Morphological, optical, and barrier properties of PP/MMT nanocomposites

In this work, nanocomposites of polypropylene (PP) and organically modified montmorillonite (MMT) were evaluated concerning optical, mechanical, and barrier properties. The nanocomposites were prepared by melt compounding using a twin-screw extruder. The PP/MMT films were evaluated by measurements of oxygen and water vapor permeability, and to verify its efficiency as a barrier to ultraviolet radiation (by UV–Vis spectroscopy). MMT has demonstrated a high ability to improve the gas barrier properties of the PP. Furthermore, MMT showed optical efficiency acting as a UV absorber, and presented higher absorptions at wavelengths between 215 and 254 nm. These results suggest that these nanocomposite materials have great potential for applications such as films with superior properties for food packing.     

Flammable,thermal, and mechanical properties of intumescent flame retardant PP/LDH nanocomposites with different divalent cations

The flammable, thermal, and mechanical properties of intumescent flame retardant (IFR) polypropylene/layered double hydroxide (PP/IFR/LDH) nanocomposites with the LDHs of different divalent cations and IFR system of ammonium polyphosphate/pentaerythritol (APP/PER) have been studied by X-ray diffraction (XRD), cone calorimeter test (CCT), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), limiting oxygen index (LOI), UL-94 test, and mechanical measurements. The XRD results show that the exfoliated PP/IFR/LDH nanocomposites possess the nanoscaled dispersion characteristic. The data from the CCT tests show the synergistic effect of LDHs with IFR can decrease considerably the HRR, MLR, and EHC values of the PP/IFR/LDH nanocomposites, in which the pk-HRR, pk-MLR, and pk-EHC values of the PP/IFR/ZnAl-LDH sample decrease to 318 kW/m², 0.081 g/m² s, 61.8 MJ/kg from the corresponding values 506 kW/m², 0.115 g/m² s, 71.8 MJ/kg of the PP/IFR sample. The LOI and UL-94 data further support the evidence that the flame retardant synergistic effects of LDHs with IFR increase the LOI values and UL-94 rating, especially for the LDHs with the transition ions (Zn, Cu) the LOI values can reach 33% and the UL-94 pass the V-0 rating. The TGA results demonstrate the LDHs can greatly improve the thermal stabilities of PP/IFR/LDH nanocomposites by increasing the thermo-oxidation decomposition temperature and charred residues. The morphological structures observed by SEM have demonstrated the LDHs can promote formation of compact charred layers. The data from the mechanical tests show the tensile strength and elongation at break of the PP/IFR/LDH samples are basically unchanged compared with the PP/IFR sample. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Morphology and thermal stabilization mechanism of LLDPE/MMT and LLDPE/LDH nanocomposites

The morphology and thermal stabilization mechanism of polymeric nanocomposites prepared by solution intercalation of linear low density polyethylene (LLDPE) with montmorillonite (MMT), MgAl layered double hydroxide (LDH), and ZnAl LDH have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). Both LLDPE/MMT and LLDPE/MgAl LDH nanocomposites exhibit mixed intercalated-exfoliated structures, whereas the LLDPE/ZnAl LDH nanocomposites exhibit completely exfoliated structures because the ZnAl LDH layers can be easily broken during the refluxing process. All nanocomposites show significantly enhanced thermal stability compared with virgin LLDPE due to the increases of the effective activation energy (E_α) during degradation process. However, LDHs nanocomposites show much higher thermal degradation temperatures than MMT nanocomposites with the same filler content because they have much higher E_α than MMT nanocomposites at the early degradation stage. The data of real time FTIR spectroscopy and morphological evolution reveal a catalytic dehydrogenation effect presents in MMT nanocomposites, which may decrease the E_α of degradation and thermal stability of MMT nanocomposites.     

