Effects of silica particle size on the structure and properties of polypropylene/silica composites foams

In this study, we prepared organically modified silica materials with various particle sizes, in the ranges of micrometer and nanometer, and their polypropylene (PP) composites. The PP micro/nanocomposites were then molded through conventional and microcellular injection molding processes. The effects of silica particle sizes on the structure, mechanical and rheological properties were investigated. The results showed that PP/silica nanocomposites provide better tensile strength than that of foamed nanocomposites. The addition of silica also increased the tensile strength of the nanocomposites, but decreased the tensile strength of microcomposites. Therefore, the tensile strength of PP/silica nanocomposites is better than that of PP/silica microcomposites. The silica particles helped the nanocomposites to develop small cells in the foaming process. Rheological results indicated an increase in the viscosity with the addition of nano silica and micro silica to PP. The viscosity increase for the silica nanocomposites was found greater than that of microcomposites at the same filler content.     

Poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride)/silica nanocomposites derived from in situ suspension polymerization

Poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride) (PVVM)/silica nanocomposites were prepared by the suspension radical copolymerization of the monomers in the presence of fumed silica premodified with γ‐methylacryloxypropl trimethoxy siliane. Morphological observation showed that the silica particles of nanometer scale were well dispersed in the copolymer matrix of the nanocomposites films, whereas silica particles tended to agglomerate in the composites films prepared by the solution blending of PVVM with silica. The experimental results show that the thermal stability, glass‐transition temperature, tensile strength, and Young's modulus were significantly enhanced by the incorporation of silica nanoparticles. The enhancement of properties was related to the better dispersion of silica particles in polymer matrix and the interaction between the polymer chains and the surfaces of the silica particles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Properties of bulk-polymerized thermoplastic polyurethane nanocomposites

The thermal, rheological, and mechanical properties of bulk-polymerized thermoplastic polyurethane nanocomposites of reactive and non-reactive layered silicate clay were characterized as a function of the state of dispersion of particles. True exfoliated nanocomposites were produced by mixing reactive clay particles with polymer chains carrying residual isocyanate groups. On the other hand, non-reactive clay particles yielded only intercalated composites. Most significant improvement in mechanical properties were obtained when clay particles were fully exfoliated, e.g. 110% increase in tensile modulus, 170% increase in tensile strength, 110% increase in tear strength, 120% increase in fracture toughness, and 40% increase in abrasion resistance over pristine polyurethane with 5 wt% clay. In addition, the terminal dynamic rheological data showed strong dependence on the clay content, indicating substantial hindrance to chain relaxation by tethering clay particles. The peak location and the area under the peak of hydrogen-bonded carbonyl showed two distinct zones of temperature dependence, which indicate additional hydrogen bonding between polymer chains and organic modifier of reactive clays.     

Polyamide 6/silica nanocomposites prepared by in situ polymerization

A polyamide 6 (PA 6)/silica nanocomposite was obtained through a novel method, in situ polymerization, by first suspending silica particles in ϵ-caproamide under stirring and then polymerizing this mixture at high temperature under a nitrogen atmosphere. The silicas were premodified with aminobutyric acid prior to the polymerization. The effects of the addition of unmodified and modified silicas on the dispersion, interfacial adhesion, isothermal crystallization, and mechanical properties of PA 6 nanocomposites were investigated by using scanning electron microscopy, dynamic mechanical analysis, differential scanning calorimetry, and mechanical tests, respectively. The results show that the silicas dispersed homogeneously in the PA 6 matrix. The addition of silicas increases the glass transition temperature and crystallization rate of PA 6. The mechanical properties such as impact strength, tensile strength, and elongation at break of the PA 6/modified silica nanocomposites showed a tendency to increase and decrease with increase of the silica content and have maximum values at 5% silica content, whereas those of the PA 6/unmodified silica system decreased gradually. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 355–361, 1998     

Mechanical properties of low nano‐silica filled high density polyethylene composites

