Diaminodiphenyl Ether Research Articles

COMPOSITE MATERIALS BASED ON ALICYCLIC COPOLYIMIDE AND ACRYLIC ACID COPOLYMER WITH ACRYLAMIDE

Progress in polymer materials science is mainly associated with the development of new composite materials, created by the introduction of modifying additives into the matrix polymer which which improve polymer characteristics due to their properties. The purpose of this work is to obtain composite materials with improved thermal and mechanical properties from copolyimide based on dianhydrides of tricyclotetracarboxylic and diphenyloxydtetracarboxylic acids with diaminodiphenyl ether modified by a copolymer of acrylic acid with acrylamide. Results and discussion. Polymer compositions of copolyimides of arylalycyclic structure in combination with acrylic acid copolymer and acrylamide, as well as composite materials (film) based on them, were obtained. It was found that with an increase in the content of the added component from 0.35 to 2.0 wt%, uniformity is maintained in the polymer mixture. The infrared (IR) spectroscopy method shows that during formation of the above polymer mixtures the interaction of functional groups of the polymers under study with the formation of hydrogen bonds, which determine the homogeneity of the mixture. By methods of thermogravimetry and stretching of the sample with a constant deformation rate were used to determine, respectively, the thermal resistance and mechanical properties of the developed composite films. The increase of thermal resistance and strength of the film is explained by the formation of partial intermolecular cross-linking between the components of the mixture and the elasticity of the material – with the plasticizing effect of the additive. Conclusion. Polymer mixtures were obtained and composite films were molded on their basis.

Effects of different amine-functionalized graphene oxide on the mechanical and thermal properties of polyimide composites

The utilization of functionalized graphene oxide as nanofillers has attracted significant attention in the development of high-performance composite materials. In this study, amine-functionalized graphene oxide (AFGO) by different amines, including p-phenylenediamine- (PPD-GO) and 4, 4’-diaminodiphenyl ether (ODA-GO), respectively, was prepared and used to synthesize a series of polyimide (PI) composite membranes via in situ polymerization method. The PPD-GO/PI and ODA-GO/PI composite membranes exhibited much higher mechanical and thermal properties than that of neat PI, owing to the diverse interfacial interaction and the surface architecture behavior. Compared to neat PI, the tensile strengths were enhanced 14.6% and 14.5%, the tensile modulus were enhanced 26.9% and 23.2%, and the Tg increased by 9°C and 17.5°C of the PI composite membrane containing 0.3 wt% PPD-GO or ODA-GO, respectively. This study provides a guidance for the development of high-performance PI composite materials through the regulated interfacial structure via the moderate chain length.

Structure and properties of thermoplastic polyimide based on 4′, 4′—(Oxybis (methylene)) bis ([1.1′- bipheny]3-amine) diamine

In this work, a new diamine was designed by connecting flexible structures such as ether bond and aliphatic carbon chain between benzene rings, and was synthesized and purified through simple reactions such as Suzuki reaction. Finally, a series of polyimide (PI) films were synthesized by copolymerization with 4.4`-diaminodiphenyl ether (ODA)\pyromellitic dianhydride (PMDA) in different proportions. We prepared polyimide films with new monomer copolymerization ratios of 1% (PI-1), 5% (PI-2), 10% (PI-3), and 20% (PI-4). The polyimide films showed excellent glass transition temperatures, which were attributed to their unique bent architectures. The mechanical and thermal properties of the thermosets were studied using tensile testing, static thermomechanical analysis (TMA), and thermogravimetric analysis (TGA). As the results, the films exhibited the optimal glass transition temperatures (317.56°C–381.91°C), and the component with the highest copolymerization ratio has a 15% decrease in glass transition temperature compared to the component without copolymerization. Moreover, PI-1-PI-4 showed good heat resistance in the N2 atmosphere. The temperatures corresponding to a 5% heat loss in the films (T5%) were 458.12 °C–548.75°C, respectively.

