Search

The bioderived polycarbonate (ISB-PC) was synthesized via transesterification and polycondensation of isosorbide (ISB) and diphenyl carbonate (DPC), using lithium acetoacetone as catalyst. The resulting ISB-PC exhibited high glass transition temperatures similaring to bisphenol A polycarbonate (BPA-PC), and were thermally stable up to 350 ℃. The incorporation of isosorbitol into the polymer chain imparted an improved mechanical property of ISB-PC, such as a higher bending and tensile modulus and higher elongation at break. The ISB-PC can be readily cast into transparent films with a tensile strength of 73.3 MPa and a tensile modulu of 534 MPa. The ISB-PC displayed a highly UV transmittance and possessed a blue uorescence under the UV irradiation. At the same time, ISB-PC also has strong anti-yellowing ability.

In this work, ferroferric oxide (Fe3O4) microspheres with a diameter of ~ 150 nm were in situ grown on the surface of graphene oxide (GO) to obtain GO@Fe3O4 hybrids. Then, novel PMIA/CF/GO@Fe3O4 electromagnetic shielding composites have been developed with a simple and efficient paper-making method using poly(m-phenylene isophthalamide) (PMIA) fibers as matrix and carbon fiber (CF) and GO@Fe3O4 as fillers. Due to the introduction of GO@Fe3O4 and a large number of voids into the materials, the obtained PMIA/CF/GO@Fe3O4 composites exhibit good magnetic sensitivity and low density. Besides, the obtained PMIA/CF/GO@Fe3O4 composites with 10 wt% GO@Fe3O4 loading shows outstanding EMI-shielding effectiveness (EMI SE) of 42.55–46.98 dB at 8–12 GHz, and as the content of GO@Fe3O4 increases to 30 wt%, the EMI SE increases to 55.22 to 60.23 dB. The EMI SE of the PMIA/CF/GO@Fe3O4 composites is far more than the target value (20 dB) required by practical application. Thus, it provides a path to obtain a new class of high-performance and lightweight PMIA-based composites for enhanced shielding of electromagnetic pollution.

In this work, a series of fluorene-containing fluorinated polyethersulfone (PES-6AF/BHPF) copolymers with high temperature resistance and intrinsic low dielectric constant (low-e) have been designed and synthesized from 4,4′-dichlorophenyl sulfone (DCS) and polyphenol. The performance of obtained PES-6AF/BHPF can be controlled and optimized by controlling the copolymers structure. The thermal and dielectric properties of PES-6AF/BHPF were evaluated comprehensively. The obtained PES-6AF/BHPF copolymers show high glass transition temperatures (Tg) ranging from 200 to 260 °C, and 5% weight loss temperatures (Td5%) is stable up to 500 °C. The e value of PES-6AF/BHPF-0% and PES-6AF/BHPF-100% are as low as 2.1 and 2.3, and the loss tangent (tan δ) are only 0.0088 and 0.003 at 1 kHz, respectively. In addition, all of PES-6AF/BHPF films show good stability of dielectric properties in high temperature conditions. More importantly, the PES-6AF/BHPF copolymers are soluble in common solvents (such as DMAc, NMP, DMF, THF). The PES-6AF/BHPF copolymers are amorphous and can be easily cast into transparent and flexible films with tensile strength of 62–74 MPa and an elongation at break of 13.3–15.8%. The outstanding comprehensive properties made it possible to be the most promising polymer candidates for high-performance interlayer dielectrics.

In this work, ultralow dielectric constant (ultralow-k) polysulfone (PSF) composites were prepared by adding hollow glass beads (HGB) modified with 1,3-divinyltetramethyldisiloxane (DVTM). The results indicated that the surface modification of HGB (m-HGB) effectively enhanced the interfacial compatibility between the inorganic fillers and PSF matrix. DSC and TGA measurements of the composite films were performed under a nitrogen atmosphere, and the results showed that the composite films possess high glass transition temperatures varying from 187 °C to 190 °C, and are thermally stable␣up to 445 °C. The mechanical properties of composite films with modified HGB fillers show a certain drop, but the values were still higher than 32 MPa. Furthermore, the obtained composite films show low dielectric constant, low dielectric loss, good permittivity-frequency stability and dielectric-temperature stability under 190 °C. Therefore, we shown an effective path to prepare composites with ultralow dielectric constant for use in high temperature resistant ultra large scale integration (ULSI) flexible insulation substrate field.

