Polymer Composite Films Research Articles

Enhancing the dielectric characteristics of argon beam irradiated polymer composite films

In this study, the casting prepration technique is applied to produce flexible CA/PANI composite films. The CA/PANI samples which are composed of polyaniline (PANI) and cellulose acetate (CA) are directed to applied in electrical storage devices. The XRD, FTIR, TEM, Ramman and SEM techniques were employed for analyzing the produced films. The TEM show the PANI were formed with the particle size less than 100 nm. Next, argon-ion beam with varying fluencies (4x1014, 8x1014 and 12x1014 ions/cm2) bombard the CA/PANI samples. In frequency of 20 Hz to 5.5 MHz, the dielectric properties of CA/PANI were significantly altered by argon beam treatment. The irradiated sample by 12x1014 ions/cm−2 at frequency 50 Hz resulted in an improvement in the dielectric constant ε′ from 36.4 for the unirradiated CA/PANI to 108.6. Additionally, the relaxation time decreased from 1.63x10−4 sec to 2.08x10−5 sec. The results of this work open the ways for using the irradiated CA/PANI in a number of devices, such as supercapacitors and batteries.

Tailoring the optical properties of dye–polymer composite films based on polyvinyl alcohol doped with phenol red toward flexible optoelectronic applications

The composite films of polyvinyl alcohol (PVA) incorporating varying concentrations of phenol red (PR) dye were fabricated using the solution casting method. Structural characteristics of the prepared films were explored through XRD and FTIR spectroscopy analyses. The inclusion of PR dye within the PVA matrix induced cross-linking, enhancing the amorphous nature of the doped PVA samples, as evidenced by XRD patterns. In the presence of PR dopants, the FTIR peaks for PVA exhibited altered intensities and increased width, indicating physical interactions between the functional groups of PVA and PR dopants. The impact of PR additives on the optical properties of PVA was investigated across the spectral range of 190–2500 nm. The PVA/phenol red composite demonstrated enhanced UV blocking in the 190–400 nm wavelength range, rendering it suitable for applications such as UV notch filters, including laser blocking filters. The indirect and direct optical band-gaps of PVA polymer films were reduced from 5.20 eV and 5.78 eV to 4.30 eV and 5.28 eV, respectively, with an increase in the PR filling ratio from 0 wt% to 1.8 wt%. The dispersion region of the refractive index was analyzed using the single oscillator model (Wemple-DiDomenico). Calculation and discussion of values such as dispersion and oscillation energies (Ed and Eo), permittivity at infinite frequency (ε ∞), and lattice contribution to the dielectric function (ε L) of PVA/PR composite films were conducted. These advancements position PVA/PR composite films for potential applications in flexible optoelectronic devices, including light-emitting diodes and photodetectors.

Voltage-assisted 3D printing of polymer composite dielectric films with low energy loss and high energy storage density

PVDF-based polymers have garnered significant attention in the field of high-power density electrostatic capacitors due to their exceptional dielectric strength. However, their practical applications are constrained by low charge-discharge efficiency (η) and energy storage density (Ue), which stem from high ferroelectric relaxation and low breakdown strength (Eb). Here, a hydrogenated glassy polymer poly(styrene-methyl methacrylate-methylallyl alcohol) (PSMA) is designed and synthesized to be homogeneously distributed in PVDF through voltage-assisted 3D printing-hot pressing, resulting in a flexible composite film. The findings demonstrate that PSMA, rich in hydrogen bonds and high modulus strength, effectively mitigates the ferroelectric phase transition of PVDF to enhance η. Additionally, the voltage-assisted 3D printing process induces an entropy gain mechanism, facilitating the uniform distribution of the two phases and enhancing the interfacial properties for enhancing Eb. Remarkably, the study achieves prominent growth in energy storage performance, with Ue and η reaching 18.1 J/cm3 and 80 % at 525 MV/m, respectively. These remarkable results highlight the potential of 3D printing technology in enhancing the energy storage performance of PVDF-based dielectrics.

Self-Assembled MXene@Fluorographene Hybrid for High Dielectric Constant and Low Loss Ferroelectric Polymer Composite Films.