Preparation and Properties Magnetite/Polyimide Composites

To make the polyimide (PI) composite material having both heat resistance and magnetic permeability, Fe3O4/PI magnetic polyimide composite powder was synthesized by one-step solvothermal method. 4,4'-diaminodiphenyl ether (ODA) as monomers, ether anhydride polyamic acid (PAA) was designed and prepared by Fe3+ and polyimide precursor-polyamic acid triethylamine salt (PAAS) was reacted in a reactor, and the PI/Fe3O4 composite powders were synthesized under the condition of high temperature and high pressure. The obtained PI/Fe3O4 composite powders were analyzed by infrared spectroscopy, microscopic morphology and thermal properties. The morphology and structure of the samples were both characterized by scanning electron microscopy (SEM) and infrared spectroscopy (IR). The thermal properties of the composite microspheres were studied via thermogravimetric analysis (TGA) and the magnetic properties were determined by a vibrating sample magnetometer (VSM). The saturation magnetization decreases gradually, increasing the polyimide content, with a saturation magnetization of PI/Fe3O4 determined to be 20.29 emu/g.

Construction of a Bis(benzene sulfonyl)imide-Based Single-ion Polymer Artificial Layer for a Steady Lithium Metal Anode.

Dendrite growth and parasitic reactions with liquid electrolyte are the two key factors that restrict the practical application of the lithium metal anode. Herein, a bis(benzene sulfonyl)imide based single-ion polymer artificial layer for a lithium metal anode is successfully constructed, which is prepared via blending the as-prepared copolymer of lithiated 4, 4'-dicarboxyl bis(benzene sulfonyl)imide and 4,4'-diaminodiphenyl ether on the surface of lithium foil. This single-ion polymer artificial layer enables compact structure with unique continuous aggregated Li+ clusters, thus reducing the direct contact between lithium metal and electrolyte simultaneously, ensuring Li+ transport is fast and homogeneous. Based on which, the coulombic efficiency of the Li|Cu half-cell is effectively improved, and the cycle stability of the Li|Li symmetric cell can be prolonged from 160 h to 240 h. Surficial morphology and elemental valence analysis confirm that the bis(benzene sulfonyl)imide based single-ion polymer artificial layer effectively facilitates the Li+ uniform deposition and suppresses parasitic reactions between lithium metal anode and liquid electrolyte in the LFP|Li full-cell. This strategy provides a new perspective to achieve a steady lithium metal anode, which can be a promising candidate in practical applications.

High-Performance Reversible Furan-Maleimide Resins Based on Furfuryl Glycidyl Ether and Bismaleimides.

Two reversible furan-maleimide resins, in which there are rigid -Ph-CH2-Ph- structures and flexible -(CH2)6- structures in bismaleimides, were synthesized from furfuryl glycidyl ethers (FGE), 4,4'-diaminodiphenyl ether (ODA), N,N'-4,4'-diphenylmethane-bismaleimide (DBMI), and N,N'-hexamethylene-bismaleimide (HBMI). The structures of the resins were confirmed using Fourier transform infrared analysis, and the thermoreversibility was evidenced using differential scanning calorimetry (DSC) analysis, as well as the sol-gel transformation process. Mechanical properties and recyclability of the resins were preliminarily evaluated using the flexural test. The results show the Diels-Alder (DA) reaction occurs at about 90 °C and the reversible DA reaction occurs at 130-140 °C for the furan-maleimide resin. Thermally reversible furan-maleimide resins have high mechanical properties. The flexural strength of cured FGE-ODA-HBMI resin arrives at 141 MPa. The resins have a repair efficiency of over 75%. After being hot-pressed three times, two resins display flexural strength higher than 80 MPa.