A series of novel cross-linkable PSF-6AF/DBA copolymers with different structure were successfully synthesized via nucleophilic aromatic substitution stepwise polymerization of 4,4′-dichlorodiphenyl sulfone (DCS) with hexafluorobisphenol A (6AF) and 4,4′-(propane-2,2-diyl)bis(2-allylphenol) (DBA) monomer. The 6AF and DBA moieties with a large number of pendant groups had been successfully introduced into the PSF polymer chain. Then, the PSF-6AF/DBA films were fabricated by casting the PSF-6AF/DBA/DMF solutions with the concentration of 10% on the clean glass plates, followed by heat-treating all the films at 300 °C for 4 h. The effects of both the component and cross-linking on the thermal, mechanical and dielectric properties of the obtained films were investigated in detail. Compared to PSF-6AF/DBA films, the cross-linked PSF-6AF/DBA (CS-PSF-6AF/DBA) films show high glass transition temperature (Tg= 184–197 °C) and outstanding mechanical strength (64–77 MPa). More importantly, all CS-PSF-6AF/DBA films display stable dielectric properties in the temperature range of 20–200 °C. The permittivity of CS-PSE-6AF/DBA film at 1 kHz is as low as 2.1, while the dielectric loss is only 0.007.

In this work, the encapsulated barium titanate (BT) (C-PEN@BT) nanoparticles were successfully prepared via rotary coating technology combined with a post-treatment chemical bonding process, by using carboxyl-functionalized poly(arylene ether nitrile) (C-PEN) as modification agent. The TEM, FTIR and TGA results confirmed that the polymer layer (about 8 nm) has been uniformly surrounded on the surface of BT nanoparticles. Then, a facilitated physical dispersion technology was employed to prepare C-PEN@BT filled composite films using crystalline PEN as matrix and 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPH) as a novel cross-linking agent. The effects of both the surface modification of BT nanoparticles and matrix cross-linking on the mechanical, thermal and dielectric properties of PEN-based composites were investigated in detail. Compared with PEN-I film, the latter results showed that the strong interface interactions exerted between polymer matrix and CPEN layer on BT surface, especially the formation of cross-linking network across the PEN matrix, resulted in increased tensile strength and Young’ modulus by 29% and 32%, respectively. More importantly, the PEN/C-PEN@BT composite film shows stable dielectric properties in the temperature range of 20–204 °C, which is very close to the glass transition temperature.

Polyarylene ether nitrile (PEN) random copolymers were prepared from 6AF, BHPF, and 2, 6-dichlorobenzonitrile according to the nucleophilic aromatic substitution polymerization. The chemical structure of PEN random copolymers was characterized by the FT-IR and 1H-NMR spectrum, respectively. The thermal properties of the PEN random copolymers were investigated by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The resulting PEN copolymers have excellent thermal stability with high glass transition temperature (Tg) ranging from 187℃ to 271℃ and the 5% weight loss temperature (T5%) of PEN copolymers greater than 490℃ in nitrogen atmospheres. Meanwhile, the PEN films have excellent mechanical property, the tensile strength ranges from 55 to 95 MPa. Moreover, the dielectric properties of the PEN random copolymers were investigated by dielectric tests. The dielectric constants (k) and loss tangent (tan δ) of PEN (PEN-6-AF/BHPF100) film is only 2.3 and 0.03 at 1 kHz, respectively. More importantly, the dielectric properties were found to be relatively stable until the Tg, which can be attributed to the existence of BHPF units in the molecular backbone.

In this study, a series of fluorinated polyethersulfone (PES-6AF) copolymers with intrinsic low-dielectric-constants are prepared by the introduction of fluorine-containing group, which are derived from the polycondensation reaction of 4,4′-dichlorophenyl sulfone (DCS), bisphenol S (BPS) and six fluorine hexafluorobisphenolA (6AF) compounds by nucleophilic aromatic substitution. Different proportions of PES-6AF copolymers show high glass transition temperatures (Tg) ranging from 206 °C to 230 °C, and the thermal decomposition temperatures of PES-6AF copolymers are up to 500 °C under N2 atmospheres. The PES-6AF copolymers display outstanding tensile strength (62–69 MPa). Added different proportions of 6AF into the PES-6AF copolymers could improve dielectric property and decrease dielectric constant (k) from 3.6 to 2.5 at 1 kHz. In addition, the dielectric properties were found to be relatively stable until the Tg, it is because that the 6AF units were existed in the molecular backbone. Furthermore, the PES-6AF copolymers were soluble in many common solvents and could be made the molten films using DMF as solvent.

The waterborne polyurethane (WPU) with different carboxylic acid group contents were prepared by a prepolymer method, adopting polycarbonate diol (PCDL) as soft segments and isophorone diisocyanate (IPDI) as hard segments. The different amounts of 2,2-dimethylolbutyric acid (DMPA) as hydrophilic chain extender were introduced into polyurethane molecular for studying the effect on microstructure and properties. The solid content, pH value and viscosity measurement were used to characterize the performance of WPU emulsion. The fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), water contact angle tester and mechanical testing machine were utilized to measure the structure, crystallization performance, thermal stability, low temperature flexibility, wetting performance and mechanical properties of WPU films, respectively. The test value of impact, adhesive, flexibility and pencil hardness on tinplate of WPU coatings were obtained for observing film properties. The results indicated that the emulsification effect increase with the increased DMPA contents. The decomposition temperature of WPU films perform a slight decrease and the WPU films have excellence low temperature flexibility with the increased DMPA contents. The hydrophilic property of WPU films mainly are about 80°and the tensile strength value of 7 wt% WPU reaches 45 MPa and elongation at break at 420%.

