Composite Polymer Blends Research Articles

Investigation of structural and conductivity properties of poly(vinyl alcohol)‐based electrospun composite polymer blend electrolyte membranes for battery applications

AbstractSolid polymer electrolyte has attracted great interest for the next generation of electrochemical devices such as batteries, but the low ionic conductivity and poor stability has retarded their commercial acceptance for energy storage devices applications. To overcome these issues, strategies to develop composite polymer electrolytes (CPEs) are drawing interest. Nanocomposite solid polymer blend electrolyte membranes based on poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) of various compositions that contained potassium nitrate (KNO3) as a dopant salt, and Barium Titanate (BaTiO3) as a filler were prepared with various concentrations of filler using electrospinning technique. The structural and complex formations due to interaction of various groups of the prepared composite polymer electrolyte membranes were investigated using X‐ray diffraction (XRD) and Fourier transform infra‐red (FTIR) spectral analysis. The conductivity of the PVA‐PVP‐KNO3‐BaTiO3 polymer electrolyte systems was found to vary between 3.71×10‐9 and 1.99×10‐5 S cm‐1 at 298 K with the increase in filler concentration. The maximum room temperature ionic conductivity (1.99×10‐5 S cm‐1) has been obtained for 9 wt% BaTiO3 doped polymer electrolyte system. The addition of filler also enhanced the thermal stability of the electrolyte. The temperature dependence ionic conductivity of the prepared complexed polymer electrolyte systems appears to obey Arrhenius behaviour.

The Preparation of Monomer Casting Polyamide 6/Thermotropic Liquid Crystalline Polymer Composite Materials with Satisfactory Miscibility.

It is highly expected to develop a simple and effective method to reinforce polyamide 6 (PA6) to enlarge its application potential. This is challenging because of frequently encountered multi-component phase separations. In this paper, we propose a novel method to solve this issue, essentially comprising two steps. Firstly, a kind of poly (amide-block-aramid) block copolymers, i.e., thermotropic liquid crystalline polymer (TLCP)-polyamide 6 (TLCP-PA6), that contains both rigid aromatic liquid crystal blocks, and flexible alkyl blocks were synthesized. It is unique in that TLCP is chemically linked with PA6, which is advantageous in excellent chemical and physical miscibility with the precursors of monomer casting polyamide 6 (MCPA6), i.e., ε-caprolactam. Secondly, such newly synthesized block copolymer TLCP-PA6 was dissolved in the melting ε-caprolactam, and followed by in situ polymerization to obtain composite polymer blends, i.e., MCPA6/TLCP-PA6. The thermodynamic, morphological, and crystalline properties of MCPA6/TLCP-PA6 can be easily manipulated by tailoring the loading ratios between TLCP-PA6 and ε-caprolactam. Especially, at the optimized condition, such MCPA6/TLCP-PA6 blends show an excellent miscibility. Systematic characterizations, including nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimeter (DSC), and polarizing optical microscope (POM), were performed to confirm these statements. In view of these results, it is anticipated that the overall mechanical properties of such PA6-based polymer composites will be satisfactory, which should enable applications in the modern plastic industry and other emerging areas, such as wearable fabrics.

Influence of CeO2as dispersoid in blend poly(styrene‐co‐methylmethacrylate) as electrolyte for lithium‐ion battery

AbstractPoly(styrene‐co‐methylmethacrylate) P(S‐MMA) composite polymer electrolytes are having massive consideration for solid‐state electrochemical devices. There are numerous tactics implement to improve the ambient temperature ionic conductivity such as the addition of plasticizers, the inclusion of nanosize ceramic fillers and blending with the host polymer, which were carried out in this work. The effect of CeO2 on the P(S‐MMA)‐poly(vinylidene fluoride) (25:75 of 27 wt%)‐LiClO4 (8 wt%)‐ethylene carbonate:propylene carbonate (1:1 of 65 wt%) system prepared via a conventional solution casting technique. The as‐prepared polymer membranes were characterized using XRD, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis, SEM and AC impedance analyses. The composite polymer blend gel electrolyte system exhibits high ionic conductivity (2.51 × 10−2 S cm−1) with 6 wt% CeO2 nanofiller at ambient temperature. The conductivity enhancement is due to the presence of a rise in the amorphous content; it is in well concurrence with the XRD results. The optimum electrolyte was used to design the LiFePO4/composite gel polymer electrolyte/Li cell couple in a 2032 type coin cell. It possesses a discharge capacity of 151 mA h g−1 at 0.1 C. © 2021 Society of Industrial Chemistry.