Synergistic effect of phenyl phosphoric acid derivatives and DOPO on multifunctional epoxy resin: Fire safety, mechanical properties, transparency and hydrophobicity

A novel reactive flame retardant named PPDA was synthesized by neutralizing phenyl phosphate (PPOA) with 4,4′-diamino diphenyl ether (ODA). When 2.5 wt% of PPDA was incorporated into epoxy resin (EP) alongside 2.5 wt% of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), EP/PPDA/DOPO composite possessed UL-94 V-0 rating and a limited oxygen index (LOI) of 34.2% while exhibiting a remarkable synergistic effect between PPDA and DOPO. In contrast to pure EP, EP/PPDA2.5/DOPO2.5 exhibited a significant reduction in peak heat release rate, total heat release, and total smoke production by 56.3%, 23.0%, and 26%, respectively, when increasing char yield to 30.2%. The synergistic system formed char with organic phosphorus structures containing P-O-C, P-N-C, and P=O bonds, along with benzene rings in the condensed phase, meanwhile forming P-containing radicals and non-flammable nitrogen-containing compounds in the gas stage. Additionally, it was discovered that the presence of the NH bond in PPDA and the P-H bond in DOPO facilitated the ring-opening reaction of the epoxy groups, which contributed to the preservation of the mechanical properties and transparency of the EP. PPDA/DOPO was a halogen-free, low-cost alternative for flame retardants, demonstrating excellent performance and potential for future applications.

Soluble imide oligomers containing benzoxazole structures

A series of soluble thermosetting polyimide resins containing benzoxazole structure were synthesized by two-step polymerization using 4-phenylethynylphthalic anhydride (4-PEPA) as the end-capping reagent, 2-(4-aminophenyl)-5-aminobenzoxazole (BOA) and 3,4′-diaminodiphenyl ether (3,4′-ODA) as the aromatic diamines, and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) as the aromatic dianhydride. The imide oligomers were characterized by employing Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), solubility tests and rheological measurements. Thermosetting polyimides derived from the imide oligomers were then produced via a thermal cross-linking reaction of the phenylethynyl group. The thermal and mechanical properties of the thermosets were studied using thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA), and mechanical property measurements. The effects of chemical architectures and molecular weights of the imide oligomers on processability, thermostability and mechanical properties were systematically investigated. The results showed that all the copolymerized imide oligomers possessed good solubility in organic and low melt viscosity, and the corresponding thermosets exhibited high glass transition temperature (up to 401°C) and 5% weight-loss temperature (up to 533°C) in an air atmosphere while excellent mechanical properties (flexural strength up to 217 MPa and elongation at break up to 11.2%). With the increase of the concentration of the benzoxazole group, the imide oligomers of PI-X-2 (-O-, -BO-, -B-) exhibited less solubility and higher minimum melt viscosity but improved glass transition temperature after curing and mechanical properties of their thermosets.

ВЛИЯНИЕ СОСТАВА ПЕНООБРАЗУЮЩЕЙ КОМПОЗИЦИИ НА ТЕРМИЧЕСКИЕ И МЕХАНИЧЕСКИЕ СВОЙСТВА ОБРАЗУЮЩИХСЯ ПЕНОПОЛИИМИДОВ

Foaming prepolymer compositions based on 4,4'-diphenyloxytetracarboxylic acid dianhydride ethyl ester, 4,4'-diaminodiphenyl ether, 1,6-hexamethylenediamine and surfactant are synthesized. The structure of the synthesized compounds is confirmed by the IR spectroscopy; the data of scanning electron microscopy of samples of the formed foam materials are presented. The influence of the components of the foaming composition (surfactant and aliphatic diamine) on the structure, thermal and mechanical properties of the resulting polyimide foams is traced. The possibility of controlling the pore sizes in the foam material by selecting different fractions (250-400 μm) of particles of a powdered foam composition for heat treatment has been shown. The resulting foams have high thermal stability (the onset of weight loss is observed in the range of 470-499 °C); their density varies from 7.57 to 16.60 kg/m3; Young's modulus in compression is in a range of 200-270 kPa, stress at fracture lies within the range from 6.47 to 17.77 kPa

High temperature phenylethynyl-terminated imide oligomers derived from asymmetric diphenyl ether diamines for resin transfer molding