Synergistic effects of exfoliated LDH with some halogen‐free flame retardants in LDPE/EVA/HFMH/LDH nanocomposites

The synergistic effects of exfoliated layered double hydroxides (LDH) with some halogen‐free flame retardant (HFFR) additives, such as hyperfine magnesium hydroxide (HFMH), microencapsulated red phosphorus (MRP), and expandable graphite (EG), in the low‐density polyethylene/ethylene vinyl acetate copolymer/LDH (LDPE/EVA/LDH) nanocomposites have been studied by X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermal analysis (TGA and DTG), mechanical properties, limiting oxygen index (LOI), and UL‐94 tests. The XRD results show that EVA as an excellent compatilizer can promote the exfoliation of LDH and homogeneous dispersion of HFMH in the LDPE/EVA/HFMH/LDH nanocomposites prepared by melt‐intercalation method. The TEM images demonstrate that the exfoliated LDH layers can act as synergistic compatilizer and dispersant to make the HFMH particles dispersed homogeneously in the LDPE matrix. The results from the mechanical, LOI, and UL‐94 tests show that the exfoliated LDH layers can also act as the nano‐enhanced and flame retardant synergistic agents and thus increase the tensile strength, LOI values, and UL‐94 rating of the nanocomposites. The morphological structures of charred residues observed by SEM give the positive evidence that the compact charred layers formed from the LDPE/EVA/HFMH/LDH nanocomposites with the exfoliated LDH layers play an important role in the enhancement of flame retardant and mechanical properties. The TGA and DTG data show that the exfoliated LDH layers as excellent flame retardant synergist of MRP or EG can apparently increase the thermal degradation temperature and the charred residues after burning. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Matrix tacticity controlled tuning of microstructure,constitutive behavior and rheological percolation effect of melt‐mixed amino‐functionalized MWCNT/PP nanocomposites

Amino‐functionalized multi walled nanotube (MWCNT‐NH₂) filled isotactic PP and isotactic‐syndiotactic (70:30) mixed PP based melt‐mixed nanocomposites have been comparatively evaluated with regard to morphological, rheological and thermo‐mechanical properties. The ratio of mean free space lengths (L_f) to infiltrated mean free space lengths (L_inf) between nanotubes in isotactic‐syndiotactic (70:30) blended matrix based nanocomposites increased relatively indicating a dispersed‐morphology. The rheological percolation threshold increased up to a higher extent of MWCNT‐NH₂ loading (from ø_c ～ 2.3 × 10^?4 in isotactic to ø_c ～ 11 × 10^?4 in iso‐syndio blend) accompanied with the formation of a mechanically responsive network structure. van‐GurpPalmen plot showed a transition in the rheological response as a consequence of network morphology getting shifted to higher concentration of MWCNT‐NH₂ in the isotactic‐syndiotactic mixed PP based nanocomposites than in the isotactic based one. Constitutive modeling of complex viscosity response of the nanocomposites led to functional correlation between the percolation and relaxation dynamics of polymer chains. POLYM. ENG. SCI., 58:1115–1126, 2018. © 2017 Society of Plastics Engineers     

Structure,crystallization behavior,and thermal stability of PP/MCM‐41 nanocomposite

The structure, crystallization, and thermal stability of polypropylene containing nanosized MCM‐41 particle, whose pore channels were filled with polystyrene inside the pore channels with the aid of supercritical CO₂, were investigated by X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analyses, respectively. The results of differential scanning calorimetry showed that the incorporation of MCM‐41 (without template) increased the melting temperature and the crystallization temperature by approximately 7 and 1.8°C, respectively. Although the incorporation of MCM‐41 (with template) and MCM‐41‐S‐PS decreased the melting temperature, the crystallization temperature and the crystallization rate increased. The result of crystallization kinetics showed dramatic increase in crystallization rate and decrease in t_1/2 and t_f for PP/MCM‐41 (without template) nanocomposite, whereas decrease in crystallization rate and increase in t_1/2 and t_f for PP/MCM‐41 (with template) and PP/MCM‐41‐S‐PS nanocomposites. The thermal results indicated that the thermal stability of the composite was enhanced by addition of all nanoparticles. At the 95% weight loss, adding 2.5 wt% nanomaterial, the decomposition temperature of PP/MCM‐41‐S‐PS was 50.71°C higher than that of PP, 13.98°C higher than that of PP/MCM‐41 (without template), and 0.39°C higher than that of PP/MCM‐41 (with template). POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

