10¹³ ions/cm², with further increase of ion fluence the crystallite size also increased due to which the crystallinity of thin films improved. SEM micrographs showed acicular structures appeared on the ZnO thin film surface at high fluence of 5?×?10¹⁴ ions/cm². FTIR showed absorption band splitting due to the growth of ZnO nanostructures. The optical study revealed that the optical band gap of ZnO thin films changed from 3.08?eV (pristine) to 2.94?eV at the high fluence (5?× 10¹⁴ ions/cm²). The electrical resistivity of ZnO thin film decreases with increasing ion fluence. All the results can be attributed to localized heating effect by ions irradiation of thin films and well correlated with each other.     

Functionalization of industrial polypropylene films via the swift‐heavy‐ion‐induced grafting of glycidyl methacrylate

Swift‐silver‐ion irradiation was explored as a means of forming chemically active sites on the surface of biaxially oriented polypropylene films. The active species, formed in air, was used to induce the graft copolymerization of glycidyl methacrylate in an aqueous solution. The surface structure, crystallinity, morphology, and hydrophilicity of the grafted samples were characterized with Fourier transform infrared, UV, wide‐angle X‐ray diffraction, scanning electron microscopy, and contact‐angle measurements. Glycidyl methacrylate could be grafted onto biaxially oriented polypropylene after swift‐heavy‐ion irradiation without an additional initiator. The contact angle of the modified films decreased with the grafting percentage of glycidyl methacrylate on the polypropylene. The swift silver ions induced significant grafting only in small regions (i.e., the latent tracks) of the polymer. Furthermore, as the fluence of swift heavy ions increased beyond an optimum value, the overlapping of the latent tracks reduced the grafting yield. The observed findings could be very useful in developing an initiator‐free grafting system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

γ‐Irradiation effects on the thermal and structural characteristics of modified,grafted polypropylene

The effects of both the degree of grafting and γ irradiation on the thermal stability and structural characteristic of polypropylene‐graft‐polyvinylpyrrolidone and polypropylene‐graft‐polyvinylpyrrolidone modified with α‐cyano‐δ‐(2‐thienyl) crotononitrile were investigated. The employed techniques were thermogravimetric analysis, differential thermogravimetry, and X‐ray diffraction. The thermal stability of various polymeric substrates was investigated through the determination of the degradation temperature and activation energy of degradation. The effects of different parameters on the structural characteristics of different films were investigated through the determination of possible changes in the degree of ordering of the polymeric substrates. The results revealed that the thermal stability of the trunk polymer, grafted polymer, and polymer modified by α‐cyano‐δ‐(2‐thienyl) crotononitrile increased progressively with an increasing degree of grafting. The increase was, however, more pronounced for the sample undergoing the lowest degree of grafting. The activation energy of the thermal degradation process remained almost unchanged, and this indicated that the degradation processes of the different films followed almost the same mechanism. The γ irradiation at a dose of 60 kGy of the sulfur‐treated polymeric films [i.e., the polymeric films treated with α‐cyano‐δ‐(2‐thienyl) crotononitrile] reduced their thermal stability. This conclusion was reached by the consideration of the changes observed in the pre‐exponential factor of the Arrhenius equation due to different chemical and γ‐irradiation treatments. The degree of ordering, evidenced by X‐ray diffraction measurements of the trunk polymer, grafted polymer, and modified polymer, suffered a significant drop. This drop was much more pronounced for the sulfur‐containing polymeric materials. The observed drop in the degree of ordering of the polymeric substrates was taken as a measure of the structure collapse due to a certain treatment (degree of grafting and sulfur inclusion). The γ irradiation of the sulfur‐containing polymeric materials greatly increased their degree of ordering, which reached a value greater than that measured for the trunk polymer. Therefore, it was concluded that the thermal stability increased as the degree of ordering decreased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 506–515, 2006     

Shape‐memory polyurethanes minimally crosslinked with hydroxyl‐terminated AB2‐type hyperbranched polyurethanes

A series of shape‐memory polyurethanes based on poly(ϵ‐caprolactone) diol were prepared with novel hydroxyl‐terminated hyperbranched polyurethanes as crosslinkers and were characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, gel permeation chromatography, differential scanning calorimetry, scanning electron microscopy, wide‐angle X‐ray diffraction, dynamic mechanical analysis, tensile testing, and shape‐memory testing. The molecular weight of the soluble polymers ranged from 5.1 × 10⁴ to 29.0 × 10⁴ g/mol. The differential scanning calorimetry and wide‐angle X‐ray diffraction data indicated that when the crystallinities of the crosslinked polymers were compared to that of linear polyurethane, this parameter was improved when the crosslinker was in low quantity. The storage modulus ratios obtained from the dynamic mechanical analyses data of the crosslinked polymers were also high compared to that of the linear polyurethane. As a result, crosslinked polymers showed better shape‐memory properties compared to the linear polyurethanes. Also, the that incorporation of the hyperbranched polymer as a crosslinker into the polyurethane chain improved the thermal and mechanical properties of the polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of novel star polymer with β‐cyclodextrin core and its metal complexes