Modern electrical applications urgently need flexible polymer films with a high dielectric constant (εr) and low loss. Recently, the MXene-filled percolative composite has emerged as a potential material choice because of the promised high εr. Nevertheless, the typically accompanied high dielectric loss hinders its applications. Herein, a facile and effective surface modification strategy of cladding Ti3C2Tx MXene (T = F or O; FMX) with fluorographene (FG) via self-assembly is proposed. The obtained FMX@FG hybrid yields high εr (up to 108 @1 kHz) and low loss (loss tangent tan δ = 1.16 @ 1 kHz) in a ferroelectric polymer composite at a low loading level (the equivalent of 1.5 wt % FMX), which is superior to its counterparts in our work (e.g., FMX: εr = 104, tan δ = 10.71) and other studies. It is found that the FG layer outside FMX plays a critical role in both the high dielectric constant and low loss from experimental characterizations and finite element simulations. For one thing, FG with a high F/C ratio would induce a favorable structure of high β-phase crystallinity, extensive microcapacitor networks, and abundant interfacial dipoles in polymer composites that account for the high εr. For another, FG, as a highly insulating layer, can inhibit the formation of conductive networks and inter-FMX electron tunneling, which is responsible for conduction loss. The results demonstrate the potential of a self-assembled FMX@FG hybrid for high εr and low loss polymer composite films and offer a new strategy for designing advanced polymer composite dielectrics.

Fabrication of PVA-based electromagnetic interference shielding composite film by improving the dispersibility of carbon nanomaterial via m-LDH modification

A good dispersion of carbon (C) nanoparticles is a crucial factor to ensure good electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) performance of polymer-based composite films. In the present work, water-dispersed monolayer layered double hydroxides (m-LDH) was used to modify the C nanoparticles via an in-situ growth method and applied as the conductive fillers for polyvinyl alcohol (PVA) composite films. The prepared C@m-LDH hybrids displayed good water dispersibility due to the in-situ growth of m-LDH with high dispersibility and small particle size on the surface of C nanoparticles, as well as the synergistic effect of styrene-maleic anhydride copolymer attached to the m-LDH surface. The property testing experiments for the PVA composite films demonstrated that compared with pristine C nanoparticles, as-prepared C@m-LDH hybrids exhibited greatly enhanced the electrical conductivity and higher EMI SE performance. Moreover, PVA/C@m-LDH composite film exhibit remarkably low permeation thresholds, especially PVA/CB@m-LDH composite film, CB@m-LDH content is only 0.4 wt%. In order to further improve the electrical conductivity and EMI SE performance, hybrid fillers of CB@m-LDH/CNT@m-LDH were added in the composite films with different mass ratios. Among, the polymer composite films containing 30 wt% CB@m-LDH/CNT@m-LDH with a mass ratio of 12:1 achieves a high EMI SE value up to 29 dB at a thickness of 0.2 mm, indicating the potential use of these materials for electromagnetic shielding application in the X-band frequency region. The present study paves the way for designing high-performance polymer-based composite film by Cnanoparticles functionalization and altering processing conditions for efficient microwave shielding material.

Transparent ultrahigh-molecular-weight polyethylene/MXene films with efficient UV-absorption for thermal management

The rational use and conversion of energy are the primary means for achieving the goal of carbon neutrality. MXenes can be used for photothermal conversion, but their opaque appearance limits wider applications. Herein, we successfully develop visible-light transparent and UV-absorbing polymer composite film by solution blending the MXene with polyethylene and then vacuum pressing. The resulting film could be quickly heated to 65 °C under 400 mW cm−2 light irradiation and maintained over 85% visible-light transmittance as well as low haze (<12%). The findings of the indoor heat insulation test demonstrate that the temperature of the glass house model covered by this film was 6-7 °C lower than that of the uncovered model, revealing the potential of transparent film in energy-saving applications. In order to mimic the energy-saving condition of the building in various climates, a typical building model with this film as the outer layer of the window was created using the EnergyPlus building energy consumption software. According to predictions, they could reduce yearly refrigeration energy used by 31-61 MJ m−2, and 3%-12% of the total energy used for refrigeration in such structures. This work imply that the film has wide potential for use as transparent devices in energy-related applications.