Effects of anti-striping agents on performance of binder and stone matrix asphalt (SMA) mixtures containing polyphosphoric acid/styrene-butadiene rubber composite polymer blends and warm mixture additives

This work evaluated the effect of Anti-Stripping Agents (ASAs) on performance behavior of bitumen and high and intermediate temperature performance of SMA mixtures modified by Poly Phosphoric Acid (PPA), Warm Mix Asphalt (WMA) and Styrene-Butadiene Rubber (SBR) additive. Through this paper, the AC-60/70 and AC-85/100 penetration grade bitumens were used as base bitumen. Moreover, three liquid ASAs (ASA (1), ASA (2), ASA (3)), PPA (1% by weight of bitumen), SBR (2% by weight of binder), and two types of warm mix additives (3% Sasobit and 0.3% Zycotherm) were used as a mixture modifier. For evaluating the performance behavior of bitumen, the rotational viscosity, Dynamic Shear Rheometer, and Bending Beam Rheometer, Multiple Stress Creep Recovery (MSCR), and linear Amplitude Sweep (LAS) tests were implemented. Moreover, Resilient Modulus (Mr), Indirect Tensile Strength (ITS), dynamic creep, wheel track, and Four-Point Beam Fatigue (FPB) tests were performed to investigate the performance of mixture samples. Based on the outcomes of the MSCR test, the utilization of SBR/PPA additive and ASAs decreased the Jnr value. Among modified binders, the binders modified by ASA (2) have the lowest Jnr value followed by binders modified by ASA (1) and ASA (3). According to the outcomes of LAS test, the utilization of ASAs leads to increase in the fatigue life of the original binder. According to the outcomes, the utilization of WMA additives and ASAs caused the Mr, ITS, rutting resistance, and fatigue life to increase. Among ASAs, the ASA (2) has the greatest influence on enhancing the performance of mixtures. Based on results, Sasobit additive has a better effect than Zycotherm on enhancing the properties of samples.

Ion dynamics and dielectric relaxation behavior of PVA-PVP-NaI-SiO2 based nano-composites polymer blend electrolytes

In this paper we have reported the loading effect of SiO2 nano-particles on the electrical transport properties and dielectric relaxation behavior of the PVA-PVP-NaI based nano composite polymer blend electrolytes (NCPBEs). Solution cast technique has been used for the preparation of PVA-PVP-NaI-SiO2 based NCPBE films. AC impedance spectroscopic technique is used for the study of electrical conductivity and dielectric properties. The frequency dependence of AC conductivity with different SiO2 concentration for all prepared NCPBEs obeys the Jonscher power law (JPL) with exponent, n ≥ 1. The dielectric permittivity (ε′&ε″), electric modulus (M′&M″) vs. frequency plots at different concentrations and temperatures were reported. Mobility (μ), dc conductivity (σdc) and total number of charge carriers (N) were estimated and found that mobility varies with the SiO2 concentration. Sample containing 0.6 wt% of SiO2 shows optimum dc conductivity, σdc ~5.07 × 10−6 S/cm with μ ~4.60 × 10−7 and N ~6.98 × 1021. Dielectric relaxation peaks have been observed for all samples and relaxation time (τ) is minimum for 0.6 wt%SiO2 based NCPBE film.