Modification of nanoparticles through graft polymerization is able to change the chemical nature of the particles' surfaces and provides an effective means for the preparation of nano‐fillers specified for composites manufacturing. The present work focuses on the mechanical role of grafted nano‐SiO₂ particles in high density polyethylene composites prepared by melt compounding. The experimental results show that at a content of 0.75 vol%, the modified nano‐silica results in a rise in tensile stiffness, tensile strength and impact strength of the composites. The grafted nanoparticles can improve the mechanical performance of the matrix polymer more effectively than the untreated version. In addition, a further enhancement of the composites stiffness and strength can be achieved by crosslinking the concentrated masterbatches, which has not yet been revealed in the authors' previous works on grafted nano‐SiO₂ particles/polypropylene composites. It is thus revealed that the introduction of the grafting polymers onto the nanoparticles increases the tailorability of the composites.     

Effect of compatibilizer on the dispersion of untreated silica in a polypropylene matrix

BACKGROUND: A new processing method for polypropylene–untreated precipitated silica (PP/SiO₂) composites based on the incorporation of a second polymer phase of polyamide 6 (PA6) is presented and compared with a more classic one making use of compatibilizers: glycerol monostearate (GMS), ethylene acrylic acid ionomer (IAAZE) and maleic anhydride grafted polypropylene (MA‐graft‐PP). The effects of processing methods and conditions on the microstructure and properties of PP/SiO₂ composites prepared by melt compounding are investigated with a view to reduce the size of aggregates of silica from the micrometre to the nanometre scale and to improve the link between filler and matrix. RESULTS: On the one hand, the presence of GMS and IAAZE compatibilizers significantly improves the dispersion of the silica particles. On the other hand, when using a PA6 second phase, the SiO₂ particles are dispersed in PA6 nodules. Within these nodules, SiO₂ appears dispersed at the nanoscale but with larger particles (‘aggregates’) of about 200 nm. Significant improvements in tensile strength and modulus are obtained using MA‐graft‐PP compatibilizer. An increase in impact strength is observed in the case of GMS compatibilizer. Thermal parameters indicate also that silica plays the role of nucleation agent for PP matrix. All improvements (tensile strength, modulus and impact strength) increase with the addition of compatibilized PA6 second phase. CONCLUSION: By the incorporation of masterbatch of silica in PA6 as a second polymer polar phase, a successful new production method for PP/SiO₂ nanocomposites has been developed. Interestingly, this method does not require any (expensive) pre‐treatment of the silica. Copyright © 2007 Society of Chemical Industry     

Polymer nanocomposite powders and melt spun fibers filled with silica nanoparticles

Nanocomposite powders from polypropylene filled with surface modified and unmodified fumed silica have been prepared from polymer solution to achieve improved mixing and have been forwarded to fiber melt spinning. The surface of the fumed silica was modified with dodecyl alkoxy silanes. Crystallization velocity and viscosity of the PP nanocomposites thereof were determined to ensure good melt spinning processing conditions for all composite compositions. Upon addition of untreated filler particles, a shear thinning and an increased crystallization velocity of the polymer melt was found, while only minor changes were detected in the presence of surface modified fumed silica particles. The composites and the polymer fibers made from these powder composites by melt spinning were mainly characterized by optical microscopy (OM), scanning electron microscopy (SEM), mechanical measurements, differential scanning calorimetry (DSC), and solid‐state NMR. The unmodified fumed silica was found to have a strong influence on the mechanical fiber properties, while the surface modified silica only a small one. Fibers were additionally characterized with respect to the uniformity, the PP crystallinity, moisture absorption, and the water contact angle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 218–227, 2007     

The effect of the interface structure of different surface‐modified nano‐SiO2 on the mechanical properties of nylon 66 composites