Characterization and antibacterial of soybean protein isolate composite film with carvacrol and walnut peel extract

In order to alleviate plastic pollution and to substitute specific conventional polymer packaging, this research deployed biodegradable soy protein isolate (SPI) as a basis to create natural polymer composite films, integrating walnut peel extract (WPE) and carvacrol (CV) for their inherent antibacterial properties. The inhibition rates of the SPI/WPE5%/CV5% composite film on E.coli and S.aureus were 99.66% and 99.52%, the DPPH radical was 73.3% and ABTS radical was 95.5%. The SPI/WPE5%/CV5% composite film also exhibited excellent UV-visible barrier properties. Compared with the pure SPI film, the tensile strength of the SPI/WPE5%/CV5% composite film increased by 89.00%, the water solubility increased by 2.67%, and the water vapor permeability was reduced by 7.69%, While the water contact angle increased by 155.93%. Fourier Transform Infrared Spectroscopy studies possibly indicate that the polyphenol-proteins in the SPI/WPE/CV composite film are bound together by hydrogen bonding. X-ray Diffraction study demonstrated that the crystallinity of the SWC films increased. Scanning Electron Microscope results revealed the surface level and internal molecular structure of the SWC films. Thermal weight analysis showed that after adding WPE and CV, the thermal properties of the SWC films improved. This study explored release of the film and found that the composite film can continuously release polyphenols, which play an antibacterial and antioxidant role.

Ultrasonication-induced re-dispersion of freeze-dried cellulose nanoparticles for improving strength and durability of PAN polymer matrix

Cellulose nanocrystals (CNCs) have acquired considerable attention owing to their noteworthy properties, including high crystallinity, biodegradability, high specific surface area, and excellent mechanical characteristics that alter the inherent features of the polymer matrix upon reinforcement. Typically, CNCs undergo freeze-drying or spray-drying to facilitate handling and dispersion in a hydrophobic polymer medium. Unfortunately, these drying procedures compromise the intrinsic nano-scale properties of CNCs. Therefore, achieving a uniform re-dispersion of dried CNCs is imperative to attain the desired characteristics in the polymer composite. This study specifically focuses on achieving a homogeneous re-dispersion of freeze-dried CNCs within a waste polyacrylonitrile (PAN) matrix through a simple ultrasonication treatment. The enhanced mechanical properties of the PAN polymer matrix validate the impact of ultrasound energy on re-dispersing CNCs. A noticeable improvement in the tensile properties of the composite polymer film is observed when CNC particles are well-dispersed in the PAN matrix. This observation is substantiated through SEM imaging, XRD, and FTIR data of both neat PAN and PAN–CNC composite films. The results affirm that particle dispersion plays a crucial role in augmenting the tensile properties of PAN composite films.

Understanding local interactions in freestanding flexible poly(vinylidene fluoride)/poly(3,4‐ethyelenedioxythiophene):poly(styrelenesulfonate) films using impedance, Raman, and X‐ray absorption spectroscopy

AbstractThe local interaction within poly(vinylidene fluoride)/poly(3,4‐ethyelenedioxythiophene):poly(styrelenesulfonate) (PVDF/PEDOT:PSS) composite films has been explored in this study. Vibrational and impedance spectroscopy were used extensively to investigate the potential interactions within the moieties of PVDF and PEDOT:PSS in the composite. The increased concentration of PEDOT:PSS used as additives enhanced the dielectric constant of the composite films significantly. Both the AC conductivity and the estimated mobility also increased in the composite films with increasing additives. X‐ray absorption spectroscopy gave an insight into the local chain interactions within the polymer composite films. A shift in the C K‐edge toward higher energy confirmed the local interaction of the polymer moieties, suggesting a change in the polymer chain structure due to the possible association of moieties.

A honeycomb-inspired carboxymethyl chitosan-covalently link NH2-black phosphorene biobased cellulose green nanocomposites with tremendously enhancement fire safety and thermal conductivity

Biobased carboxymethyl chitosan-modified black phosphorene (BP-CMC) was prepared through an amidation reaction between amino group functionalized black phosphorene (NH2-BP) and CMC. Density functional theory (DTF) express that the adsorption energy between urea and phosphene is −6.28 eV, indicating a strong interaction. The resulting BP-CMC was further applied to reinforce the mechanical, flame-retardant and thermal conductivity performance of honeycomb cellulose nanofiber (CNF) film via vacuum filtration. Cone calorimetry test (CCT) result exhibits that the introduction of 30 wt% BP-CMC significantly promoted the fire safety of CNF. For instance, a 98.41% reduction in smoke production rate (SPR), 92.00 % decline in CO release and a 61.31% decrease in heat release rate (HRR) were observed compared to neat CNF. Furthermore, Thermogravimetric infrared (TG-IR) indicates a significant decrease in the release of flammable gases. Raman spectra verify that the incorporation of 30 wt% BP-CMC improves the graphitization degree of residual chars, thus limiting the transfer of heat and oxygen. The improvement in fire safety is attributed to the formation of an intumescent flame-retardant system, which is rich in carbon source (CMC), acid source (BP) and gas source (amino). Simultaneously, the introduction of 30 wt% BP-CMC into CNF leads to considerable enhancement in thermal conductivity (up to 17.49 %), thermal diffusion (utmost to 43.45 %) and heat capacity (increased by 19.23 %). Moreover, the 30 wt % addition of BP-CMC into CNF possesses excellent mechanical properties with the improvement of toughness (increased by 143.50 %) and tensile strength (increased by 140.90 %). This strategy not only provides a new strategy for functionalizing BP but also upgrades the application potential of BP nanosheets in the fire safety of polymer composite films.