A novel star polymer with β‐cyclodextrin (β‐CD) core and polyacrylonitrile arms and its metal complexes (Cu²⁺, Zn²⁺, and Ag⁺) were synthesized and characterized by means of infrared spectra, ultraviolet, GPC, X‐ray photoelectron spectroscopy, differential scanning calorimetry, cyclic voltammetry, and electron spin resonance. The results indicate that the monomers of acrylonitrile were initiated by functionalized β‐CD. The thermal properties of star polymer were improved greatly after transitional metal ions were introduced into it. The novel star polymer metal complexes possess properties of metal ions, polymer, and β‐CD. Furthermore, it shows stable electrochemical activity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Fabrication and characterization of PEO/PPC polymer electrolyte for lithium‐ion battery

A new poly(propylene carbonate)/poly(ethylene oxide) (PEO/PPC) polymer electrolytes (PEs) have been developed by solution‐casting technique using biodegradable PPC and PEO. The morphology, structure, and thermal properties of the PEO/PPC polymer electrolytes were investigated by scanning electron microscopy, X‐ray diffraction, and differential scanning calorimetry methods. The ionic conductivity and the electrochemical stability window of the PEO/PPC polymer electrolytes were also measured. The results showed that the T_g and the crystallinity of PEO decrease, and consequently, the ionic conductivity increases because of the addition of amorphous PPC. The PEO/50%PPC/10%LiClO₄ polymer electrolyte possesses good properties such as 6.83 × 10^?5 S cm^?1 of ionic conductivity at room temperature and 4.5 V of the electrochemical stability window. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effects of temperature and comonomer content on poly(ε‐Caprolactam‐Co‐ε‐Caprolactone) copolymers properties: An evaluation of structural changes and dielectric behavior

A series poly(ε‐caprolactam‐co‐ε‐caprolactone) copolymers (PEAs) were investigated regarding the changes in the structure and characteristics in the context of the variation of temperature (in the range 173–373 K) and ε‐caprolactone content (from 0.0 to 25.0 wt%) in the comonomers mixture. Anionic copolymerization‐rotational molding combined technique was used for obtaining of these amide‐rich copolymers, semicrystalline and sensitive to the electric stimulus by polar amide groups, and potential degradable by ester units. For dielectric measurements was taken into account also the variation of frequency in the range of 10⁰–10⁶ Hz. The modifications observed by fourier transform infrared spectroscopy (FTIR), broad dielectric spectroscopy (BDS), X‐ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), scanning electron microscopy (SEM) supporting the increase/decrease of the homogeneity in the copolymers structure induced by variation of the chosen parameters. It was observed that the polymers films show Brill transition on heating. An approximately 15.0% ester residues and about 70% amide component from sample PEA20 are distributed in the “near surface” region. At low frequencies (i.e., 1 × 10⁰ Hz) the increasing of temperature over 240 K leads to a temperature dependence of ε′′. Over 280 K (at high frequency) and 300 K (at low frequency), the α relaxation is visible as a broad shoulder for all samples. The results are presented comparatively. POLYM. ENG. SCI., 59:465–477, 2019. © 2018 Society of Plastics Engineers     

Conducting composites of poly(N‐vinylcarbazole), polypyrrole,and polyaniline with 13X‐zeolite

N‐vinylcarbazole (NVC) was polymerized by 13X zeolite alone in melt (65°C) or in toluene (110°C) and a poly(N‐vinylcarbazole) (PNVC)‐13X composite was isolated. Composites of polypyrrole (PPY) and polyaniline(PANI) with 13X zeolite were prepared via polymerization of the respective monomers in the presence of dispersion of 13X zeolite in water (CuCl₂ oxidant) and in CHCl₃ (FeCl₃ oxidant) at an ambient temperature. The composites were characterized by Fourier transform infrared analyses. Scanning electron microscopic analyses of various composites indicated the formation of lumpy aggregates of irregular sizes distinct from the morphology of unmodified 13X zeolite. X‐ray diffraction analysis revealed some typical differences between the various composites, depending upon the nature of the polymer incorporated. Thermogravimetric analyses revealed the stability order as: 13X‐zeolite > polymer‐13X‐zeolite > polymer. PNVC‐13X composite was essentially a nonconductor, while PPY‐13X and PANI‐13X composites showed direct current conductivity in the order of 10^?4 S/cm in either system. However, the conductivity of PNVC‐ 13X composite could be improved to 10^?5 and 10^?6 S/cm by loading PPY and PANI, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 913–921, 2006     

