Solution Blending Method Research Articles

Effect of Environmental Temperature on the Insulating Performance of Epoxy/MgO Nanocomposites

This article reports on the development of nano-MgO/epoxy resin composites with various mass ratios via a solution blending method. The influence of MgO nanofillers on the thermal properties and the effect of environmental temperature on the insulating properties of the composite material were analyzed. The results show that the thermal conductivity of the composites increased with an increasing MgO nanofiller content. Compared with the pure epoxy resin, the thermal conductivity increased by 75% when the content of MgO nanoparticles was 7%. The volume resistivity first increased and then decreased with an increasing doping concentration. The volume resistivity increased by 26.8% in comparison with the pure epoxy resin when the content of MgO nanoparticles was 1%, while its dielectric constant and dielectric loss increased with temperature. In addition, the dielectric constant increased and the dielectric loss first decreased and then increased with an increasing MgO nanoparticle content. Moreover, the MgO composites changed from a glassy to a rubbery state, and the breakdown strength was significantly reduced with an increased temperature. When the temperature was higher than the glass transition temperature, the breakdown strength decreased by 51.3% compared with the maximum breakdown strength at 20 °C. As the content of MgO nanoparticles increased, the breakdown strength of the composite first increased and then decreased. The highest breakdown strength was achieved when the content of MgO nanoparticles was 1%, which was 11.1% higher than that of the pure epoxy resin. It was concluded that the MgO nanofillers can significantly improve the thermal properties of epoxy composites and their insulation performance at high temperatures.

Improving Photophysical Properties of White Emitting Ternary Conjugated Polymer Blend Thin Film via Additions of TiO2 Nanoparticles.

The effect of TiO2 nanoparticles on the photophysical properties of ternary conjugated polymer (CP) blends of poly(9,9-dioctylfluorene-2,7-diyl) (PFO), poly 9,9-dioctylfluorene-alt-benzothiadiazole (F8BT) and poly(2-methoxy-5(2-ethylhexyl)-1,4 -phenylenevinylene (MEH-PPV) thin films was investigated. This ternary blend used a fixed amount of PFO as the donor with MEH-PPV and F8BT in various ratios as the acceptors. The solution-blending method and the spin-coating technique were used to prepare the blends and the thin films, respectively. Through efficient Förster Resonance Energy Transfer (FRET), the desired white emission was achieved with PFO/0.3 wt.% F8BT/0.5 wt.% MEH-PPV ternary blend thin film. Additions of nanoparticles up to 10 wt.% dramatically intensified the white emission which then dimmed at higher contents due to agglomerations. The current density–voltage characteristics of the nanocomposite thin films exhibited dependency on the content and distributions of the nanoparticles. Finally, a possible underlying mechanism for the intensification of emission is proposed.

Study on the properties of PLA/PBAT composite modified by nanohydroxyapatite

Poly(lactic acid) (PLA) and poly(butylene adipate-Co-terephthalate) (PBAT) show high and excellent biocompatibility, which are promising materials used in bone tissue engineering field. In this research, n-HA/PLA/PBAT/MCC composites were prepared by solution blending method. Nano hydroxyapatite (n-HA) was used as nucleation, and microcrystalline cellulose (MCC) was added to improve the degradation performance of the materials. Compared with the composite without n-HA, the crystallinity of the composites with 6% n-HA was increased by 62%. The scanning electron microscopy (SEM) and the transmission electron microscopy (TEM) showed that the n-HA was evenly dispersed in the composites when the addition ration of n-HA was lower than 6%, while obvious agglomeration of n-HA appeared at the addition ratio of 10%. The tensile test demonstrated that the tensile strength of the composites with different addition ratio transcended the needs of bone tissue engineering materials. The introduction of n-HA in obtained composites simulated the composition and structure of native bone, which suggested a potential utility and application prospect in bone tissue engineering.