PP/黏土纳米复合材料的结构与性能

采用熔体插层法制备聚丙烯（PP）/有机黏土（OMMT）纳米复合材料。XRD和TEM的测试结果表明,采用熔体插层法制备的PP/OMMT复合材料是剥离型纳米复合材料。力学性能实验结果表明,相容剂的加入提高了PP与OMMT之间的相互作用,使其各项力学性能都得到了提高;PP/OMMT纳米复合材料的各项力学性能在有机黏土含量较小的情况下,就可以有较大幅度的提高;与纯PP相比,相容剂含量为10 phr、有机黏土用量为1 phr的聚丙烯基纳米复合材料具有最好的各项力学性能。     

Preparation and properties of melt‐mixed metallocene polyethylene/silica nanocomposites

Metallocene polyethylene (mPE)/silica nanocomposites were prepared via melt mixing. Two types of commercial fumed nanosilica, bare silica (A200) and organic modified silica (R974), were incorporated to improve the mechanical properties of the nanocomposites. Transmission electron microscopy, atomic force microscopy, and scanning electron microscopy revealed that the modified silica was dispersed slightly better within the mPE matrix. No distinct effects on the thermal behaviors of the fast‐crystallizing mPE matrix were observed with variations in both the silica dosages and types. Thermal stability was enhanced through the addition of nanosilica, with or without surface treatment. The surface‐modified silica system showed slightly higher tensile strength and Young's modulus compared with the bare silica system, as evidenced by a rheological study using a Cole‐Cole plot to assess enhanced polymer matrix‐dispersed silica interactions, especially for high dosages of organic modified silica. A limited increment in the dynamic storage modulus for modified silica cases, completely opposite of that observed for bare silica cases, was due to the low‐aspect ratio of smaller agglomerates from highly dispersed organic modified silica within the mPE matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.     

Preparation of exfoliated high‐impact polystyrene/MMT nanocomposites via in situ polymerization under controlling viscosity of the reaction medium

Exfoliated high‐impact polystyrene (HIPS)/montmorillonite (MMT) nanocomposites were prepared via in situ polymerization of styrene in the presence of polybutadiene, using an intercalated cationic radical initiator‐MMT hybrid (organoclay). In the solution polymerization in toluene, the silicate layers of the clay were well exfoliated, due to the low extra‐gallery viscosity that can facilitate the diffusion of styrene monomers into the clay layers during the polymerization. The exfoliated HIPS/MMT nanocomposites were also successfully prepared by controlling the viscosity of the reaction medium with prolong swelling of the organoclay in styrene, prior to bulk polymerization. The HIPS/MMT nanocomposites, obtained from bulk polymerization, exhibited a significant improvement in thermal stability, compared to those obtained from solution polymerization as well as the pure polymer counterparts. POLYM. COMPOS., 2008. © 2007 Society of Plastics Engineers     

Reversed micelle Synthesis of Ag/polyaniline nanocomposites via an in situ ultraviolet photo‐redox mechanism

Silver/polyaniline nanocomposites were synthesized in reversed micellar solution, and the reaction was performed via in situ reduction of silver nitrate in aniline by photolysis. The nanocomposites were characterized by ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, thermo‐gravimetric analysis, differential scanning calorimetric analysis, and electrochemical methods. The results showed that the Ag/polyaniline nanocomposites are composed of nano‐sized particles of 15–30 nm that contain Ag domains of 10–15 nm. The electrical conductivity of an Ag/polyaniline pellet is 95.89 S cm⁻¹, whereas a polyaniline pellet is found to be 3.1 × 10⁻² S cm⁻¹. Ag/polyaniline composites also have a higher degradation temperature and specific capacitance, when compared with pure polyaniline. Potentiodynamic polarization showed the anodic shifting of the zero current potential and a lower exchange current density for the Ag/polyaniline composite. Compared with polyaniline, the Ag/polyaniline nanocomposite is a promising candidate for coatings with improved anticorrosion performance. POLYM. COMPOS.,, 2012. © 2012 Society of Plastics Engineers     

Polypropylene nanocomposites with oxo‐degradable pro‐oxidant: Mechanical,thermal, rheological,and photo‐degradation performance