Resin transfer molding (RTM) require phenylethynyl-terminated imide oligomers (PETIs) to exhibit low melt temperatures and better melt stability. To decrease the melt temperatures of PETIs and improve their resin transfer moldable processability, asymmetric 4,4′-diaminodiphenyl ether substituted by fluorine (F-ODA), trifluoromethyl group (3F-ODA) or phenyl group (p-ODA) were introduced. Asymmetric molecular structure and substituent groups decrease the melt temperatures of PETIs, endowing PETIs with the wider processing temperature windows and low minimum melt viscosity (<1 Pa s). These polyimides show pot lives of 30–60 min at 260–280 °C. Furthermore, the effects of backbone structure on melt fluidity of imide oligomers were discussed by the calculation of viscous activation energy (Ea,η) and analysis of Molecular Dynamics. PETI-3F and PETI-P based on 3F-ODA and p-ODA exhibit low and stable melt viscosities (<1 Pa s) at 250–270 °C and 260–270 °C for 4 h respectively, enabling the successful fabrication of carbon fiber reinforced polyimide composites via RTM process. After cured at 380 °C, the thermosets of PETI-3 and PETI-4 show high Tg of 412 °C and 402 °C and good thermal stability (Td5>550 °C). Cured PETI-3 and PETI-4 also show good mechanical properties (tensile strength >50 MPa). In comparison with p-ODA, 3F-ODA could provide PETIs with superior resin transfer moldable processability and higher heat-resistance and is more suitable to synthesize PETIs for RTM application, because of better balance between polymer segmental mobility and polymer chain packing.

Curing and thermal comparative study of rosin epoxy thermosets with bio-based imidoamines and commercial curing agents

This paper includes the curing of previously synthesized multifunctional bio-based epoxy resins (PEMPAE/TMPAE) with rosin-based imidoamine curing agents (IAMDK/IASDK/IAEDK) which are nucleophilic addition reaction products of diamino diphenyl ether (DDE) and dimaleopimaryl ketone (DMPK), a dehydrodecarboxylated derivative of MPA. Curing dynamics of rosin-based epoxy resins (PEMPAE/TMPAE) with rosin-based imidoamine curing agents (IAMDK/IASDK/IAEDK) were evaluated using differential scanning calorimetry. For comparison, the bio-based epoxy resins were also cured with rosin derivative dimaleopimaryl ketone (DMPK) and commercial-based diamino diphenyl ether (DDE). The universal testing machine and thermogravimetric analyzer) were used to measure the mechanical properties and thermal stability of the cured epoxy samples. The samples’ chemical resistance was assessed by calculating the weight loss in percent after they were submerged in solutions of NaOH, HCl, and NaCl. We also used scanning electron microscopy (SEM) to examine the morphological changes. Rosin-based epoxy cured with imidoamine curing agents outperformed the commercial epoxy in terms of performance.

Fabrication of tetraglycidyl epoxy nano-composites functionalized with amine-terminated zinc oxide with improved mechanical and thermal properties

The aim of the present work focuses on a newly developed ether-linked N, N-tetraglycidyl diamino-diphenyl ether (TGDDE) epoxy resin incorporated with the amine functionalized zinc oxide for the enhancement of the mechanical and thermal properties. TGDDE was synthesized using the starting material of 4,4-diamino-diphenyl ether (DDE) with epichlorohydrin (EPC). The synthesized TGDDE epoxy resin was characterized using FT-IR, 1H NMR and 13C NMR spectral analyses. The amine-functionalized zinc oxide (F–ZnO) was synthesized via the condensation method using 3-aminopropyl-triethoxysilane (APTES) and its preliminary structure was confirmed by FT-IR. The various weight percentages of F–ZnO (0.5, 1, and 2 wt%) were reinforced with TGDDE epoxy resin and cured with 4,4′-diaminodiphenylmethane (DDM). The mechanical and thermal behavior of the TGDDE epoxy matrix and nano-composites were analyzed by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). Consequently, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) were used for the prediction of the structural and surface morphology of the synthesized epoxy nanocomposites. The mechanical and thermal properties of the synthesized epoxy nanocomposites were enhanced to a greater extent by the inclusion of F–ZnO. The highest values were achieved in the mechanical properties, thermal stability and DMA analysis at 1 wt% addition of F–ZnO nanoparticles. The result of the study clearly shows that 1 wt% of F-ZnO with TGDDE epoxy resin can be used in various high-performance applications.