Effect of plasticizers in poly(vinyl alcohol)‐based hybrid solid polymer electrolytes

Hybrid solid polymer electrolyte films consisting of poly(vinyl alcohol) (PVA), poly(methyl methacrylate) (PMMA), LiBF₄, and ethylene carbonate/propylene carbonate (EC/PC) were prepared with a solvent‐casting technique. The complexation was investigated with Fourier transform infrared and X‐ray diffraction. The ionic conductivities of the electrolyte films were determined with an alternating‐current impedance technique for various temperatures in the range of 302–373 K. The maximum conductivity value, 1.2886 × 10^?3 S/cm, was observed for a PVA–PMMA–LiBF₄–EC complex. Thermogravimetry/differential thermal analysis was performed to ascertain the thermal stability of the electrolyte with the maximum conductivity value. For an examination of the cyclic and reversible performance of the film, a cyclic voltammetry study was carried out. The surface morphology of the EC‐and PC‐based electrolytes was examined with scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2794–2800, 2003     

Effect of neutron irradiation on the structural,mechanical, and thermal properties of jute fiber

This article describes the effect of neutron irradiation on jute fiber (Corchorus olitorius). The jute fibers (4.0 tex) were irradiated by fast neutrons with an energy of 4.44 MeV at different fluences ranging from 2 × 10⁹ to 2 × 10¹³ n/cm². An important aspect of neutron irradiation is that the fast neutrons can produce dense ionization at deep levels in the materials. Structural analysis of the raw and irradiated fibers were studied by small‐angle X‐ray scattering (SAXS), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy. Thermal analysis carried out on the raw and irradiated fibers showed that the thermal stability of the fibers decreased after irradiation. The mechanical properties of the jute fibers were found to decrease after irradiation. The SAXS study showed that the average periodicity transverse to the layer decreased after irradiation, which may have been due to the shrinkage of cellulosic particles constituting the fiber. The residual compressive stress developed in the fiber after irradiation resulted in a decrease in crystallite size as supported by our XRD analysis. Observation with SEM did not indicate any change produced in the surface morphology of the fiber due to irradiation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Modifications in the structural,morphological, optical properties of Ag45Se40Te15 thin films by proton ion irradiation for optoelectronics and nonlinear applications

This current work reports the 30 keV proton ion irradiation induced structural, morphological, and optical properties change in Ag₄₅Se₄₀Te₁₅ films at different fluences. The thin films were irradiated with different ion fluences, such as 5 × 10¹⁵ ions/cm²,1 × 10¹⁶ ions/cm² and 5 × 10¹⁶ ions/cm². The electronic loss (S_e) dominates over the nuclear loss (S_n) in proton irradiation. The X-ray diffraction study shows the phase transformation from amorphous to crystalline upon ion irradiation. The Raman analysis confirms the change in chemical and vibrational bonds due to structural alterations in the films. The surface morphology has been studied by field emission scanning electron microscopy and the composition of the films has been checked by the energy dispersive X-ray analysis. The particle size increased upon the increase in ion irradiation fluence. The surface roughness of the films has been studied by atomic force microscopy. The transmission data is used to calculate the linear optical parameters. The absorption edge shifts towards the high wavelength region inferring the reduction in the optical bandgap. The linear refractive index of the films increased with ion fluence. The optical density increased at the high wavelength region while the skin depth decreased with fluence. The carrier concentration per effective mass decreased while the plasma frequency increased with proton irradiation. The nonlinearity (χ ⁽³⁾ and n₂) values increased significantly with the increase in fluences. Such kind of materials with optimization in their optical parameters are primarily essential for cutting-edge photonic, optoelectronic, and nonlinear optical applications.     