Polyurethane–POSS hybrid materials: by solution blending and in-situ polymerization processes

Polyhedral oligomeric silsesquioxane (POSS) is a nanostructured soft material that tremendously influences the properties of polymers. This paper delineates the preparation of polyurethane–POSS hybrid materials by physical blending and in-situ polymerization, and studies their properties. In the physical blending method, a polyurethane (BDO–PU) was prepared by using polycaprolactone diol (PCL-diol) as a soft segment, 4,4 $$^\prime $$ -methylenebis(phenyl isocyanate) (MDI) as a diisocyanate and 1,4-butanediol (BDO) as a chain extender. The PU–POSS hybrid material (BDO–PU/POSS) was then prepared by the dispersion of POSS (octahydroxy POSS) molecules in the synthesized BDO–PU matrix by the solution mixing method. In the in-situ polymerization method, POSS–PU and POSS–BDO–PU hybrid materials were prepared using POSS and the combination of POSS and BDO as a crosslinker or a chain extender. The formation of PU and PU–POSS hybrid materials was confirmed by Fourier transform infrared and differential scanning calorimetry analyses. The introduction of octahydroxy POSS molecules into the PU matrix resulted in a reduction of glass transition temperature ( $$T_{\mathrm {g}})$$ . However, POSS–PU hybrid materials prepared by the in-situ polymerization method had significantly less $$T_{\mathrm {g}}$$ compared to the hybrid materials prepared by the solution or physical blending method. The incorporation of POSS molecules by using the in-situ polymerization process resulted in an increase in the surface hydrophobicity (water contact angle, WCA $$=$$ 125 $$^{\circ }$$ ) compared to the same prepared by using the solution blending process (WCA $$=$$ 106 $$^{\circ }$$ ). Moreover, the WCA values of all hybrid materials (WCA $$=$$ 106–125 $$^{\circ }$$ ) are much higher than those of the pristine BDO–PU (WCA $$=$$ 84 $$^{\circ }$$ ). The higher WCA value of the hybrid materials is due to the combined effect of the hydrophobic nature of POSS molecules as well as the increased surface roughness, as evidenced by the AFM 3D images. The hybrid materials prepared by the in-situ polymerization method exhibited improved mechanical and thermal properties compared to those prepared by the solution blending method.

Electronic tongue and cyclic voltammetric sensors based on carbon nanotube/polylactic composites fabricated by fused deposition modelling 3D printing.

In this work, 3D printed electrodes fabricated by blending Polylactic acid (PLA) with carbon nanotube (CNT), CNT/copper (Cu), CNT/zinc oxide (ZnO) composites were applied as cyclic voltammetric sensors for electronic tongue analysis. Porous rectangular rod-shape electrodes were fabricated by fused-deposition-modelling 3D printing of the CNT-based composites produced by a solution blending method. The physical and chemical properties of 3D printed electrodes were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, four-point-probe electrical tests and thermoelectric measurements. The characterization results confirmed uniform distributions of CNTs, Cu particles and ZnO nanorods in the composites and high electrical conductivity of interconnected CNT networks. The additions of Cu and ZnO nanostructures slightly modified the electrical conductivity but significantly changed thermoelectric properties of the material. Cyclic voltammetric (CV) data demonstrated satisfactory stability of the composite materials under corrosive CV conditions. In addition, Cu and ZnO additives provided distinct electrochemical behaviors towards K4Fe(CN)6, H2O2 and nicotinamide adenine dinucleotide. Principal component analysis of CV features could effectively distinguish the three chemicals with various concentrations, illustrating the possibility to apply 3D printed CNT/PLA-based electrodes for electronic tongue applications.

High-strength, flexible and cycling-stable piezo-resistive polymeric foams derived from thermoplastic polyurethane and multi-wall carbon nanotubes

In this work, high strength, flexible and cycling-stable piezoresistive thermoplastic polyurethane (TPU)/multi-wall carbon nanotubes (MWCNTs) composite foams were fabricated by a solution-blending method and supercritical carbon dioxide (ScCO2) foaming process. The microcellular structure (1–10 μm) of the TPU/MWCNTs composites enhanced the energy storage and reduced the conductive percolation threshold. The compressive strength and compressive modulus of the composites were 1.05 MPa and 3.79 MPa. Percolation threshold of the foamed composites decreased from 0.90 vol% to 0.31 vol%. The prepared TPUC5.0 foam (the content of MWCNTs is 5%) had high sensitivity, wide strain range, and stable resistance. The piezoresistive current was relatively stable, and showed high repetitive force-electric conversion behavior in 1000 cycles. Thus, polymeric foams are suitable for real-time monitoring of human foot movement using wearable strain sensors.