A strategy to construct low temperature curable copolyimides with pyrimidine based diamine

Low temperature curable polyimide (PI) films with outstanding mechanical and thermal properties are highly demanded in advanced packaging. Herein, a flexible diamine with pyrimidine named PMNH2 was synthesized and copolymerized with pyromellitic dianhydride (PMDA) and 4,4′-diaminodiphenyl ether (ODA), which showed significant influences on degree of imidization as well as the mechanical, thermal and dielectric properties of PI films. The copolyimide films have been proven almost complete imidization at 200 °C without any other curing accelerators. Meanwhile, the utilization of PMNH2 improved mechanical properties of copolyimide films greatly without severely sacrificing their thermal stability when curing at 200 °C. Copolyimide films containing 20 wt% and 30 wt% PMNH2 exhibited fairly high tensile modulus of 3.06 and 3.13 GPa, tensile strengths of 120 and 118 MPa, elongations at break of 61.1% and 20.1% and glass transition temperature of 352 and 342 °C, respectively. Moreover, the curable mechanism has been deeply probed by comparing the basicity and electron effects of the different diamine monomers via theoretical calculation, which showed an enlightening result that stronger basicity of pyrimidine-based diamine promoted the low temperature curing process, however the weaker electron-donating ability decreased the reactivity. Hence, both basicity and electron effects are key factors to be considered in designing new diamine monomer for low temperature curable PI films, providing opportunities of application in the advanced microelectronic package.

Hydroxyl-functionalized block co-polyimide enables simultaneously improved toughness and strength of tetrafunctional epoxy resin

Tetrafunctional epoxy resins are widely used as matrix of advanced composite materials due to their excellent high temperature performance. However, the highly crosslinking density of tetrafunctional epoxy resins results in an inherent brittleness, which limits its further application. In this work, hydroxyl-functionalized block co-polyimide (BPADA-ODA/HAB) is first synthesized by the condensation of 3,3′-Dihydroxybenzidine and 4,4′-Diaminodiphenyl ether with 4,4'-(4,4′-isopropylidenediphenoxy) di-phthalic anhydride, and used to toughen tetrafunctional epoxy resins. The co-polyimide molecules provide reactive blocks that participate in the curing reaction of epoxy resin and decrease the crosslinking density of epoxy resin; the co-polyimide can form nano-sized separated phase via self-assembly, which could activate additional energy dissipative mechanisms to enhance the resistance of failure for the epoxy resins. With 5% BPADA-ODA/HAB, the resultant epoxy resins exhibit simultaneous enhancements in impact strength and tensile strength, 184% and 150% higher than those of neat epoxy resin. This study provides an efficient method for preparing tough and strong tetrafunctional epoxy resins, which are expected to be applied more broadly in industries.

Hyperbranched polysiloxane (HBPSi)‐based colorless copolyimide films with atomic oxygen (AO) erosion resistance

AbstractColorless polyimides (CPIs) with excellent optical transparency and atomic oxygen (AO) erosion resistance have potential applications in optoelectronic devices in low earth orbit (LEO) such as flexible thin film solar cells. Herein, 2‐trifluoromethyl‐4,4′‐diaminodiphenyl ether (3F‐ODA) and amine‐terminated HBPSi were synthesized as amino monomers. After co‐polymerizing with 1,2,4,5‐cyclohexanetetracarboxylic dianhydride (CHDA) and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) in a typical sequential reaction manner, a series of CPI films with various HBPSi contents were fabricated. The resulting CPIs show high optical transmittance (84.8%–86.8% at 400 nm), outstanding atomic oxygen (AO) erosion resistance (AO erosion rate 4% that of pure CPI), satisfactory mechanical properties (tensile strength ca. 80 MPa, tensile modulus ca. 2.8 GPa), good thermal stability (Td ≥ 467 °C, Tg ≥ 304 °C) and desirable solubility. More importantly, the resulting CPIs show increasing AO resistance with the increase of HBPSi amount, and a fairly high optical transmittance can still be retained after AO exposure, far better than that of pure CPI. These impressive performances enable HBPSi CPIs capable of being used as substrate for lightweight solar cell arrays onboard spacecraft in LEO environment.