The objective of the study was to generate degradable polypropylene nanocomposites by incorporation of pro‐oxidant and different fillers like silica, silicate, and thermally reduced graphene. Graphene‐based composites exhibited higher crystallinity attributed to better dispersion and high aspect ratio platelets. Graphene composites with 2.5% additive content significantly enhanced the peak degradation temperature to 464°C as compared to 448°C for pure polymer. The processing conditions used for the nanocomposite generation were optimum as a uniform distribution of filler particles (or platelets) was observed in the PP matrix. The tensile modulus of the graphene composite with 2.5% additive content was 80% higher than pure PP, as compared to 60 and 30% for silicate and silica composites, respectively. Similarly, the storage modulus of the graphene nanocomposite with 1% additive content had 30% increment at 40°C as compared to pure PP. PP‐additive blends as well as PP nanocomposites with silica and silicate were observed to attain 100% degree of embrittlement within 6 months of UV exposure at 30°C. Graphene composites, though, had delayed photo‐degradation due to UV absorption by the platelets and high aspect ratio platelets acting as oxygen barrier for PP matrix, but the pro‐oxidant was successful in attaining controlled degradation. POLYM. ENG. SCI., 56:1229–1239, 2016. © 2016 Society of Plastics Engineers     

Linear and nonlinear melt‐state viscoelastic properties of polypropylene/organoclay nanocomposites

Rheological behavior of polypropylene (PP)/organoclay nanocomposites varying in compatibilizer (PP‐g‐MA) and organoclay concentration was investigated. The samples were prepared by melt intercalation method in an internal mixer. The wide angle X‐ray diffraction patterns and results of rheological measurements showed that the compatibilizer had strong influence in increasing the interlayer spacing. The observed low frequency liquid‐like to solid‐like transition and apparent yield stress in simple shear flows, along with convergence of transient shear stress to nonzero values in stress relaxation after the cessation of flow experiments, were found to be consistent with formation of a physical network in quiescent conditions which could be easily ruptured with applying low shear rates. The values of stress overshoot strain in flow reversal experiments were independent of shear rate, organoclay, and compatibilizer content. From the results of frequency sweep experiments in different nonlinear strain amplitudes it was shown that extended Cox‐Merz analogy was valid in nonlinear dynamic deformations while the shear viscosity showed positive deviation from this analogy with higher deviations at lower shear rates. Results of storage modulus recovery and flow reversal experiments at different shear rates suggested that network structure is reformed with a much slower rate compared to the rotational relaxation of organoclay platelets. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Synthesis,characterization, and thermal aging behavior of HCl‐doped polyaniline/TRGO nanocomposites

In this article polyaniline (PANI) nanocomposites containing thermally reduced graphene oxide (TRGO) were synthesized and characterized before and after thermal aging. The nanocomposites were prepared through in situ oxidative polymerization of aniline in the presence of TRGO nanoplatelets. FTIR and Raman spectroscopies, XRD, FESEM, and electrical conductivity measurements were used to characterize synthesized materials. PANI/TRGO nanocomposites showed considerably higher electrical conductivity when compared to pure PANI, which was associated with the higher electrical conductivity of TRGO and increased crystallinity of PANI in the presence of TRGO. Pure PANI and PANI/TRGO nanocomposites were thermally aged at 70, 80, 90, and 100 °C. The results showed that the characteristic time of thermal aging process is higher for PANI/TRGO nanocomposites and increases with TRGO loading, which indicates better stability of conductivity during thermal aging process. On the other hand, the characteristic time of thermal aging reduced with aging temperature and a fast decrease was observed from 80 to 90 °C. Improved resistance over thermal aging can be attributed to the barrier effect of TRGO nanoplatelets to the dopant molecules, which retards conductivity degradation in the thermal aging process. Furthermore, TRGO increases PANI crystallinity and it can also prevent crystallinity reduction during thermal aging process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44635.     