High-performance silver nanowire-based thermopolyurethane flexible conductive films

With the unique flexibility or ductility, and efficient low-cost manufacturing process, flexible electronic devices have attracted a growing interest in scientific research and industry with applications in wearable electronic devices, stretchable antennas, flexible displays, and energy devices. Flexible conductive film (FCF), which functionalizes in building connections between different components of the devices, is key constitutions in flexible devices. We prepared the flexible conductive film with a diameter of approximately 60 nm and a length of 20 μm of silver nanowires (AgNWs) as the fillers and thermopolyurethane (TPU) as the matrix by solution blending and tape casting method. Further, self-made fluorinated decyl polyhedral oligomeric silsesquioxane (F-POSS) as hydrophobic layer was deposited on the AgNWs-TPU conductive film by immersing method. We systematically studied the properties of electronic conductivity, electrothermal response and infrared radiation (IR) thermal response performances, and superhydrophobic performance of AgNWs-TPU conductive films. The experimental results reveal that as the mass content of AgNWs reaches 30 wt%, the film displays good conductivity, and the resistivity of the film with 40 wt% AgNWs is 0.07 Ω·mm. AgNWs-TPU conductive film has good electrothermal response and IR thermal response performances. The water contact angle of the AgNWs-TPU conductive film with superhydrophobic layer reaches 155.29° ± 1.03 and superhydrophobic AgNWs-TPU conductive film slightly improves the reliability and tensile strength of the AgNWs-TPU conductive film. Our experimental results indicate that the superhydrophobic flexible conductive films prepared in this experiment can be applied to wearable flexible devices.

Effect of organo-smectite clays on the mechanical properties and thermal stability of EVA nanocomposites

Ethylene vinyl acetate (EVA) nanocomposites containing hydrophobic organo-clays were prepared by a solution blending method to investigate the role of organic modifiers stabilized in the interlayer space of host clays on the thermal stability and mechanical strength of EVA. The smectite clays such as Mt. (Na-montmorillonite), Mica (Na‑fluorine mica), and Ht (Na-hectorite) were used as the host with different particle sizes, but hydrophobically modified by intercalating the long chained alkylammonium surfactants like cetyltrimethylammonium (CTA) bromide, and dimethyldistearylammonium (DMDSA) bromide to form organo-clays. Thus, prepared organo-clays were dispersed homogeneously in a toluene solution of EVA, and then the toluene was evaporated to obtain the organo-clay/EVA nanocomposites. According to the powder XRD analyses for all the nanocomposites, the CTA-clays were better exfoliated and dispersed in EVA matrix than the DMDSA-ones. Among three CTA-clay/EVA nanocomposites, the CTA-Mica/EVA one was determined to be the best in terms of thermal stability compared to the other two nanocomposites, CTA-Mt/EVA and CTA-Ht/EVA. The thermal stability of the CTA-Mica/EVA nanocomposite was significantly improved by ~38 °C, compared to that of the pristine EVA. Upon increasing the CTA-Mica loading concentration up to 12 wt% in EVA matrix, the Young's modulus and tensile strength of the EVA nanocomposites were increased up to 54% in maximum. It is, therefore, suggested that the CTA-Mica is a potential nanofiller for enhancing the thermal stability and mechanical properties of EVA.

Electrochemical inspection of polypyrrole/chitosan/zinc oxide hybrid composites

AbstractPolymer nanocomposite composed of polypyrrole, chitosan, and zinc oxide nanoparticles has been synthesized and it has been evaluated for various electrochemical aspects of the current electrochemical industry. The polypyrrole (PPy) was synthesized by the chemical oxidative polymerization reaction by employing ammonium persulfate as oxidizing agent. Composites of polypyrrole/chitosan (PPy/Chy) and polypyrrole/chitosan/ZnO (PCZ) composites were synthesized by the solution blending method. Detailed structural, morphological, thermal characterization of PPy, PPy/Chy, and PCZ were performed to characterize the specific features of the systems. The composites exhibit better thermal stability and high surface area and the addition of ZnO nanoparticle increase the crystallinity of the composite. Electrochemical characterization of the ITO electrodes modified with PPy, PPy/Chy, and PCZ were performed using cyclic voltammetry, electrochemical impedance spectroscopy, and amperometry techniques. The present study highlights the role of a bio‐compatible material with high surface area and conductive constituent for designing of various high performing electronic noninvasive sensors, biosensors, and so forth.