Effect on thermal, mechanical, and biodegradable properties of plasma‐treated fish scale powder/linear low‐density polyethylene polymer composite films

AbstractIn the present work, we report the effect of low‐temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low‐density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties. It was observed that the tensile strength decreased with the increased loading content of CFSP, and 1% CFSP/LLDPE exhibited the highest tensile strength. To study the effect of low‐temperature plasma treatment, 1% CFSP/LLDP polymer composite with high tensile strength was plasma treated with O2 and SF6 gas before blow film extrusion. The 1% CFSP/LLDPE/SF6‐extruded blown films showed increased thermal decomposition, crystallinity, tensile strength, and modulus. This may be due to the effect of crosslinking by the plasma treatment. The maximum thermal decomposition rate, crystallinity %, tensile strength, and modulus obtained for 1% CFSP/LLDPE/SF6 film were 500.02°C, 35.79, 6.32 MPa, and 0.023 GPa, respectively. Furthermore, the biodegradability study on CFSP/LLDPE films buried in natural soil for 90 days was analyzed using x‐ray fluorescence. The study showed an increase in phosphorus and calcium mass percent in the soil. This is due to the decomposition of the hydroxyapatite present in the CFSP/LLDPE biocomposite.

Electrostatically self-assembled three-dimensional conductive network for highly sensitive and reliable skin-like strain sensor

In recent years, flexible strain sensors have garnered significant attention in industrial manufacturing and daily life. Sensitivity and reliability are two crucial characteristics of flexible strain sensors in practical applications, and they depend on the development of the sensor's internal conductive network. However, the aggregation phenomenon of conductive fillers in the elastic matrix has a serious impact on the construction of a developed conductive network. In this work, we have designed electropositive amino-functionalized carbon nanotubes (CNTs-p) based on the electrostatic self-assembly of electronegative MXene in the aqueous phase. Compared to the use of surfactants, the electrical modulation of carbon nanotubes through chemical bonding modification is more robust and the electrostatic self-assembly with MXene is more stable. CNTs-p and MXene were self-assembled by electrostatic attraction in butyl latex and uniformly dispersed in the latex. Following demulsification, the polymer composite film (MXene&CNTs-p/IIR) with a three-dimensional conductive network was obtained. The skin-like strain sensor, which utilizes the conductive composite film, demonstrates high sensitivity (gauge factor (GF) = 35137 that is among the highest values for the reported strain sensor), remarkable reliability (The signal monitoring capability remains after 15000 cycles), and excellent responsiveness (62 ms). Additionally, the skin-like strain sensor boasts a wide detection range (0–431%) and unprecedented stability, enabling strain sensing functionality in a wide temperature range of -10—100 °C, as well as strong acid (pH = 1) and strong alkali (pH = 11) environment. The preparation of MXene&CNTs-p/IIR provides a safe, environmentally friendly and effective method for improving the sensitivity and reliability of flexible sensors in wearable intelligent electronics and health detection.

An ultrathin and flexible polymer composite film at a low fraction of reduced graphene oxide for Ku-band electromagnetic interference shielding

The development of effective electromagnetic interference (EMI) shielding materials has turned into an extremely important and urgent challenge. The current study presents an ultrathin and flexible polymer, poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite thin film, at a very low loading of reduced graphene oxide (rGO) prepared by a straightforward solvent casting approach for efficient EMI shielding application. The homogenous distribution of rGO sheets throughout the polymer matrix has been verified by applying high-resolution scanning and transmission electron microscopy. To clarify the interfacial relationship between the matrix and filler as well as potential changes in phase, the PVDF-HFP/rGO (PrGO) composite films are further analyzed using X-ray diffraction, Raman spectra, Fourier transform-infrared spectra, and contact angle analysis. The PrGO composite film has a 4.2 GPa Young's modulus and a tensile strength of around 64.8 MPa. The Ku-band frequency has been implemented to evaluate PrGO composite films' EMI shielding ability. The ultrathin PrGO composite film (∼80 µm) revealed an efficient EMI shielding effectiveness (SE) of ∼18.3 dB at a meagre rGO fraction (6.75 wt.%). This efficient EMI SE from ultrathin PrGO composite films is due to the well-connected network of rGO sheets inside the PVDF-HFP matrix. This study demonstrates a scalable and effective way to design an ultrathin, lightweight, and flexible composite film for promising EMI shielding applications in the development of miniaturized electronic devices, and aerospace fields.