Repelling Polysulfides Using White Graphite Introduced Polymer Membrane as a Shielding Layer in Ambient Temperature Sodium Sulfur Battery

AbstractHerein, a strategy is demonstrated to effectively control the sodium polysulfide dissolution using composite polymer blend membrane. The sufficient interconnected pores in the white graphite introduced polymer blend membrane plays a multifunctional role as an ion selective membrane, evident from the ionic conductivity of 10−3 S cm−1 facilitating the movement of sodium ions and the presence of boron and nitrogen in white graphite acts as an effective absorbent to trap sodium polysulfides. The electrochemical testing reveals significant improvement of about 87.6% in specific capacity when compared to the cell without white graphite@ polymer membrane. Also, the cell exhibits an excellent cycling stability with a capacity retention of 83.1% at the end of 500 cycles. Other than the performance enhancement, the self‐discharge battery is significantly reduced using the developed membrane. The better performance of the room temperature sodium sulfur battery is attributed to the physical and chemical confinement of composite polymer membrane which is also evident from the post analysis study. This is the first attempt of utilizing composite polymer membrane as a blocking layer in room temperature sodium sulfur batteries and is promising for the construction of high performance batteries.

Experimental and Numerical Investigation of Lower Limb Prosthetic Foot made from Composite Polymer Blends

Experimental and Numerical Investigation of Lower Limb Prosthetic Foot made from Composite Polymer Blends

Influence of Experimental Parameters on Friction and Wear Mechanisms of PA66/PTFE Blend Reinforced with Glass Fiber

Polymer blend of composition 80 wt% polyamide 66/20 wt% polytetraflurotheylene (PA66/PTFE) was selected as a matrix and reinforced with different weight percentage of short glass fibers (SGF). These composites were prepared by melt mix method using twin screw extruder followed by injection molding. The tribological behaviors were tested by using pin on disc machine by varying the different experimental parameters. The friction and wear mechanisms were studied as a function of sliding velocity, sliding load, and distance. The effect of fiber loading lowered the wear volume loss of SGF filled PA66/PTFE blend. The least frictional coefficient of 0.24 was obtained for 20 wt% of SGF in the blend. However, the wear resistance was not apparently improved by SGF loading in the experimental range for comparison with unfilled PA66/PTFE blend. The worn surfaces of specimen were examined by scanning electron microscopy photographs. The observations revealed that the frictional behavior was a function of development and formation of transfer film. Matrix wear and fiber wear were the result of frictional mechanism. The critical wear volume of PA66/PTFE/SGF composites was the contribution of both matrix and fiber wear. The abrasive nature of SGF was also one of the important factor for frictional behavior.

Efficiency and Stability Enhancement of Quasi-Solid-State Dye-Sensitized Solar Cells Based on PEO Composite Polymer Blend Electrolytes

The composite polymer electrolyte consisting of poly (ethylene oxide) (PEO), KI, I2 and TiO2 was blended with low molecular weight poly (ethylene glycol) (PEG) and (PEG-MA)-Ru. The SEM images of these blended PEO electrolytes showed better dispersion of materials and the electrochemical impedance spectroscopic study showed an increase in conductivity compared to that of composite PEO electrolyte. These results were consistent with enhanced efficiency of DSSCs using these blended PEO electrolytes. The energy conversion efficiencies of DSSCs using composite PEO-PEG, PEO-(PEG-MA)-Ru and PEO-PEG-(PEG-MA)-Ru polymer blend electrolytes were 5.47, 5.05 and 5.28, respectively compared to 4.99 of DSSC using composite PEO electrolyte. The long-term storage of unsealed DSSCs at room temperature for 93 days demonstrated that the cell efficiency gradually decreased to 0.49-1.88%. DSSCs assembled with composite polymer blend electrolyte showed a slower decrease than that of DSSC using composite PEO electrolyte. It was found that the composite PEO-PEG-(PEG-MA)-Ru polymer blend electrolyte of 1.0:0.1:0.1 weight ratio gave the best improvement in stability of DSSCs.