Flexible electrothermal polymer film based on reduced graphene oxide–water polyurethane

In this paper, waterborne polyurethane (WPU) conductive films incorporated with reduced graphene oxide (RGO) as conductive fillers were prepared by solution blending and tape casting method. The electrical conductivity, thermal conductivity and microstructures of the composite films were systematically investigated. The experimental results demonstrate that the electrical conductivity and thermal conductivity of the RGO–WPU composite films first increased then decreased with the increase of the RGO content. The resistivity of composite film with 7% RGO reaches to the smallest that is about [Formula: see text], and the thermal conductivity of the composite film with 7% graphene was about 0.29 W.m.K[Formula: see text], which an increase of 70% compared with pure WPU. The electrical conductivity of the composite film decreased with the increase of the original concentration of WPU solution and thickness of the composite film. As film heater, the composite film displayed effective and rapid heating at low input voltages owing to the good conductivity. With an input voltage was in the range of 10–24 V, the film took less than 30s to reach a steady-state temperature, demonstrating the fast response of the composite film heater and suitable for applications in the field of the fast temperature switching with low input voltages as flexible electrothermal heater.

The Effect of Blending Methods on the Properties of PLA/Gr Nanocomposites

Polymer nanocomposites based on polylactic acid (PLA) and graphene (Gr) were blended via melt blending and solution mixing. The properties of hardness and melt flow index (MFI) were investigated with variables of Gr loading from 0.5–2.0 wt.% and the effect of poly(ethylene glycol) (PEG) as plasticizer. The PLA/Gr nanocomposites exhibited higher hardness compared with neat PLA for both methods of nanocomposites preparation which were due to stiffness effect from nanofiller. The loading of PEG in the PLA nanocomposites resulted in the slightly decreasing of hardness. The hardness of PLA and PLA nanocomposites obtained from melt blending were higher than hardness from solution mixing where 2.0 wt.% Gr loading in PLA exhibited maximum value which was 83.1 Shore D. The significant improvement on the MFI could be seen with plasticizer loading compared to unfillled PEG in PLA blends obtained from both methods. Again, the MFI values of PLA/Gr showed from melt blending were higher than exhibited from solution blending method. The highest MFI was 70.6 g/10 min, obtained from 0.5 wt.% Gr loading in PLA/PEG/Gr nanocomposite. The morphology study from Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the interfacial interaction and homogeneity of Gr in PLA in order to enhance the hardness and MFI properties as discussed above.

Enhanced Antistatic and Self-Heatable Wearable Coating with Self-Tiered Structure Caused by Amphiphilic MXene in Waterborne Polymer.

The antistatic and self-heatable flexible coating is highly desired for next-generation multifunctional clothing. MXene is a promising filler that possesses an excellent conductivity, an efficient photothermal conversion, and an outstanding compatibility with the waterborne polymer. In this study, MXene was integrated with waterborne polyacrylate by a solution-blending method. The polyacrylate/MXene composites display a self-tiered structure, and the composite coated leather possesses a surface resistivity of 7.85 × 109 Ω with 2 wt % loading, satisfying the B-level of the antistatic standard. The polyacrylate/MXene-0.5 wt % shows a higher temperature increase of 46.9 °C than that of pure polyacrylate after being irradiated by a 275 W IR light for 5 min, and the surface temperature of polyacrylate/MXene-0.5 wt % composite coated leather is 5.4 °C higher than that of polyacrylate coated leather after being irradiated by sunlight for 30 min. The tensile strength of the polyacrylate/MXene-1 wt % composite is increased by 28.3% compared with that of pure polyacrylate. All of the results prove its promising application in the multifunctional coating. Moreover, amphiphilic MXene was produced by changing the etching degree, which resulted in a self-tiered structure of the polyacrylate/MXene composite owing to the improved interfacial activity of MXene. The amphiphilic MXene possesses a decreased surface tension and can serve as a stabilizer for a Pickering emulsion, which suggests novel routes for constructing a multifunctional polymer/MXene composite.

Comparative studies of the mechanical and thermal properties of clay / copolymer nanocomposites synthesized by two in-situ methods and solution blending method

In this study, copolymer/clay nanocomposites were prepared by two different methodologies, the in-situ method and solution blending method. Comparative analyses of mechanical and thermal properties of the nanocomposites fabricated by the two different methods were performed. The solution blending method was found to be an efficient technique to obtain nanocomposites with uniform dispersion of the organoclay loading of up to 10 wt%, simple and fast. On the other hand, the in-situ method produced nanocomposites with good exfoliation and high thermal stability, whereas solution blending method produced materials with good mechanical properties compounds in the nano/clay intercalation and high thermal stability.