The nylon 66‐based nanocomposites containing two different surface‐modified and unmodified SiO₂ nanoparticles were prepared by melt compounding. The interface structure formed in different composite system and their influences on material mechanical properties were investigated. The results indicated that the interfacial interactions differed between composite systems. The strong interfacial adhesion helped to increase tensile strength and elastic modulus of composites; whereas, the presence of modification layer in silica surface could enhance the toughness of composites, but the improvement of final material toughness was also correlated with the density of the adhered nylon 66 chains around silica nanoparticles. In addition, the results also indicated that the addition of surface‐modified silica nanoparticles has a distinct influence on the nonisothermal crystallization behavior of the nylon 66 matrix when compared with the unmodified silica nanoparticle. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of reaction parameters on the structure and properties of acrylic rubber/silica hybrid nanocomposites prepared by sol‐gel technique

The effects of a few reaction parameters, namely, type of solvents, tetraethoxysilane (TEOS)‐to‐water mole ratio, and temperature of gelation at constant concentration of TEOS (45 wt %) and pH of 1.5 were investigated for acrylic rubber/silica hybrid nanocomposites prepared by sol‐gel technique. Infrared spectroscopic studies indicated the maximum silica generation within the system when tetrahydrofuran was used as the solvent for the sol‐gel reaction. The distribution of the silica particles (average dimension 100 nm) forming a network type of structure within the composite was confirmed by scanning electron microscopic studies (SEM). The other solvents studied here produced a lower amount of silica because of either high polarity of the solvents (methyl ethyl ketone and dimethyl formamide) or their limited miscibility with water (for ethyl acetate). An increase in the proportion of water caused silica agglomeration. Energy dispersive X‐ray analysis (EDAX) silicon mapping also demonstrated the existence of agglomerated silica structures at high TEOS‐to‐water mole ratio (>2). Higher temperature for gelation of the composites caused the aggregation of silica particles. The uncured composites containing nanolevel (<90 nm) dispersion of silica particles demonstrated slightly higher storage modulus, lower value of tan δ_max, and higher glass transition temperature compared to the composites with silica particles of a larger dimension (>2 μm). Improvement in tensile strength and modulus was observed in the uncrosslinked as well as in the crosslinked state (cured by a mixed crosslinking system of hexamethylenediamine carbamate and ammonium benzoate). However, the extent of improvement in strength and modulus for the nanocomposites was higher (247 and 57%, respectively) compared to the microcomposite (150 and 27%, respectively) in the cured state. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1418–1429, 2005     

Effects of silica aerogel particle sizes on the thermal–mechanical properties of silica aerogel – unsaturated polyester composites

Silica aerogels with a surface area as high as 773?m²?g^?1 and a density of 0.077?g?cm^?3 were produced from rice husk via sol–gel process and ambient pressure drying. A particulate composite material was prepared by adding silica aerogel particles of three different particle sizes (powder, granules and bead) to unsaturated polyester resin with a fixed volume fraction of 30%. Thermogravimetric and thermal conductivity studies revealed that silica aerogel composites were having higher thermal stability and thermal insulation than the neat resin. It was suggested that the preservation of aerogel pores from resin intrusion is important for better thermal properties. Larger silica aerogel particles have more porous area (unwetted region) which results in a lower degradation rate and lower thermal conductivity of the base polymer. However, the addition of silica aerogel into resin has reduced the tensile modulus of the polymer matrix where smaller particle size displayed higher toughness than those with bigger particle size.     

Carbon/carbon nanocomposites derived from phenolic resin-silica hybrid ceramers: microstructure, physical and morphological properties

Phenolic resin-silica hybrid ceramers were prepared through the sol-gel method. The hybrid ceramers with various inorganic contents were used as matrix precursors to fabricate silica containing carbon/carbon (C/C) composites. The effect of the organic-inorganic mixing ratio on the change of density and porosity was studied. The flexural strength and modulus of the C/C composites was also investigated. Results show that the density of the C/C composites increases with silica content. However, at higher silica content, the density of the composites does not change before and after carbonization. Silica increases the stiffness of the fabricated C/C composites from 2.4×10⁴ to 3.0×10⁴ MPa. However, it does not affect the flexural strength. XRD and Raman spectra studies show that the incorporation of inorganic silica into the phenolic resin influences the growth of ordered carbon structures. From SEM morphological observations, it was concluded that the silica particles are dispersed uniformly on the surfaces of the specimens with some particles located at the pores due to the decomposition of the polymer matrix.     