Effects of ceramic filler in poly(vinyl chloride)/poly(ethyl methacrylate) based polymer blend electrolytes

Abstract Effects of nano-ceramic filler titanium oxide (TiO2) have been investigated on the ionic conductance of polymeric complexes consisting of poly(vinyl chloride) (PVC)/poly(ethyl methacrylate) (PEMA), and lithium perchlorate (LiClO4). The composite polymer blend electrolytes were prepared by solvent casting technique. The TiO2 nanofillers were homogeneously dispersed in the polymer electrolyte matrix and exhibited excellent interconnection with PVC/PEMA/PC/LiClO4 polymer electrolyte. The addition of TiO2 nanofillers improved the ionic conductivity of the polymer electrolyte to some extent when the content of TiO2 is 15 wt%. The addition of TiO2 also enhanced the thermal stability of the electrolyte. The changes in the structural and complex formation properties of the materials are studied by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The scanning electron microscope image of nano-composite polymer electrolyte membrane confirms that the TiO2 nanoparticles were distributed uniformly in the polymer matrix.

Influence of Barium Titanate on poly(vinyl pyrrolidone)‐based composite polymer blend electrolytes for lithium battery applications

Nanocomposite polymer blend electrolytes based on poly (ethylene oxide), poly (vinyl pyrrolidone) that contained lithium perchlorate as a dopant, propylene carbonate (PC) as a plasticizer and Barium Titanate (BaTiO3) as a filler were prepared for various concentrations of BaTiO3 using solvent casting technique. The structural and complex formations of the composite electrolyte membranes were confirmed by X‐ray diffraction and FTIR analysis. The addition of BaTiO3 nanofillers improved the ionic conductivity of the polymer electrolytes to some extent when the content of the BaTiO3 is 10 wt%. The addition of BaTiO3 also enhanced the thermal stability of the electrolyte. The surface morphology of the sample having a maximum ionic conductivity was studied by AFM. Molecular motion in the polymeric media was supported by fluorescence studies. The charge transfer arises between the polymer blend and Li‐ions were confirmed by UV‐Vis analysis. POLYM. COMPOS., 36:302–311, 2015. © 2014 Society of Plastics Engineers

The influence of electrospun scaffold topography on endothelial cell morphology, alignment, and adhesion in response to fluid flow

Bioengineered vascular grafts provide a promising alternative to autografts for replacing diseased or damaged arteries, but necessitate scaffold designs capable of supporting a confluent endothelium that resists endothelial cell (EC) detachment under fluid flow. To this end, we investigated whether tuning electrospun topography (i.e., fiber diameter and orientation) could impact EC morphology, alignment, and structural protein organization with the goal of forming a confluent and well-adhered endothelium under fluid flow. To test this, a composite polymer blend of poly(ε-caprolactone) (PCL) and type I collagen was electrospun to form scaffolds with controlled fiber diameters ranging from approximately 100-1,200 nm and with varying degrees of fiber alignment. ECs were seeded onto scaffolds, and cell morphology and degree of alignment were quantified using image analysis of fluorescently stained cells. Our results show that ECs form confluent monolayers on electrospun scaffolds, with cell alignment systematically increasing with a larger degree of fiber orientation. Additionally, cells on aligned electrospun scaffolds display thick F-actin bundles parallel to the direction of fiber alignment and strong VE-cadherin expression at cell-cell junctions. Under fluid flow, ECs on highly aligned scaffolds had greater resistance to detachment compared to cells cultured on randomly oriented and semi-aligned scaffolds. These results indicate that scaffolds with aligned topographies may be useful in forming a confluent endothelium with enhanced EC adhesion for vascular tissue engineering applications.

Li-ion conduction on nanofiller incorporated PVdF-co-HFP based composite polymer blend electrolytes for flexible battery applications

Composite polymer electrolytes (CPE) composed of Poly (vinyl acetate) (PVAc), poly (vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP), barium titanate (BaTiO3) nanofiller, lithium tetrafluroborate (LiBF4), ethylene carbonate (EC) and propylene carbonate (PC) were prepared using simple solution casting method. The BaTiO3 nanofillers were homogeneously dispersed in the polymer electrolyte matrix and exhibited excellent interconnection with PVAc/PVdF-co-HFP/EC/PC/LiBF4 polymer electrolyte. The addition of BaTiO3 nanofillers improved the ionic conductivity of the polymer electrolytes to some extent when the content of the BaTiO3 is 8wt.%. The addition of BaTiO3 also enhanced the thermal stability of the electrolyte. The structural and complex formations of the composite electrolyte membranes were confirmed by X-ray diffraction and FTIR analysis, respectively. Surface morphology of the samples was depicted using scanning electron microscope and atomic force microscope studies.