Molecular simulation of the O2 diffusion and thermo-oxidative degradation mechanism of carbon-doped boron nitride nanosheets/BTDA-ODA polyimide composites with high O2 adsorption capacity

Relevant studies have indicated that doping boron nitride nanosheets (BNNSs) into polyimide (PI) can significantly improve the thermal conductivity of composites and that the filling of inorganic nontechnical materials can inhibit the thermo-oxidative degradation of insulating polymer materials. Based on this information, three carbon-doped BNNSs models were obtained by modifying BNNSs. PI formed by the condensation of benzophenone-3,3 ',4,4 '-tetracarboxylic acid dianhydride (BTDA) and 4,4 '-diamino diphenyl ether (ODA) was used as a matrix to construct different composite models. Based on molecular simulation methods such as density functional theory (DFT) and reactive force field (ReaxFF), the diffusion of O2 through different composite systems and the inhibition of thermo-oxidative degradation of PI by different dopants were studied. The results showed that compared with pure BNNSs, the BNCB obtained by substituting carbon atoms for boron atoms on BNNSs better inhibited the thermo-oxidative degradation of PI. The adsorption of O2 and the inhibition of the O2 reaction at 2000 K with BNCB were significant improved compared with those with pure BNNSs. The content of the main products of PI thermo-oxidative degradation in the BNCB doping system was only 16% of that in the BNNSs system and the O2 consumption of the BNCB system was 34% lower than that of pure PI. By inhibiting the diffusion of O2 in PI, C-doped BNNSs reduced the contact between O2 and the PI matrix at high temperature, thus inhibiting the damage of O2 to the imide group and benzene ring in PI chains to improve the thermo-oxidative stability of composites. In this paper, a new C-doped BNNSs/PI model was designed based on the BNNS/PI composite model with high thermal conductivity, which achieved the double improvement of PI thermal conductivity and thermo-oxidative stability.

Preparation and gas separation performance of polyimide membranes endcapped with ionic liquid-type structures

A set of ionic liquid capped polyimide membranes was prepared using 1-aminoethyl-3-methylimidazolium hexafluorophosphate (IL1) and 1-aminopropylimidazolium bis(trifluoromethylsulfonyl)imine (IL2) as the terminal groups. The products’ molecular weights, mechanical properties, and separation permeability (CO2/CH4) were investigated. For CO2/CH4 separation, the selectivity of the ionic liquid capped polyimide membranes was higher than that of noncapped ones. Among them, the membrane synthesized by 4.4′- diaminodiphenyl ether and 4.4′-(hexafluoroisopropyl) diphthalic anhydride (6FDA) as monomer, with IL1 as terminal group, displayed the best selectivity. Its permeability was 7.47 Barrer and selectivity 102.42, which exceeded the 1991 Robeson curve. Polyimide membranes capped by ionic liquid showed high gas selectivity and good gas permeability as well as good physical and chemical properties. Consequently, it can be concluded that introducing an ionic liquid structure to polyimide chains could make attractive membrane materials for various gas separation and related applications.

Synthesis and Properties Comparison of Low Dielectric Silicon Containing Polyimides.