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.     

Effect of microstructure of acrylic copolymer/terpolymer on the properties of silica based nanocomposites prepared by sol-gel technique

Acrylic copolymers/terpolymers with different comonomer contents were prepared by solution polymerization. Copolymers/terpolymers-silica hybrid composites were synthesized by acid catalyzed sol-gel technique using tetraethoxysilane (TEOS) as silica precursor. Microstructure of the copolymers and the terpolymers was analyzed by C¹³ nuclear magnetic resonance and Fourier transform infrared (FTIR) spectroscopy. The hybrid composites were characterized by scanning electron microscopy (SEM), FTIR, thermogravimetry, dynamic mechanical thermal analysis (DMTA) and their mechanical properties. The results showed that an increase in hydrophilicity of the polymer matrix and the ratio of ethyl to butyl acrylate, and incorporation of acrylic acid as termonomer helped in finer dispersion of silica and prevented macrophase separation. There was no evidence of chemical interaction between the polymer and the dispersed silica phase. Dynamic mechanical thermal analysis indicated mechanical reinforcement within the hybrid composites. As a result, these composites demonstrated superior tensile strength and tensile modulus with increasing proportion of TEOS up to a certain level. At a particular TEOS concentration, the tensile properties improved with increasing hydrophilicity of the polymer matrix and acrylic acid modification. The mechanism for improvement in mechanical and dynamic mechanical properties of the hybrids was discussed.     

Clay‐Assisted dispersion of carbon black in thermoplastic nanocomposites

The poor dispersion of carbon black (CB) in thermoplastic polymers has provided a space for improving the various properties of nanocomposites. In this study, nanoclay (NC) was introduced into CB/thermoplastic composites to improve the dispersion of CB and, finally, to improve the thermal or mechanical performance. We noticed that there was a simultaneous enhancement in the mechanical and thermal performances of the nanocomposites because of the combination of the NC and CB. The information obtained from the mechanical and thermal studies indicated that the properties were improved to an appreciable extent because of the plastic–plastic/CB/NC combination. The tensile strength of polycarbonate (PC) was observed to be enhanced by 9.4% only because of the addition of CB, although when poly(methyl methacrylate) (PMMA) was used as a matrix material along with PC, the tensile strength improved by 25%, although the tensile strength of PMMA is much lower than that of PC. This confirmed that the tensile properties of the polymer composites also depended on the plastic–plastic interaction phenomenon. Moreover, the tensile strengths of the different blended nanocomposites system increased by around 42.5% with the addition of NC. A significant improvement of 22% was achieved in the thermal stability of the PMMA composites with the addition of CB. However, the addition of NC provided further improvement in the thermal decomposition temperature by only 3.7%. This showed that the thermal stability of the polymer nanocomposites was slightly affected by the addition of NC. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41477.     

Synthesis of modified silica spheres used for the preparation of dual ultraviolet‐ and thermo‐cured epoxyacrylate/silica composites

To investigate the interfacial effect on properties of epoxyacrylate–silica composites, submicron‐sized silica spheres were synthesized by sol–gel reaction under a basic environment and their surfaces were endowed with vinyl functional groups by further modification with 3‐methacryloxypropyl trimethoxy silane. The pure silica (PS) and the modified silica (MPS) spheres were characterized by Fourier transform infrared, ²⁹Si‐ and ¹³C‐nuclear magnetic resonance (NMR), scanning electron microscope (SEM), and particle size analyzer. The silica spheres were then added to the presynthesized difunctional epoxyacrylate resin with one vinyl group and one epoxide group at each end, in addition to the photo‐ and thermo‐curing agents. After cure, thermal and mechanical properties of the obtained epoxyacrylate–silica composites were measured and compared. Tensile mechanical properties including initial modulus, ultimate tensile strength, and elongation at break, as well as the fracture energy of the epoxyacrylate–silica composite were all increased by increasing the content of silica spheres. Moreover, the composites filled with MPS had stronger interfacial strength between silica sphere and matrix than those with PS and thus exhibited an additional increase of tensile mechanical properties and fracture toughness. The increase of fracture toughness was owing to the crack deflection and particle–matrix debonding as evidenced by SEM pictures on the fracture surface. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Effects of silica nanoparticles on tribology performance of poly(Epoxy Resin‐Bismaleimide)‐based nanocomposites