Composite materials applied to capacitors with high dielectric constant, low dielectric loss and outstanding thermal stability are concerned widely in the field of dielectrics. So committed to the development of dielectric materials with excellent performance is the key factor. In this work, the barium titanate/polyether sulfone (BaTiO3/PES) composite films were prepared by a physical dispersion technology, which utilized a ball milling machine by high-speed circulation, scattered the PES solution contained BaTiO3 in deionized water with the aid of a surfactant. Then, the BaTiO3/PES composite films were obtained through a series of operations, containing reclaimed organic solvent, washed with deionized water, filtered, dried and hot pressed. The morphology of the BaTiO3/PES emulsion was investigated by TEM and SEM. The results showed that the BaTiO3 particles were covered in the PES resin matrix homogeneously. For 50 wt% BaTiO3 reinforced PES composite film. The dielectric constant increased by ~ 227% compared with pure PES resin (4.1 at 1 kHz) and the dielectric loss maintained around 10−2 magnitude, which performed better dielectric properties. The tensile strength of 10 wt% BaTiO3/PES composite films (72 MPa) reached the highest value in comparison with those of pure PES (58 MPa) due to the strengthened interaction between particles and matrix. Further increase of BaTiO3 content, the tensile strength and elongation at break decreased slightly but remained an excellent flexibility from the PES matrix. The temperature at weight loss 5% (T5%) of composite film with 40 wt% of BaTiO3 content reached up to 503 °C in N2 atmosphere. All the BaTiO3/PES composite films performed the concentrated glass transition temperature (Tg) around 229 °C. In sum, excellent thermal stability and dielectric properties would make the BaTiO3/PES composite films become the fine potential candidates for dielectric composites in the capacitors.

To develop high performance of polymer-based composites, the dispersion state and interfacial interaction of nano-fillers are two key issues to be considered. Herein, we report the surface decoration of basalt fibers (BF) with nano-sized barium titanate (BT) particles and their dielectric application in poly(ether sulfone)-based composite laminates (PBCLs) was investigated in detail. Firstly, the nano-sized BT particles uniformly deposited along the BF surface through a simple and effective solvothermal method, as confirmed by SEM and XRD measurement. Then, novel ternary dielectric polymer-based composite laminates, consisting of BT particles decorated BF and poly(ether sulfone) (BT–BF/PES), were fabricated by hot-pressing method. Compared to raw BF filled PBCLs, the SEM images of BT–BF fibers reinforced PBCLs showed that all the BT–BF fibers strongly adhere to the PES matrix, and obscure fiber/PES interfaces are present without visible boundaries, indicating a improved interfacial interactions in this case. Thus, the mechanical, thermal and dielectric properties of the resultant PBCLs were characterized and results indicated that the BF and BT particles show enhanced synergistic effects. Following this strategy, the flexural strength and dielectric constant of BT–BF/PES blend with 40 wt% of BT were increased by 28 and 350%, respectively, in comparison with those of BF/PES composite laminates.

Core–shell structured magnetic carbon nanotubes (CNTs-Fe3O4) coated with hyperbranched copper phthalocyanine (HBCuPc) (HBCuPc@CNTs-Fe3O4) hybrids were prepared by the solvent-thermal method. The results indicated that the HBCuPc molecules were decorated on the surface of CNTs-Fe3O4 through coordination behavior of phthalocyanines, and the CNTs-Fe3O4 core was completely coaxial wrapped by a functional intermediate HBCuPc shell. Then, polymer-based composites with a relatively high dielectric constant and low dielectric loss were fabricated by using core–shell structured HBCuPc@CNTs-Fe3O4 hybrids as fillers and polyarylene ether nitriles (PEN) as the polymer matrix. The cross-sectional scanning electron microscopy (SEM) images of composites showed that there is almost no agglomeration and internal delamination. In addition, the rheological analysis reveals that the core–shell structured HBCuPc@CNTs-Fe3O4 hybrids present better dispersion and stronger interface adhesion with the PEN matrix than CNTs-Fe3O4, thus resulting in significant improvement of the mechanical, thermal and dielectric properties of polymer-based composites.