Recent studies have shown that the introduction of silicon can effectively improve the dielectric properties of polyimide (PI), and the introduction of a silicon–oxygen bond can increase the flexibility of the PI molecular structure, which is conducive to reducing the moisture absorption rate of PI materials. In this experiment, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyl disiloxane (DSX) was mixed with 4,4′-diaminodiphenyl ether (ODA) in different proportions. A series of PI films containing silicon was obtained by random polymerization with pyromellitic dianhydride (PMDA), 3,3′,4,4′-diphenylketotetrahedral anhydride (BTDA) and biphenyl dianhydride (BPDA), and then tetrad copolymerization with three kinds of dianhydrides. At the same time, the PI structures were put into calculation software to obtain the simulated polarization results, and then the films were characterized by various properties. The results showed that the characterization results were consistent with that of simulation, and the best overall PI formula was when the ratio of diamines was 1:9 and mixed with PMDA. The performance data were as follows: the vitrification temperature was about 320 °C, T5 was 551 °C, water absorption was 1.56%, dielectric constant (Dk) was 2.35, dielectric loss (Df) was 0.007, tensile strength was 70 MPa and elongation at break was 10.2%.

Study on the tribological properties of Si3N4/polyamide-imide composites

Si3N4 whiskers were modified with triethoxysilane as a means to improve the interfacial interaction with a poly-amide imide (PAI). The Si3N4/PAI composites were prepared by in-situ polymerization as an approach to improve the friction behavior and mechanical properties in order to meet the performance needs of electrical transformers and motors in harsh environments. 4,4′-diamino diphenyl ether, m-phenylenediamine, triethylamine, trimellitic anhydride chloride, and Si3N4 whiskers were used to manufacture Si3N4/PAI composite, which was then characterized for friction and mechanical behavior. The research showed that the addition of Si3N4 whiskers improved the mechanical properties and friction properties of PAI. When the whisker content was 10 wt%, the tensile strength of the composite was 137.5 MPa, which is 15% higher than pure PAI, and the wear rate was 0.69 × 10-8 g/N·m, which is 57% lower than pure PAI, and the friction coefficient was 0.47, which was an increase of 9%. In aerospace, machinery, and transportation applications, these materials may have better performance due to their improved combination of properties.

Integrated electronic skin (e-skin) for harvesting of TENG energy through push\u2013pull ionic electrets and ion-ion hopping mechanism

The development of highly durable, stretchable, and steady triboelectric nanogenerators (TENGs) is highly desirable to satisfy the tight requirement of energy demand. Here, we presented a novel integrated polymeric membrane that is designed by PEDOT: PSSa-naphthalene sulfonated polyimide (PPNSP)-EMI.BF4 Electronic skin (e-skin) for potential TENG applications. The proposed TENG e-skin is fabricated by an interconnected architecture with push–pull ionic electrets that can threshold the transfer of charges through an ion-hopping mechanism for the generation of a higher output voltage (Voc) and currents (Jsc) against an electronegative PTFE film. PPNSP was synthesized from the condensation of naphthalene-tetracarboxylic dianhydride, 2,2′-benzidine sulfonic acid, and 4,4′diaminodiphenyl ether through an addition copolymerization protocol, and PEDOT: PSSa was subsequently deposited using the dip-coating method. Porous networked PPNSP e-skin with continuous ion transport nano-channels is synthesized by introducing simple and strong molecular push–pull interactions via intrinsic ions. In addition, EMI.BF4 ionic liquid (IL) is doped inside the PPNSP skin to interexchange ions to enhance the potential window for higher output Voc and Iscs. In this article, we investigated the push–pull dynamic interactions between PPNSP-EMI.BF4 e-skin and PTFE and tolerable output performance. The novel PPNSP- EMI.BF4 e-skin TENG produced upto 49.1 V and 1.03 µA at 1 Hz, 74 V and 1.45 µA at 2 Hz, 122.3 V and 2.21 µA at 3 Hz and 171 V and 3.6 µA at 4 Hz, and 195 V and 4.43 µA at 5 Hz, respectively. The proposed novel TENG device was shown to be highly flexible, highly durable, commercially viable, and a prospective candidate to produce higher electrical charge outputs at various applied frequencies.