Introduction of small nanoparticles into polymer matrix increases the mechanical, tribological, and thermal properties of nanocomposites. In this study, poly(epoxy resin‐bismaleimide‐diaminodiphenylmethane) (EP‐BMI‐DDM) copolymers filled with silica nanoparticles (SNPs) were successfully fabricated through in situ suspension polymerization. To enhance the interfacial adhesion of silica particles to the polymer matrix, the nanoparticles were organo‐modified by silane coupling agent. Results of tensile strength test revealed that increased toughness of the composites was attributed to the microcavitations induced by organo‐modified SNPs (OSNPs). Proper loadings of OSNPs can play a critical role in antifriction performance, with optimal friction coefficient of 0.17 (2 wt% OSNPs content). Thermostabilities of the nanocomposites were characterized by differential thermal gravimetric analysis. At the maximum rate of weight loss of EP‐BMI‐DDM/3 wt% OSNP, the temperature measured 452°C, which is 52°C higher than that of pure EP‐BMI‐DDM copolymers (400°C). The produced nanocomposites feature good thermostability and self‐lubrication can be widely used as wearable material under severe working conditions with higher temperature. POLYM. ENG. SCI., 59:274–283, 2019. © 2018 Society of Plastics Engineers     

Effects of nanosilica filler surface modification and compatibilization on the mechanical,thermal and microstructure of PP/EPR blends

Polypropylene/ethylene-propylene rubber/nanosilica (PP/EPR/nano-SiO₂) composites were prepared by a melt blending masterbatch process using a Brabender mixer. In order to improve the interfacial adhesion and achieve diverse desired properties of the composites, nanosilica surface silylation by means of two silane coupling agents: N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (AEAPTMS) and 3-methacryloxypropyltrimethoxysilane (MPTMS) was explored. The composites were also compatibilized using three compatibilizers: methyl methacrylate grafted PP (MMA-g-PP), glycidylmethacrylate grafted PP (GMA-g-PP) and maleic anhydride grafted PP (MAH-g-PP). The properties of the blends and the composites were examined using tensile and Izod impact tests, differential scanning calorimetry (DSC), thermogravimetric analysis (ATG) and scanning electron microscopy (SEM). According to the mechanical property evaluations, the incorporation of nano-SiO₂ particles into PP/EPR blend improved the tensile strength and Young’s modulus of the composites. The elongation and Izod impact strength were adversely affected. A significant improvement in the mechanical properties was obtained for the composites with AEAPTMS-SiO₂ and MAH-g-PP. The DSC results indicated that the incorporation of the modified silica and MAH-g-PP increased the crystallinity of the composites. However, no significant variation in the crystallinity was observed as a result of the addition of MMA-g-PP and GMA-g-PP. The TGA results revealed that the composites exhibit a higher thermal stability than that of the neat matrix. SEM micrographs of the fractured surfaces revealed a two-phase morphology with EPR nodules being dispersed in the PP matrix. SEM also indicated that the incorporation of MAH-g-PP into PP/EPR composites contributes to a better dispersion of the EPR phase and nano-SiO₂ particles in the polymer matrix.     