Preparation and properties of methyl- and cyclohexylsilsesquioxane oligomers as organic–inorganic fillers

The preparation of oligosilsesquioxanes from methyltrimethoxysilane and cyclohexyltrimethoxysilane for use as organic–inorganic fillers is reported. These oligomers were characterized by molecular weight, nuclear magnetic resonance analyses, and Fourier-transform infrared spectroscopy. The poly(methyl methacrylate) nanocomposites containing oligosilsesquioxanes were prepared by two methods: (i) the solution blending method and (ii) the solution–melt blending method. The solution–melt blending method was found to be a superior method for improving the thermal and mechanical properties of PMMA by intermolecular interaction between oligosilsesquioxanes fillers and PMMA.

Cost-effective polyvinylchloride-based adsorbing membrane for cationic dye removal

The current study focused on the preparation of low-cost PVC-based adsorbing membrane. Metakaolin, as available adsorbent, was embedded into the PVC matrix via solution blending method. The as-prepared PVC/metakaolin mixed matrix membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM), pure water permeability and contact angle measurements. The results confirmed the improvement of PWP and hydrophilicity due to the presence of metakaolin in the PVC matrix. Additionally the structure of PVC membrane was changed due to the incorporation of metakaolin in the polymer matrix. The static adsorption capacity of all samples was determined through dye removal. The effect of metakaolin dosage (0-7%) and pH (4, 8, 12) on dye adsorption capacity was investigated. The results depicted that the highest adsorption capacity was achieved at pH of 4 for all samples. Additionally, adsorption data were fitted on Langmuir, Freundlich, and Temkin models to determine the appropriate governing isotherm model. Finally, the dynamic adsorption capacity of the optimum PVC/metakaolin membrane was studied using dead-end filtration cell. The dye removal efficiency was determined for pure PVC and PVC/metakaolin membrane. The results demonstrated that PVC/metakaolin mixed matrix membrane had a high adsorption capacity for dye removal from aqueous solution.

Heat tolerant epoxy-amine functionalized graphene oxide composites for insulation applications

Heat tolerant polymers are in much demand in electrical, structural, and electronic packaging applications. This article reports on a comparison of epoxy composites reinforced with graphene oxide (GO) and amine-functionalized GO (AGO) on their dielectric properties and adhesive strength in the temperature range of 30–110 °C. GO was synthesized using the modified Hummers method and functionalized with amine functional group using hexamethylenediamine (HMDA) and confirmed by Raman spectroscopy. Various filler concentrations (0.2–0.6 wt.%) of GO/AGO epoxy nanocomposites were prepared using the solution blending method and analyzed using a dynamic mechanical analyzer (DMA), impedance spectroscopy, and the single lap shear (SLS) test. Studies showed AGO reinforced epoxy composites outperforming than neat epoxy and GO-epoxy composites for all the compositions. The optimum concentration of AGO was found to be 0.4 wt.% based on its relative permittivity, dielectric loss and retention of adhesive strength up to 90 °C. The percentage of cohesive area on the fractured surface of SLS tested AGO was ∼1.4 and ∼3 times better than that of GO-epoxy and neat epoxy, respectively. The higher strength retention of AGO-epoxy nanocomposites is suitable for high-temperature insulation applications as adhesive coatings.

Polyvinylidene fluoride (PVDF)-poly(methyl methacrylate) (PMMA)-expanded graphite (ExGr) conducting polymer blends: Analysis of electrical and thermal behavior

Polyvinylidene fluoride (PVDF)-20 wt% poly (methyl methacrylate) blend has been synthesized by solution blending method. Expanded graphite has been synthesized by microwave irradiation of commercial expandable graphite. With varying concentration of expanded graphite (ExGr) in PVDF-20 wt% PMMA, series of blends are synthesized. The electrical percolation threshold has been observed to be less than 1 wt% ExGr which is due to the formation of graphite nanosheets. The conducting blend system exhibits typical percolation behavior. The thermogravimetric analysis shows two step degradation in PVDF-20 wt% PMMA blend system. This is due to the individual degradation of PMMA and PVDF main chains respectively. The thermal stability of the blend system with 1 wt% ExGr incorporation in PVDF-20 wt% PMMA is increased by 11 °C corresponding to main chain degradation of PVDF. The result proves existence of strong interaction between ExGr particles and the polymer. The DSC analysis shows very clearly the existence of electroactive gamma phase both in PVDF-20 wt% PMMA with and without ExGr particles as there is an additional high temperature melting peak apart from that of the melting peak at 167 °C. This result is confirmed through XRD also. The blend system is characterized by XRD, TGA, DSC and FTIR.