A novel soluble poly(aryl ether ketone) (PAEK) terminated with 4-nitrophthalonitrile was designed and synthesized, which was used to solve the problem of difficult solution processing. Then, a series of cross-linked PAEK films with different thermal treatment temperatures were fabricated by using 4,4-bis(3,4-dicyanophenoxy)biphenyl (BPH) as a novel cross-linking agent, improving the glass transition temperature (Tg) of the traditional PAEK. Then, the fourier transform infrared (FT-IR) spectrum, X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), dynamic mechanical analysis (DMA), mechanical testing machine and LCR meter were used to investigate the microstructure, thermal, mechanical and dielectric properties of PAEK films, respectively. The results indicated that the increase in heat-treatment time and temperature are beneficial for the improvement of the value of Tg and T5%, and the excellent thermal stability and mechanical properties of PAEK films are demonstrated. Compared to PAEK-1 film, the Tg and T5% both increased by 63 °C for PAEK-4 film. Significantly, the tensile strength of PAEK-3 film (42 MPa) reaches the highest value in comparison with other samples. In addition, the dielectric constants (e) and loss tangent (tan δ) of PAEK-4 film is as low as 3.67 and 0.001 at 1 kHz, respectively. More importantly, the dielectric properties are found to be relatively stable to near the Tg value, which can be widely used for applications in dielectric energy storage at high temperatures.

In this study, novel green-emitting waterborne polyurethane (WPU) was synthesized through a blocking prepolymer method to study the effect on fluorescence properties, adopting fluorescein isothiocyanate (FITC) as green-emitting extender was blocked into polyurethane main chain. The chemical structure of fluorescent WPU film was characterized by FTIR and SEM. The effects of the FITC on the fluorescent properties of FWPU were investigated in detail by UV–Vis absorption spectroscopy and molecular fluorescence spectroscopy (MFS), respectively. The results indicated that FWPU has higher fluorescence intensity than FITC and its fluorescence stability is outstanding.

Sandwich-like graphite–fullerene composites have been prepared via a simple solution mixing/evaporation method. The complex relative permittivity and permeability of the graphite–fullerene composites in the frequency range from 0.5 GHz to 18 GHz were measured using a vector network analyzer with the reflection/transmission technique. Additionally, the microwave reflection loss of the composites was calculated using the obtained complex microwave electromagnetic parameters. It was found that the microwave loss peaks in the Ku band were dependent on the concentration of fullerene nanoparticles in the composites. Maximum reflection loss of −30 dB was observed between 2 GHz and 8 GHz when the graphite composites were doped with 1 wt.% fullerene. This absorption loss dropped (−24 dB) when the composite contained 3 wt.% fullerene. In addition, the electrical properties of the graphite were independent of the presence of fullerene in the composites. The tunable microwave reflection loss indicates that these graphite–fullerene composites show promise as wideband electromagnetic wave absorption materials.

Novel graphene oxide@Fe 3 O 4 /iron phthalocyanine (GO@Fe 3 O 4 /FePc) hybrid materials were prepared through a facile one-step solvothermal method with graphene oxide (GO) sheets as template in ethylene glycol. The morphology and structure of the hybrid materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrophotometer (FTIR) and X-ray diffraction (XRD), respectively. The results indicated that the monodispersed Fe 3 O 4 /FePc hybrid microspheres were uniformly self-assembled along the surface of GO sheets through electrostatic attraction and the morphology can be tuned by controlling the amount of 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPH). As the BPH content increases, magnetization measurement of the GO@Fe 3 O 4 /FePc hybrid materials showed that the coercivity increased, while saturation magnetizations decreased. Electromagnetic properties of the hybrid materials were measured in the range of 0.5–18.0 GHz. The microwave absorbing performance enhanced with the increase of BPH content and a maximum reflection loss of −27.92 dB was obtained at 10.8 GHz when the matching thickness was 2.5 mm. Therefore, the novel electromagnetic hybrid materials can be considered as potential materials in the microwave absorbing field.

Conductive Poly (3,4-ethylenedioxythiophene) (PEDOT) nanofibers are uniformly deposited on ultrathin graphene oxide (GO) nanosheets via a simple and effective in situ polymerization process under ambient conditions. The as-prepared samples are characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectra, Fourier transforms infrared spectra (FTIR), and electrochemical measurements. The results indicate that the as-obtained PEDOT&ndash, GO hybrid (GDOT) achieves excellent sodium storage properties. When explored as a new inorganic/polymeric electrode for sodium ion batteries (SIBs), the GDOT exhibits a high reversible capacity (338 mAh g&minus, 1), good cycling stability (234 mAh g&minus, 1 after 400 cycles), and excellent rate capabilities (e.g., 62 mAh g&minus, 1 at 30 A g&minus, 1) due to their ultrathin structure as well as conductive network. This easily scale-up-able and effective strategy shows great potential for large-scale energy applications.