环氧树脂/稻壳SiO2纳米复合材料的热性能及拉伸性能研究

将稻壳用酸处理后在600 ℃焚烧得到纯度为99.3%、比表面积为212 m2/g的SiO2。经硅烷偶联剂γ-氨丙基三乙氧基硅烷（KH550）改性后的SiO2为无定形态,尺寸在30~50 nm之间。将改性后的稻壳SiO2与环氧树脂复合,利用热分析方法考察了纳米复合材料在N2气氛中的热性能,并采用万能材料试验机测试其拉伸性能。结果表明：稻壳SiO2的加入能有效增加环氧树脂/稻壳SiO2纳米复合材料的热稳定性,复合材料的起始分解温度（Ti）、分解速率最大时的温度（Tmax）以及失重50 %的分解温度（T50 %）均高于纯环氧树脂,并随稻壳SiO2含量的增加而增加。当环氧树脂/稻壳SiO2纳米复合材料的组成相同时,KH550改性的复合材料的Ti、Tmax和T50 %均比未经过KH550改性的高。随KH550用量增加,复合材料T50 %向高温方向移动。此外,复合材料的拉伸强度、断裂伸长率和模量也高于纯环氧树脂。     

Poly(vinyl alcohol) nanocomposites with different clays: Pristine clays and organoclays

Poly(vinyl alcohol) (PVA)/clay nanocomposites were synthesized using the solution intercalation method. Na ion‐exchanged clays [Na⁺–saponite (SPT) and Na⁺–montmorillonite (MMT)] and alkyl ammonium ion‐exchanged clays (C₁₂–MMT and C₁₂OOH–MMT) were used for the PVA nanocomposites. From the morphological studies, the Na ion‐exchanged clay is more easily dispersed in a PVA matrix than is the alkyl ammonium ion‐exchanged clay. Attempts were also made to improve both the thermal stabilities and the tensile properties of PVA/clay nanocomposite films, and it was found that the addition of only a small amount of clay was sufficient for that purpose. Both the ultimate tensile strength and the initial modulus for the nanocomposites increased gradually with clay loading up to 8 wt %. In C₁₂OOH–MMT, the maximum enhancement of the ultimate tensile strength and the initial modulus for the nanocomposites was observed for blends containing 6 wt % organoclay. Na ion‐exchanged clays have higher tensile strengths than those of organic alkyl‐exchanged clays in PVA nanocomposites films. On the other hand, organic alkyl‐exchanged clays have initial moduli that are better than those of Na ion‐exchanged clays. Overall, the content of clay particles in the polymer matrix affect both the thermal stability and the tensile properties of the polymer/clay nanocomposites. However, a change in thermal stability with clay was not significant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3208–3214, 2003     

Effect of filler content on the structure‐property behavior of poly(ethylene oxide) based polyurethaneurea‐silica nanocomposites

Poly(ethylene oxide) (PEO) based polyurethaneurea‐silica nanocomposites were prepared by solution blending and characterized by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Differential Scanning Calorimetry and tensile testing. The colloidal silica nanoparticles with an average size of 50 nm were synthesized by modified Stöber method in isopropanol. Silica particles were incorporated into three cycloaliphatic polyurethaneurea (PUs) copolymers based on PEO oligomers with molecular weights of 2,000, 4,600, and 8,000 g/mol. Hard segment content of PUs was constant at 30% by weight. Silica content of the PU nanocomposites varied between 1 and 20% by weight. Soft segment (SS) glass transition and melting temperatures slightly increased with increasing filler content for all the copolymers. Degree of SS crystallinity first increased with 1% silica incorporation and subsequently decreased by further silica addition. Elastic modulus and tensile strengths of PU copolymers gradually increased with increasing amount of the silica filler. Elongation at break values gradually decreased in PEO‐2000 based PU copolymer with increasing silica content, whereas no significant change was observed in PUs based on PEO‐4600 and PEO‐8000. Enhancement in tensile properties of the materials was mainly attributed to the homogeneous distribution of silica filler in polymer matrices and strong polymer‐filler interactions. POLYM. ENG. SCI., 58:1097–1107, 2018. © 2017 Society of Plastics Engineers