Preparation and characterization of hexamethylenediamine-modified graphene oxide/Co-polyamide nanocomposites

The hexamethylenediamine-modified graphite oxide/Co-polyamide (GO-HMD/CO-PA) nanocomposites were successfully produced by solution blending method. X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy analyses revealed that GO with a large number of oxygen-containing functional groups was successfully obtained by a modified Hummer’s method. For GO-HMD, the amino and amide bonds were introduced into the GO sheets, making the sheets more incompact, fluffy, and irregular. GO-HMD with a content of less than 1 wt% could be uniformly dispersed in the CO-PA matrix. A series of analysis indicated that the tensile strength, yield strength, and elongation at break of 0.4 wt% GO-HMD/CO-PA increased by 73.4%, 185.9%, and 42.3%, respectively. Thermogravimetric analysis showed that GO-HMD played the role of the heterogeneous nucleation in the matrix and could change the crystal type of the polyamide. The T 50% and Td , max of nanocomposites were 14.3°C and 11.8°C higher than pure polyamide, respectively. The nanofiller GO-HMD contributes to the increase of the thermal diffusivity at low temperature.

Eugenol Polysiloxane-Polycarbonate/Graphene Nanocomposite: Enhanced in Thermostability and Barrier Property.

Graphene (GR) was used to blend with eugenol polysiloxane-polycarbonate (Si-PC) copolymer to prepare a Si-PC/GR nanocomposite via a solution blending method and the impact of graphene on the properties of Si-PC/GR nanocomposite was investigated. The morphology and structure of the Si-PC/GR nanocomposite were characterized. Combining morphology and property analysis, the result showed that when the graphene dispersed uniformly in the Si-PC matrix, the mechanical properties, thermostability and barrier property of Si-PC/GR nanocomposite were enhanced. Compared with Si-PC copolymer, the pyrolytic temperature of Si-PC/2.5%GR nanocomposite at 5% weight loss was 434.3 °C, which was 20.6 °C higher than Si-PC copolymer; and the oxygen barrier value of Si-PC/1.5%GR nanocomposite decreased to 160.2 cm3/m2 24 h 0.1 MPa, which was 53.2 less than pure Si-PC. The mechanical properties of Si-PC/GR nanocomposite were enhanced with an appropriate additive amount of graphene. The hydrophobicity also had been enhanced at the meantime.

Multi-role p-styrene sulfonate assisted electrochemical preparation of functionalized graphene nanosheets for improving fire safety and mechanical property of polystyrene composites

Polystyrene sulfonate functionalized graphene nanosheets (PSS@GNS) with high quality (ID/IG = 0.17) were fabricated through electrochemical exfoliation of bulk graphite followed by simple free radical polymerization in water solution, which is a promising strategy for mass production of polymer functionalized graphene. P-styrene sulfonate anions were used to intercalate into the bulk graphite under voltage and also as monomers of the macromolecule modification agents for the exfoliated graphene nanosheets. Besides, benzene rings and carbon double bonds are considered to be able to capture hydroxyl free radicals which produce defects on graphene sheets during electrochemical exfoliation process, thus improve the quality of the exfoliated graphene nanosheets. Then the graphene nanosheets were incorporated into polystyrene (PS) through a solution blending method to reduce the fire hazards and improve mechanical properties of PS resin. According to the results of cone calorimeter, the introduction of functionalized graphene nanosheets into PS reduces heat release rate (decreased by 40%), total heat release (decreased by 35%) and increases the amount of char residues. The flame retardant improvement is attributed to the barrier effect of well-dispersed graphene nanosheets, limiting the mass transfer of the volatile compounds and forming char layers which blocked polymers from heat and oxygen. Meanwhile, the introduction of PSS@GNS into PS also contributed to increase its strength and elongation rate thanks to the pristine properties of graphene nanosheets and their interfacial interaction with the PS matrix.