In this work, a series of novel organosoluble copoly(arylene ether nitriles) containing thioether moiety (PENS) were synthesized via nucleophilic aromatic substitution polymerization of 2,6-dichlorobenzonitrile with bisphenol A and sodium sulfide nonahydrate, using N-Methyl-2-Pyrrolidone as solvent in the presence of anhydrous potassium carbonate. The chemical structures of PENS were characterized by FTIR and 1H NMR. The derived copolymers showed high glass transition temperatures in the range of 167–178 °C and excellent thermal stability with the 5% weight loss temperatures ranging from 465 °C to 503 °C. Meanwhile, all of the PENS were amorphous and can be readily cast into transparent films with a tensile strength exceeding 77 MPa and a breaking elongation over 4.8%.In addition, the dielectric constant of all the PENS copolymers showed weak frequency dependence, the dielectric loss showed slight decrease with increasing frequency over the range of 100 Hz to 200 kHz. Therefore, this kind of organosoluble copoly(arylene ether nitriles) containing thioether moiety could be a good candidate as matrix resins for high-performance polymeric materials.

Polyarylene ether nitrile (PEN) nanofibrous mat was fabricated by using the electrospinning technique and activated by using NaOH solution. The adsorption capacity of the activated PEN nanofibrous mat was evaluated using Cu2+ as the model hazardous metal ions. The effects of the contact time and the initial concentration of Cu2+ solution (C0) on the adsorption capacity of the mat were investigated. The adsorption kinetics was better described by the pseudo-second order equation, and the adsorption isotherm was better fitted for the Langmuir equation. Furthermore, the nanofibrous mat possesses the potential of regeneration and reuse. All of the results in this paper show that the PEN nanofibers produced via the electrospinning technique have excellent adsorbent properties toward Cu2+ ions.

Functionalization of carbon nanotubes (CNTs) is considered as an essential step to enable their manipulation and application in potential end-use products. In this paper, novel ternary dielectric polymer-based nanocomposite films, consisting of hyperbranched copper phthalocyanine grafted carbon nanotubes and polyarylene ether nitriles (PEN/HBCuPc-g-CNTs), were prepared via solution-casting method. The CNTs are enwrapped by a functional intermediate HBCuPc thick layer and formed rough shell on the surface of CNTs to ensure a good dispersion of CNTs in PEN matrix and suppress the mobility of free charge carriers effectively, resulting in significant improvement of the dielectric properties of PEN/HBCuPc-g-CNTs nanocomposite films in contrast to PEN/CNTs. Furthermore, around 38 wt% of phthalocyanine oligomer based on the total weight of the CNTs can be covalently grafted to the surface of the CNTs. Compared with raw CNTs, grafted CNTs showed better dispersion and stronger interfacial adhesion to PEN matrix. SEM images showed that HBCuPc-CNT was perfectly embedded in the matrix and no pullout phenomenon could be observed, thus resulting in significant improvement of the mechanical and thermal properties of PEN/HBCuPc-g-CNTs nanocomposite films compared to pure PEN films. For 2.0 wt% HBCuPc-g-CNTs reinforced PEN nanocomposite films, the tensile strength and T g were increased by 24.5 % and 5 °C, respectively, in comparison with those of pure PEN.

To develop high-performance inorganic particles/polymer composites, the interfacial interaction and dispersion of inorganic particles are the two essential issues to be considered. Herein, we report an effective approach to graft iron phthalocyanine containing flexible chains (NP-ph) on Fe 3 O 4 nanoparticles (NP-ph@Fe 3 O 4 ). The hybrids were monodispersed solid nanoparticles with the average diameter of about 250 nm. About 16.8% of the phthalocyanine oligomer was incorporated into the resulting NP-ph@Fe 3 O 4 nanoparticles. The NP-ph@Fe 3 O 4 nanoparticles were subsequently used as the novel filler for preparation of high performance poly(arylene ether nitrile)s (PAEN) composites. The scanning electron microscopy (SEM) investigation showed that the NP-ph@Fe 3 O 4 nanoparticles present better dispersion and interfacial compatibility with PAEN matrix than that of raw Fe 3 O 4 , which was further confirmed by rheological study. Consequently, the improved thermal stability and enhanced mechanical properties were obtained from composites using NP-ph@Fe 3 O 4 . Vibrating sample magnetometer (VSM) results showed that the prepared PAEN composites exhibited higher saturation magnetization and soft magnetic properties. Meanwhile, the saturation magnetization (Ms) of the PAEN/NP-ph@Fe 3 O 4 composite films increased with the increase of the hybrid nanoparticles loading. Thus, the PAEN/NP-ph@Fe 3 O 4 composite would find potential applications in organic magnetic films fields due to their high thermal stability, excellent flexibility and tunable magnetic properties .