Li-Zn alloy patch for defect-free polymer interface film enables excellent protection effect towards stable Li metal anode

Constructing a smart polymer film with favorable lithium (Li) transport capability and mechanical flexibility for suppressing Li dendrite growth is an effective strategy. Unfortunately, the porosity and the swelling of the polymer membrane cannot completely prevent liquid electrolyte from sweeping through the artificial protection film, severely deteriorating the cyclic performance. Herein, we propose a defect-free hybrid film that consists of Li+ conductive lithium polyacrylate (LiPAA) polymer interface layer and Li-Zn alloy patch to tackle the critical problems of traditional polymer composite passivation film. The pinhole leaks of the polymer matrix are self-filled by Li-Zn alloy patches, enhancing the integrity of LiPAA film. Consequently, a defect-free hybrid film is nailed flat against the Li metal anode, exhibiting extraordinary stability in the liquid electrolyte and enabling perfect protection effect. This facile strategy produces a promising anode for next generation Li batteries.

Modelling the piezoelectric effect in a composite polymer film filled with disperse piezoelectric

Mesoscopic modelling of a composite material constituted by an electroneutral polymer (matrix) film filled with micropowder of piezoelectric ceramics (filler) is presented. The calculation scheme resembles that of the RVE (Representative Volume Element) method. The representative element (cell) is a right-angle prism with square cross-section, the height of which is equal to the film thickness. Around the midsection of the prism, there are a few (from 2 to 4) spherical piezoelectric particles positioned close to one another. The length of the base side of the prism is determined from the assumed solid phase content of the composite. To simulate the film, the cells are arranged in a continuous flat layer, inside which they are coupled by means of periodic boundary conditions imposed on their lateral surfaces. To reduce the artifacts of the model, the position of the center of each particle is chosen randomly within the area of the prism cross-section. In the framework of this approach, a low-density polyethylene film with embedded barium titanate particles is considered as an example. One of the surfaces of the film is fixed (no displacements), and the other one is left free. For the characteristics of the particles close to those used in the experiment and the typical matrix material parameters (elasticity moduli, Poisson coefficients, dielectric permittivity), the voltage output (piezoeffect) induced in the film in response to the uniform pressure applied to its free surface is evaluated. It is shown that the electric potential along the thickness of the film is nonuniform: it grows inside the particles and falls down in the interparticle gap. In order to present the results in the form applicative for comparison with the experimental data, for each variant of the system (number of the particles, weight fraction of the solid phase), the calculated values are averaged over a few tens of realizations of the particle positions inside the element.

An alternating copolymer of phenothiazine and ethylenedioxythiophene for perovskite solar cells: effects of flexible and rigid substituent alternation.

Developing p-type polymeric semiconductors with exceptional electrical performance, heat tolerance, and cost-effectiveness is pivotal for advancing the practical application of n-i-p perovskite solar cells. Here, we employed direct arylation polycondensation to synthesize an alternating copolymer of phenothiazine and 3,4-ethylenedioxythiophene, featuring a high glass transition temperature (175 °C). In addition to the alternation of conjugated units within the main chain, the copolymer features alternating flexible (2-octyldodecyl) and rigid (trimethylphenyl) substituents at the nitrogen positions of the phenothiazine moiety. Compared to reference polymers with solely flexible or rigid substituents, the alternating use of these moieties resulted in the polymeric semiconductor composite film with smoother morphology and enhanced hole mobility. By employing this polymer with a distinct distribution of substituents and an innovative main chain structure as a hole transport material, we fabricated perovskite solar cells achieving an average efficiency of 25.1%. These cells also exhibited excellent stabilities under conditions of 85 °C thermal storage and 45 °C operation.

In situ preparation of highly luminescent Sb3+/Mn2+ co-doped Cs2KInCl6 lead-free double perovskites in a PVDF matrix and application to white light emitting diodes and anti-counterfeiting

A strategy for in situ preparation of lead-free double perovskite-based polymer composite film with large area and high efficiency white light emission and its applications.