Semiconductive poly[N1,N4‐bis(thiophen‐2‐ylmethylene)benzene‐1,4‐diamine]‐nickel oxide nanocomposite based ethanol sensor

This study aims to use the conductivity of a synthetic polymer as the sensing probe for ethanol. In order to enhance the sensitivity of the sensor, a composite of the polymer and nickel oxide (NiO) nanoparticles was formed as it improved the conductivity. This composite exhibited 100 times more conductivity than the neat polymer. The semiconductive nanocomposite of poly [N¹,N⁴‐bis(thiophen‐2‐ylmethylene)benzene‐1,4‐diamine]‐nickel oxide (PBTMBDA‐NiO) was prepared by in situ chemical oxidative polymerization. The monomer was N¹,N⁴‐bis(thiophen‐2‐ylmethylene)benzene‐1,4‐diamine (BTMBDA). The monomer (BTMBDA), polymer (PBTMBDA), and NiO nanoparticles used in this study were synthesized. The monomer was prepared by refluxing together 2‐thiophene carboxaldehyde, benzene‐1,4‐diamine, and few drops of glacial acetic acid in ethanol medium for 3 h. The polymer, PBTMBDA, was formed by the chemical oxidative polymerization of BTMBDA in chloroform by FeCl₃. NiO nanoparticles were prepared by slow addition of aqueous ammonia to anhydrous nickel chloride at room temperature (28 ± 2 °C), and at a pH of 8 under constant stirring condition. The composite was formed by in situ chemical oxidative polymerization of BTMBDA in chloroform by FeCl₃ in the presence of the dispersed NiO nanoparticles. The molecular structure of BTMBDA and PBTMBDA were confirmed by nuclear magnetic resonance (NMR) (¹H, ¹³C, and Dept‐90°), Fourier transform infrared spectroscopy, and ultraviolet (UV)–visible spectroscopy. The PBTMBDA and PBTMBDA‐NiO nanocomposite were characterized by X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy analysis. The results of characterization studies indicate the strong interaction between PBTMBDA and NiO in the nanocomposite. The broadness of ¹H NMR peaks in PBTMBDA was due to the increased number of monomer units. The disappearance of the peak of α‐hydrogens on thiophene confirms the polymerization involving the fifth position of thiophene part of BTMBDA. The Fourier transform infrared spectroscopy spectra revealed that position of the characteristic peaks of the functional groups in the monomer shifted toward lower wave numbers in PBTMBDA and PBTMBDA‐NiO nanocomposite. This shifting confirms the presence of extended conjugation along the polymer backbone. Electronic spectra of these compounds showed three absorption bands corresponding to π→π*, n→π* and n→π* transitions of π electron of carbon, lone pair electrons of S, and lone pair electrons of N (imine) groups, respectively. From the Tafel plot, the exchange current density evaluated for the BTMBDA and PBTMBDA are 0.2815 × 10⁻⁸ and 1.1508 × 10⁻⁸ A cm⁻², respectively. PBTMBDA is evaluated to be a better electrode material than the BTMBDA. The X‐ray diffraction plots showed that the characteristic peak of NiO in PBTMBDA‐NiO nanocomposite suggested successful incorporation of NiO in PBTMBDA‐NiO nanocomposite. The thermogravimetric analysis revealed the improved thermal stability of the composite. Field emission scanning electron microscopy and energy‐dispersive X‐ray spectroscopy analysis confirmed the presence of the NiO in the composite. Incorporation of nickel oxide nanoparticles improved the electrical conductivity and stability of PBTMBDA. The conductivity of the polymer was found to be of the order of 10⁻⁵ S cm⁻¹ while that of the composite was of the order of 10⁻³ S cm⁻¹. The nanocomposite was found to be thermally more stable than PBTMBDA and exhibited better direct‐current electrical conductivity and isothermal stability than the PBTMBDA as revealed by the four‐probe study. The electrical conductivity as inferred from the four‐probe method was used as the parameter to study the isothermal stability of the composite. The PBTMBDA‐NiO nanocomposite based vapor sensor was constructed for the sensing of ethanol vapor in commercial ethanol and real samples (alcoholic drinks: Beer, Wine, Brandy, Vodka, Whisky, and Rum) It was observed that on exposure to ethanol vapor at ambient temperature, the electrical resistivity of the nanocomposite increased indicating suppression of charge carriers. The interaction of ethanol vapor with PBTMBDA in PBTMBDA‐NiO nanocomposite was confirmed by IR spectral technique. The change in the structure of the PBTMBDA on interaction with ethanol was highlighted by the changes in the infrared spectrum. The conductivity of the polymer was explained using the structure‐activity relationship of the monomer evaluated using Gaussian 09 software. This study also analyzed the total electron density with electrostatic potential of the monomer and its correlation with chemical reactivity in order to explain the ethanol vapor sensing‐property of the nanocomposite. A new method of ethanol vapor sensing by a conducting polymer composite is hereby reported. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45918.