Novel carboxylic poly(arylene ether nitrile)s (CPEN) functionalized carbon nanotubes (CPEN-f-CNTs) were successfully prepared by a simple and effective solvent–thermal route. The CPEN-f-CNTs were subsequently used as the novel filler for preparation of high performance poly(arylene ether nitrile)s (PEN) nanocomposites. The SEM characterization of the PEN nanocomposites revealed that the CPEN-f-CNTs present better dispersion and interfacial compatibility in the PEN matrix, which was confirmed by the linear rheological analysis (Cole–Cole plots) as well. Consequently, the improved thermal stability (increased initial and maximum decomposition temperature) and enhanced mechanical properties (tensile strength and modulus) were obtained from nanocomposites using CPEN-f-CNTs. More importantly, the PEN/CPEN-f-CNTs nanocomposites not only show a high dielectric constant but also have low dielectric loss. For example, a dielectric constant of 39.7 and a dielectric loss of 0.076 were observed in the PEN composite with 5 wt% CPEN-f-CNTs loading at 100 Hz. Therefore, the flexible PEN/CPEN-f-CNTs nanocomposites with outstanding mechanical, thermal and dielectric properties will find wide application in the high energy density capacitors. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

Cross-linkable poly(arylene ether nitrile)s containing side propenyl groups (DPEN) were synthesized through nucleophilic aromatic substitution polymerization from biphenol, 2,2′-diallylbisphenol A (DBA), and 2,6-dichlorobenzonitrile. The structures of resultant copolymers were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopies. The properties of copolymers were investigated by thermal (differential scanning calorimetry and thermogravimetric analysis) analysis, inherent viscosity measurements, and mechanical tests. The results showed that allyl groups rearranged into propenyl groups during the polymerization. The copolymers with increasing content of DBA had high glass transition temperatures ranging from 207°C to 169°C and good thermal and thermo-oxidative stability with the 5 wt% loss temperatures in the range of 511–423°C under nitrogen and 471–402°C in air atmospheres, respectively. They also exhibited good mechanical property with tensile strength of 105–79 MPa. Meanwhile, the cross-linking reaction was studied through heat treatment. The result showed that the properties of DPEN containing side propenyl groups changed obviously after heat treatment, due to the fact that the double bond of PEN can be readily cross-linked to form net-shape polymers at high temperature.

In this work, the biphenol polyarylether nitrile (BP-PEN) films with improved processability were prepared by blending low molecular weight (LMW) with high molecular weight (HMW) of BP-PEN. The hybrid membrane exhibited excellent thermal stability and mechanical strength. The Tid values of the films were as high as 505°C–522°C. Melting behavior studies indicated that the crystallinity of LMW BP-PEN was higher than that of HMW, which was confirmed by the X-ray diffraction (XRD) patterns analysis as well. Scanning electron microscope (SEM) provided additional information on morphology and phase adhesion. Additionally, the polymer crystallinity dependent on dielectric properties of blends films is reported. Most importantly, it is found that the combination of LMW and HMW BP-PEN would be an effective method to simultaneously increase the mechanical, thermal, dielectric properties, and polymer processability. POLYM. COMPOS., 2015. © 2015 Society of Plastics Engineers

The surfaces of graphene oxide (GO) sheets were coated with fiber-like copper phthalocyanine (CuPc) by use of a solvothermal process. The product, GO@ CuPc, was used as a filler in high-performance poly(arylene ether nitrile) (PEN) composites. Films of the composites had high thermal stability, and glass-transition temperatures in the range 170–182°C. Thermogravimetric analysis revealed their initial decomposition temperatures were in the range 470–483°C. Scanning electron microscopy showed that dispersion of GO@ CuPc in PEN was much better than that of unmodified GO; this can be attributed to relatively strong interaction between GO@CuPc and the PEN matrix. All the composite films were highly flexible and had enhanced mechanical properties. Tensile strengths of the composites were as high as 89 MPa in the presence of 1 wt.% GO@CuPc, an increase of 20% compared with pure PEN film. Dielectric constants of the composite films were as high as 52 at 100 Hz when the GO@CuPc content was 5%. Because of these excellent mechanical and dielectric properties, PEN/GO@CuPc composites have much potential for use as film capacitors.

The addition of a small amount of sulfonated multi-walled carbon nanotubes (3 wt%) to a sulfonated polyarylene ether nitriles (SPEN) proton exchange membrane using an acyl chloride method was proved to be an effective way to improve the mechanical behaviour and proton conductivity performance.