Hot-pressed Mn-doped Pb((Zr0.3Ti0.7)0.99Mn0.01)O3/polystyrene composites with improved dielectric and energy storage performance

Polymer composite films are superb dielectrics with high energy storage performance. Accordingly, herein we fabricated thick dumbbell-shaped 0–3 composites by incorporating Pb((Zr0.3Ti0.7)0.99Mn0.01)O3 (PMZT) as filler (0 –20% by weight) into a polystyrene (PS) matrix, using a two-step, solvent-free method involving melt mixing and subsequent hot pressing. The effects of processing parameters, acceptor doping in the filler, and filler content on the thermal, dielectric, and energy storage properties of the composites were investigated. IR spectroscopy and X-ray diffraction studies confirm the successful integration of the perovskite PMZT ceramic into the PS matrix. Notably, the composite morphology displayed a uniform distribution of filler particles, devoid of voids or agglomerates, indicating effective filler reinforcement. Mn ions acting as acceptor dopants in the ceramic filler, enhance the dielectric constant of the PMZT/PS composites while significantly minimizing the dielectric loss. The hot-pressing method promotes the alignment of dipoles of the filler particles within the composites, leading to stronger polarization and enhanced overall dielectric and ferroelectric response. Remarkably, the 20 wt% PMZT/PS composite exhibits an increased maximum polarization of 0.42 µC/cm2 and an 83% energy storage efficiency, making it a promising candidate for energy storage application.

STUDYING THE MODIFICATION OF NANOSTRUCTURED POLYURETHANE ELASTOMER/POLYVINYL CHLORIDE BLEND BY LOW-MOLECULAR PLASTICIZERS

The effect of chemical structure of low molecular weight plasticizers (LMWP) on intermolecular interactions and mechanical properties of nanostructured polyurethane elastomer (PU)/polyvinyl chloride (PVC) was investigated. Polymer composite films were prepared by solution casting technique using dimethylformamide (DMF) or by rolling the melt. FTIR data showed a maximum level of intermolecular hydrogen bond degradation for PU or the polymer blend modified with trichloroethyl phosphate (TCEP) due to the formation of H-bonds between NH of rigid urethane/urea fragments of PU elastomer and chlorine of TCEP. The low compatibility of di-(2-ethylhexyl)-о-phthalate (DOP), compared with di-n-butyl-о-phthalate (DBP), and PU elastomer provided a minor effect of plasticizer on intramolecular and interfaсial interactions in PU or polymer blend. The resulting composites are characterized by increased tensile strength in the whole composition range. The results of DSC analysis of melt-rolled blends of PU/PVC modified by DOP had one wide glass relaxation transition range and their thermal and mechanical properties could be controlled by changing the ratio of initial components. The aforementioned results provide new possibilities of manufacturing the novel nanostructured thermoplastic elastomers with improved mechanical properties.

FILM MATERIALS BASED ON POLYVINYL ALCOHOL, FILLED WITH SILVER NANOPARTICLES

In the present work polymeric composite films materials based on polyvinyl alcohol (PVA), glycerol and silver nitrate the conducted composites with high mechanical characteristics were created. In the process of composites drying, glycerol acts as a reducing agent and the formation of silver nanoparticles occurs, moreover the reducing take places at room temperature. The AgNO3 content is varied from 0.01 to 30 wt.%. Taking into account the physical-mechanical and conducting properties of composites, it is established that the optimum content of glycerol in the final material is equal to 30 wt%. The formation of metallic silver was confirmed by an appearance of a surface plasmon resonance band at 420-430 nm in UV spectra and the appearance of two diffraction peaks at 38.17° and 44.15° in X-ray diffraction pattern as well, corresponding to the crystallographic planes (111) and (200) of a face centered cubic lattice of Ag0. Dielectric spectroscopy data show that the increasing of glycerol content up to 30-40 wt.% leads to enhance the conductivity by three orders in comparison with the initial PVA. An increase in the silver content resulted in further rise of the conductivity, reaching value of 5.72 10-6 S/cm at 15 wt.% of silver concentration, at room temperature (20 °C). At 100-120 °С, the conductivity was the highest for the composite with 25 wt.% of AgNO3 - 3.67-3.84 10-4 S/cm. The resulting samples had high physical and mechanical properties: relative elongation of about 400%, tensile strength of 32–36 MPa. Studies of the dynamic light scattering of films solution with Ag NPs showed that the smallest size was for the sample with 0.5 wt.% - 6.3 nm.