Natural rubber/cis‐1,4‐polybutadiene nanocomposites: Vulcanization behavior,mechanical properties,and thermal stability

Natural rubber/cis‐1,4‐polybutadiene (NR/BR) blends with two types of layered nanofillers, montmorillonite (MMT) and layered double hydroxide (LDH), both in pristine and organically modified forms are produced and investigated. Faster curing is found for all the NR/BR blends, except for the one containing the unmodified MMT. This effect can be attributed to the groups placed in the interlayer regions of the clays; more precisely to ammonium groups for the organo‐MMTs and to ? OH groups for LDHs. Mechanical properties and thermal stability of rubber compounds are investigated. It has been demonstrated that the performance of the final nanocomposite is significantly affected by the kind of clay. Particularly, the organo‐MMTs provoke an improvement of the mechanical properties and increase the thermal stability of about 4–5° C in respect to the pure NR/BR matrix. On the contrary, the poor compatibility of unmodified MMT and of LDH clays with the rubber blend is evident and no enhancement on the composite performance has been observed. POLYM. ENG. SCI., 2013. © Society of Plastics Engineers     

Crystallization behavior of syndiotactic polystyrene nanocomposites for melt‐ and cold‐crystallizations

Analyses of the effects of montmorillonite (clay) on the crystallinity and crystallization behavior of syndiotactic polystyrene (s‐PS) were investigated by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The dispersibility of the clay in s‐PS nanocomposites was studied by X‐ray and transmission electron microscopy (TEM). The clay was dispersed into the s‐PS matrix by melt blending on a scale of 1–2 nm or few tenths–100 nm, depending on the surfactant treatment. On adding clay, the crystallization behavior of the s‐PS tends to convert into the β‐crystal from the α‐crystal after being cold‐crystallized because the clay plays a vital role in facilitating the formation of the thermodynamically favored β‐form crystal when the s‐PS is cold‐ or melt‐crystallized. This phenomenon leads to a change in a conventional mechanism of molecular packing for the s‐PS. Evidently, the clay significantly affects the crystallinity and crystallization behavior of the s‐PS. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2492–2501, 2002     

Ethylene‐VInyl acetate/LDH nanocomposites with enhanced thermal stability,flame retardancy,and rheological property

In this contribution, ethylene‐vinyl acetate (EVA)/Zn₂Al‐X layered double hydroxides (LDHs) nanocomposites containing different interlayer anions including CO₃^2–, NO₃^–, Cl^–, SO₄^2– were synthesized using solvent mixing method for the first time. The influence of the interlayer anions of LDHs on the thermal stability, flame retardancy, and rheological behaviors of these nanocomposites were investigated in detail. The results indicated that both the thermal stability and the flame retardancy could be significantly enhanced, and the extent was highly dependent on the type of interlayer anions that were intercalated in LDHs. The influence of different anions on the storage and loss moduli followed the order of SO₄^2– > NO₃^– > CO₃^2– > Cl^–, suggesting that the interlayer anions significantly affect the rheological behaviors of the nanocomposites as well. This work is of great importance to both the academic and industrial fields since it demonstrated that a proper selection of the interlayer anions and an optimization of the chemical composition are crucial for the practical application of such nanocomposites. POLYM. COMPOS., 37:3449–3459, 2016. © 2015 Society of Plastics Engineers     

Influence of reactive compatibilization on the structure and properties of PP/LDH nanocomposites

Polypropylene (PP)/layered double hydroxide (LDH) nanocomposites were prepared by the direct melt intercalation method using maleic anhydride grafted polypropylene (PP‐g‐MAH) as a reactive compatibilizer. The compatibilization effects provided by PP‐g‐MAH in different weight fractions and their influence on the structure and properties of the final nanocomposites were investigated. The interactions and structural morphology of the nanocomposites were examined by Fourier transform infrared spectroscopy, X‐ray diffraction and transmission electron microscopy. Thermal, mechanical and rheological properties of these nanocomposites were investigated as a function of compatibilizer concentration. The detailed morphological and X‐ray diffraction results revealed that the degree of LDH dispersion increases as the amount of PP‐g‐MAH increases. Study of the linear viscoelastic properties showed that the storage modulus G′ is very sensitive to the microstructure of the nanocomposite. The thermal properties of the nanocomposites were significantly influenced by the weight fraction of PP‐g‐MAH due to the shielding and nucleating effect of exfoliated layers. Both the tensile strength and modulus showed substantial improvements with increasing PP‐g‐MAH content, while the elongation at break substantially decreased, although the presence of PP‐g‐MAH somewhat improves these values. The overall results showed that 10 wt% of compatibilizer is optimum to achieve nanocomposites with better performance. Copyright © 2011 Society of Chemical Industry     