Novel hyperbranched copper phthalocyanine covalently grafted carbon nanotube/polyarylene ether nitrile (HBCuPc-CNT/PAEN) flexile composite films were prepared via solution casting. The CNTs are enwrapped by a functional intermediate HBCuPc thin layer which forms a rough shell on the surface of the CNTs to ensure a good dispersion of CNTs in the PAEN matrix. The dielectric layer (HBCuPc-CNTs) is intercalated by insulating layers (pure PAEN, acting as the isolating layer). Due to the high capacitance of the dielectric layer and the effective blocking of the mobility of free charge carriers by the insulating layers, the polymer-based composite films exhibit not only a high permittivity but also an extremely low dielectric loss and excellent breakdown strength. SEM images show that HBCuPc-CNTs are perfectly embedded in the matrix and no pull-out phenomenon can be observed. In addition, the rheological properties of the resulting composite films also indicate that the grafted CNTs present a good dispersion and strong interactions with the PAEN resin, thus resulting in a significant improvement of the mechanical and thermal properties of the PAEN composite films.

In this report, flexible cross-linked polyarylene ether nitrile/functionalized barium titanate(CPEN/F-BaTiO3) dielectrics films with high permittivitywere prepared and characterized. The effects of both the F-BaTiO3 and matrix curing on the mechanical, thermal and dielectric properties of the CPEN/F-BaTiO3 dielectric films were investigated in detail. Compared to pristine BaTiO3, the surface modified BaTiO3 particles effectively improved their dispersibility and interfacial adhesion in the polymer matrix. Moreover, the introduction of F-BaTiO3 particles enhanced dielectric properties of the composites, with a relatively high permittivity of 15.2 and a quite low loss tangent of 0.022 (1 kHz) when particle contents of 40 wt % were utilized. In addition, the cyano (–CN) groups of functional layer also can serve as potential sites for cross-linking with polyarylene ether nitrile terminated phthalonitrile (PEN-Ph) matrix and make it transform from thermoplastic to thermosetting. Comparing with the pure PEN-ph film, the latter results indicated that the formation of cross-linked network in the polymer-based system resulted in increased tensile strength by ~67%, improved glass transition temperature (Tg) by ~190 °C. More importantly, the CPEN/F-BaTiO3 composite films filled with 30 wt % F-BaTiO3 particles showed greater energy density by nearly 190% when compared to pure CPEN film. These findings enable broader applications of PEN-based composites in high-performance electronics and energy storage devices materials used at high temperature.

In this work, copper phthalocyanine (CuPc) polymers of excellent electrical conductivity were successfully prepared via a high temperature sintering procedure, the chemical structures and morphology of obtained CuPc polymers were characterized by FTIR and SEM, respectively. Thereafter, CuPc/polyarylene nitrile ethers (PEN) composite films were prepared via solution-casting method. The obtained films show excellent thermal, mechanical and dielectric properties due to the good dispersion and compatibility of conductive CuPc polymers in PEN matrix, which was confirmed by the SEM characterization.

Novel dandelion-like titanium oxide (TiO2) decorated reduced graphene oxide (rGO@TiO2) hybrids were obtained by a one-step solvent-thermal reduction of GO and tetrabutyl titanate simultaneously. The hybrids were used as a novel filler for high performance poly(arylene ether nitriles) (PEN) composites. The thermal stability and morphological properties of the PEN composites were, respectively, investigated by the thermo gravimetric analysis and scanning electron microscope, aiming at examining the effect of surface decoration on the dispersion of rGO@TiO2 in PEN matrix. The results indicated that the rGO@TiO2 present better dispersion in the PEN matrix. Meanwhile, the derived composite films exhibited high thermal stability with initial decomposition temperatures (T id ) in the range of 477–487 °C. DSC curves showed that the glass transition temperatures were in the range of 219–227 °C. Moreover, all of the composite films also showed excellent flexibility and mechanical properties. The tensile modulus and strength were increased about 4 and 6 % with 5 wt% rGO@TiO2 loading, respectively. More importantly, for 30 wt% rGO@TiO2 reinforced PEN composite film, the dielectric permittivity dramatically increased from 3.8 to 81 at 1 kHz.

In this work, polymer-based nanocomposite films formed from biphenol poly(arylene ether nitrile) (BP-PEN) and multiwalled carbon nanotubes (MWCNTs) were successfully prepared by the solution casting method combined with continuous ultrasonic dispersion technology. The micromorphology, thermal, mechanical and dielectric properties of the nanocomposite films were investigated in detail. Non-isothermal crystallization behavior studies indicate that the presence of MWCNTs enhances the crystallization of BP-PEN in the nanocomposites, which is consistent with the XRD analysis. Most importantly, it could be observed that the film containing 0.8 wt% MWCNTs reached the maximum crystallinity. Although, incorporation of MWCNTs did not obviously increase the mechanical of the films, all the nanocomposite films still exhibited excellent mechanical strength. The SEM micrographs of the nanocomposite films showed that the MWCNTs were uniformly coated by BP-PEN crystals, and indicating significantly improved nucleation ability of MWCNTs for polymer crystallization.