EDLC with UV-Cured Composite Polymer Electrolyte Based on Poly[(ethylene glycol) Diacrylate]/Poly(vinylidene fluoride)/Poly(methyl methacrylate) Blends

UV-cured poly[(ethylene glycol) diacrylate]-poly(vinylidene fluoride)-poly(methyl methacrylate) composite polymer blends containing 1.0 M of lithium hexafluoro phosphate (LiPF 6 ) as liquid components were employed as a gel-type composite polymer electrolyte cast onto nonwoven fabric supports for an electric double layer capacitor (EDLC). The electrodes were prepared by dip-coating method using activated carbon powder with a high specific surface area of 1908 m 2 g - 1 for EDLC. The EDLC composed of the activated carbon electrode, the UV-cured PEGDA/PVdF/PMMA blend film cast onto nonwoven fabric supports and the activated carbon electrode showed good mechanical strength and predominant electrochemical performances.

The characteristic properties of poly(methyl methacrylate)/polystyrene core-shell composite polymer latex

In this study, the poly(methyl methacrylate/polystyrene (PMMA/PS) core-shell composite latex was synthesized by the method of soapless seeded emulsion polymerization. The morphology of the PMMA/PS composite latex was core-shell structure, with PMMA as the core and PS as the shell. The core-shell morphology of the composite polymer latex was found to be thermally unstable. Under the effect of thermal annealing, the PS shell region first dispersed into the PMMA core region, and later separated out to the outside of the PMMA core region. This was explained on the basis of lowing interfacial tension between the PMMA and PS phases owing to the interpenetration layer. The interpenetration layer, which was located at the interface of the core and shell region, contained graft copolymer and entangled polymer chains. Both the graft copolymer and entangled polymer chains had the ability to lower the interfacial tension between the PMMA and PS phases. Also, the effect of thermal annealing on the morphology of commercial polymer/composite latex polymer blends was examined. The result showed that the core-shell composite latex had the ability to enhance the compatibility of the components of polymer blends. The compatibilizing ability of the core-shell composite latex was better than that of a random copolymer. Moreover, the effect of the amount of core-shell composite latex on the morphology of the polymer blend was investigated. The polymer blends, which contained composite latex above 50% wt, showed the morphology of a double sea-island structure. In addition, the composite latex was completely dissolved in solvent to destroy the core-shell structure and release the entangled polymer chains, and then dried to form the entangled free composite polymer. The entangled free composite polymer had the ability to enhance the compatibility of the components of the polymer blend as usual. The weight ratio 3/7 commercial polymer/entangled free composite polymer blend showed the morphology of the phase inversion structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 312–321, 2003

Ambient temperature solid polymer electrolyte devices

Poly(ethylene oxide) based solid polymer electrolytes with lithium bis-perfluoro-acyl-imide and lithium bis-perfluoro-sulfonylimide plasticizer salts have been investigated by complex impedance analysis, differential scanning calorimetry and electrochemical performance in the Li/V 6O 13 electrode couple environment. Poly(ethylene oxide)-poly(ethylene glycol) based composite polymer blends with LiCF 3SO 3 salt were also studied as possible ambient temperature electrolytes. A third group of polymer electrolytes based on lithium salts doped into non-aqueous gels were found to possess an ionic conductivity of 4.5×10 −4 S cm at 22°C. The material was used as an electrolyte in the fabrication of a thin film electrochemical cell (6.5 cm 2 area) with the Li/V 6O 13 electrode couple. Preliminary results indicated a good reversibility, but interfacial polarization was significant.