Preparation and properties of melt‐blended polylactic acid/polyethylene glycol‐modified silica nanocomposites

One commercial type of fumed silica modified with methoxy polyethylene glycol (mPEG) plasticizer was incorporated into polylactic acid (PLA) biobased polymer to improve its performance. The modification on silica was confirmed through Fourier transform infrared spectra, nuclear magnetic resonance, and TGA assessments. The grafting percentage of mPEG onto silica was about 19.8 wt %. Transmission electron microscope revealed a similar degree of dispersion for control silica and modified silica‐filled PLA nanocomposites. Not much difference in the glass transition temperatures at various silica contents was found for PLA/control silica systems from the differential scanning calorimetry measurement, but the glass transition temperature of PLA/modified silica nanocomposite at 10 phr of modified silica showed up to 11°C decrement. It was suggested that the mPEG plasticizer efficiently plasticized the PLA matrix through the enhanced segmental mobility of PLA chains. Young's modulus of PLA was about 2133 ± 53 MPa, and the value for the nanocomposite increased to 2547 ± 54 MPa at 10 of phr control silica mainly due to the reinforcing effect from nanoparticles. For modified silica, Young's modulus decreased at various silica contents. The elongation at break for modified silica‐filled cases was higher than that of control silica‐filled cases. These results were attributed to the plasticizing effect of surface modifier. Optical transmittance for pristine PLA was generally in a similar order as PLA/control silica and modified silica cases at various silica contents. The results agreed with the morphology observation as well. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of clay exfoliation and organic modification on morphological,dynamic mechanical,and thermal behavior of melt‐compounded polyamide‐6 nanocomposites

Polyamide‐6/clay nanocomposites were prepared employing melt bending or compounding technique followed by injection molding using different organically modified clays. X‐ray diffraction and transmission electron microscopy were used to determine the molecular dispersion of the modified clays within the matrix polymer. Mechanical tests revealed an increase in tensile and flexural properties of the matrix polymer with the increase in clay loading from 0 to 5%. C30B/polyamide‐6 nanocomposites exhibited optimum mechanical performance at 5% clay loading. Storage modulus of polyamide‐6 also increased in the nanocomposites, indicating an increase in the stiffness of the matrix polymer with the addition of nanoclays. Furthermore, water absorption studies confirmed comparatively lesser tendency of water uptake in these nanocomposites. HDT of the virgin matrix increased substantially with the addition of organically modified clays. DSC measurements revealed both γ and α transitions in the matrix polymer as well as in the nanocomposites. The crystallization temperature (T_c) exhibited an increase in case of C30B/polyamide‐6 nanocomposites. Thermal stability of virgin polyamide‐6 and the nanocomposites has been investigated employing thermogravimetric analysis. POLYM. COMPOS., 28:153–162, 2007. © 2007 Society of Plastics Engineers     

Rheological behavior ‐ Electrical and thermal properties of polypyrrole/graphene oxide nanocomposites

Polypyrrole/graphene oxide (Ppy/GO) nanocomposites were synthesized via in situ polymerization of pyrrole in the presence of GO at various proportions (1–5%). They were characterized to determine their electrical, thermal, and rheological properties by various techniques. The aim of this study was to determine the rheological behavior of Ppy/GO nanocomposite at different mass ratios (100 : 1, 100 : 2, 100 : 3, 100 : 4, and 100 : 5%) and temperature (25–180°C) using a rotational mode in cone‐plate method. The shear stress (τ Pa) and viscosity (η Pa s) values of the nanocomposites increased with the increase in GO mass ratio added to Ppy, which was accompanied by an increased flexibility of the nanocomposites due to the higher aspect ratio of the GO sheet. Hence, it is suggested that the GO sheets are effective for the reinforcement of Ppy thereby significantly improvising its thermal stability, electrical conductivity, and rheological properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40642.