Polymer-based composite films were prepared by employing core/shell-structured tetranitrophthalocyanine copper/titanium dioxide (TNCuPc–TiO2) hybrid particles as fillers and poly(arylene ether nitrile)s (PEN) as polymer matrix. Core/shell-structured TNCuPc–TiO2 hybrid particles were successfully synthesized through a facile solvothermal synthesis route. Compared with raw TiO2, the dispersibility and interfacial compatibility between TNCuPc–TiO2 hybrid particles and PEN matrix were observably improved because the TNCuPc decorated on the TiO2 can interact with nitrile groups in PEN. Consequently, core/shell-structured TNCuPc–TiO2 had a more significant enhancement effect on the properties of PEN. Although the mechanical strength was reduced to 41 MPa, all of the composite films exhibited excellent thermal stability. Their initial decomposition temperatures were up to 510°C, and the glass-transition temperatures were over 191°C. More importantly, the permittivity of the composite film was as high as 19.8 at 100 Hz when the weight fraction of TNCuPc–TiO2 hybrid particle loading reached 40.0 wt.%. Compared with the permittivity of PEN/TiO2 composite films with 40.0 wt.% raw TiO2 particle loading, the dielectric constant was increased by 161%.

A novel series of PEN- t -Ph/Fe 3 O 4 hybrid submicron spheres with different additions of PEN- t -Ph have been prepared successfully via solvothermal method, and their structures and morphologies were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometer (EDS), Fourier transform infrared spectrophotometer (FTIR), and scanning electron microscopy (SEM). The results revealed that the crystallinity, dispersity, and size of hybrid submicron spheres can be controlled by altering the addition content of PEN- t -Ph. Magnetization measurement showed that the PEN- t -Ph/Fe 3 O 4 hybrid submicron spheres possessed good ferrimagnetism. The electromagnetic measurement indicated that the resonance peaks of complex permittivity, complex permeability, dielectric loss, and magnetic loss were shifted to the higher frequency as the addition of PEN- t -Ph increased. Moreover, the microwave absorption band was also shifted to higher frequency as the addition of PEN- t -Ph increased. Through this method, the polymer compatibility can be introduced into inorganic submicron spheres, which could provide the inorganic particles with more applications.

Polyarylene ether nitrile (PEN)/multi-walled carbon nanotubes (MWCNTs)/alumina (Al2O3) micro-nanocomposite material films were fabricated by uncomplicated and accessible method, overcoming the difficulty of bad interaction between MWCNTs and PEN matrix. Scanning electron microscope revealed that MWCNTs were isolated by Al2O3 and realized better dispersion in matrix. Al2O3 particles hindered conductive MWCNTs from bridging with each other, working as dielectric obstacle. In addition, the micro-nanocomposite has excellent thermal stability and possesses high performance in dielectric and mechanical. The investigation results showed that the dielectric constant increased to 100.8 (50 Hz), which is 20 times higher than that of pure PEN while the dielectric loss was only 0.1 with 7 wt% MWCNTs loading. Meanwhile, the mechanical property indicated that the composite with 7 wt% MWCNTs loading reached their highest values. In other words, the composite with 7 wt% MWCNTs loading possess excellent mechanical property simultaneously as it reached the percolation threshold.

In this paper, a series of novel BaTiO3@MWCNTs core/shell heterostructure have been successfully synthesized via the solvent-thermal method. By adjusting the molar ratio of BaTiO3 and MWCNTs, BaTiO3@MWCNTs heterostructure with different morphologies and electromagnetic absorb performances were obtained. Energy dispersive Spectrometer and X-ray diffraction analysis reveal that the product is composed of Ba, Ti, O and C elements and the crystal structure of BaTiO3 is cubic perovskite. Besides, SEM and TEM images show that MWCNTs cores are coated with BaTiO3 shells, which are self-assembled by BaTiO3 nanoparticles. Moreover, the absorption peaks shift from high frequency to low frequency as the calculated absorber layer thickness increases. Most importantly, the maximum peak value of BaTiO3@MWCNTs heterostructure (10:1) reaches −45.0 dB at 5.5 GHz when the thickness of absorber layer is 3.5 mm.

A novel multi-wall carbon nanotubes-copper phthalocyanine (MWCNTs-CuPc) hybrid material was successfully prepared from 1, 3, 5-tri-(3, 4-dicyanophenoxy) benzene (TPh) and CuCl through a simple and effective solvent-thermal route. FTIR, SEM and TEM results display that the convex surfaces of MWCNTs were successfully coaxially coated by self-assembly organic functional materials. This can effectively prevent MWCNTs from agglomeration, and also can greatly improve their dispersibility and compatibility in polyarylene ether nitriles (PEN) matrix through intermolecular interaction. Most importantly, the permittivity of the nanocomposite film is as high as 55 at 100 Hz when the mass fraction of CuPc-MWCNTs reaches 5.0 wt%.