Preparation and characterization of magnetic poly(styrene–glycidyl methacrylate) microspheres for highly efficient protein adsorption by two‐stage dispersion polymerization

Micrometer‐sized superparamagnetic poly(styrene–glycidyl methacrylate)/Fe₃O₄ spheres were synthesized by two‐stage dispersion polymerization with modified hydrophobic Fe₃O₄ nanoparticles, styrene (St), and glycidyl methacrylate (GMA). The morphology and properties of the magnetic Fe₃O₄–P (St‐GMA) microspheres were examined by scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, and attenuated total reflectance. The average size of the obtained magnetic microspheres was 1.50 μm in diameter with a narrow size distribution, and the saturation magnetization of the magnetic microspheres was 8.23 emu/g. The magnetic Fe₃O₄–P (St‐GMA) microspheres with immobilized iminodiacetic acid–Cu²⁺ groups were used to investigate the adsorption capacity and selectivity of the model proteins, bovine hemoglobin (BHb) and bovine serum albumin (BSA). We found that the adsorption capacity of BHb was as high as 190.66 mg/g of microspheres, which was 3.20 times greater than that of BSA, which was only 59.64 mg/g of microspheres as determined by high‐performance liquid chromatography. With a rather low nonspecific adsorption, these microspheres have great potential for protein separation and purification applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43005.     

Magnetic polystyrene–palygorskite nanocomposite obtained by heterogeneous phase polymerization to apply in the treatment of oily waters

Water contaminated by oil poses challenges to the management of water resources. Magnetic nanoparticles has been issue of different potential applications including remotion oil from water. Magnetic polystyrene–palygorskite nanocomposites were prepared by a heterogeneous phase polymerization for the removal of organic contaminants from water. The organo‐Fe₃O₄‐palygorskite nanoparticles were coated with polystyrene, forming water repellent and oil absorbing surfaces to promote the removal of oil from the surfaces of nanocomposites by applying an external magnetic field. X‐ray fluorescence, X‐ray diffraction, scanning electron microscopy, zeta potential and size distribution measurement, surface area determination by BET, density measurement by He pycnometry, carbon grade determination, thermogravimetric analysis, Fourier‐transform infrared spectroscopy, Raman spectroscopy, and evaluation of hydrophobicity by contact angle were used to characterize the nanoparticles. The magnetic nanocomposite obtained showed excellent hydrophobicity, around 78° contact angle. In addition, oil removal capability tests were also performed, according to which the preliminary results indicated removal of approximately 98% of oil in synthetic oily water samples. The oil–water separation using this magnetic nanocomposite provides a promising alternative strategy for water treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46162.     

Synthesis,characterization, and properties of flexible magnetic nanocomposites of cobalt ferrite–polybenzoxazine–linear low‐density polyethylene

A simple method for the preparation of magnetic nanocomposites consisting of cobalt ferrite (CF; CoFe₂O₄) nanoparticles, polybenzoxazine (PB), linear low‐density polyethylene (LLDPE), and linear low‐density polyethylene‐g‐maleic anhydride (LgM) is described. The composites were prepared by the formation of benzoxazine (BA)–CF nanopowders followed by melt blending with LLDPE and the thermal curing of BA. The composites were characterized by X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, universal testing machine measurement, and vibrating sample magnetometry. The composites consisting of LLDPE, PB, and LgM (47.5L–47.5PB–5LgM) exhibited a higher tensile strength (23.82 MPa) than pure LLDPE and a greater elongation at break (6.11%) than pure PB. The tensile strength of the composites decreased from 19.92 to 18.55 MPa with increasing CF loading (from 14.25 to 33.25 wt %). The saturation magnetization of the composites containing 33.25 wt % CF was 18.28 emu/g, and it decreased with decreasing amount of CF in the composite. The composite films exhibited mechanical flexibility and magnetic properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Cr(III)‐containing Fe3O4/mercaptopropanoic acid‐poly(2‐hydroxyethyl acrylate) nanocomposite: Highly active magnetic catalyst for direct hydroxylation of benzene

In this study, polymer‐grafted magnetic nanoparticles containing chromium(III) ions incorporated onto Fe₃O₄/mercaptopropanoic acid‐poly(2‐hydroxyethyl acrylate) was prepared via a simple and in situ method. The obtained magnetic nanocomposite exhibited high catalytic activity and excellent selectivity in direct hydroxylation of benzene in the presence of hydrogen peroxide under solvent‐free condition. The magnetic catalyst could be also separated by an external magnet and reused seven times without any significant loss of activity/selectivity. Due to the Lewis acidity of the Fe³⁺ groups in the structure of magnetic nanoparticles, the high efficiency of this catalyst is possibly due to the synergetic effect of Cr³⁺ and Fe³⁺ groups in the structure of magnetic nanocomposite. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40383.     

Controlled release of protein from magnetite–chitosan nanoparticles exposed to an alternating magnetic field

In this research, the controlled release of proteins from magnetite (Fe₃O₄)–chitosan (CS) nanoparticles exposed to an alternating magnetic field is reported. Fe₃O₄–CS nanoparticles were synthesized with sodium tripolyphosphate (TPP) molecules as a crosslinking reagent. Bovine serum albumin (BSA) was used as a model protein, and its controlled release studied through the variation of the frequency of an alternating magnetic field. The results show the successful coating of CS and BSA on the Fe₃O₄ nanoparticles with an average diameter of 50 nm. Intermolecular interactions of TPP with CS and BSA were confirmed by Fourier transform infrared spectroscopy. The application of low‐frequency alternating magnetic fields to such magnetic CS nanoparticles enhanced the protein release properties, in which the external magnetic fields could switch on the unloading of these nanoparticles. We concluded that enhanced BSA release from nanoparticles exposed to an alternating magnetic field is a promising method for achieving both the targeted delivery and controlled release of proteins. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43335.     

PMMA‐grafted‐silica/PVC nanocomposites: Mechanical performance and barrier properties

Poly(vinyl chloride) (PVC)/SiO₂ nanocomposites were prepared via melt mixture using a twin‐screw mixing method. To improve the dispersion degree of the nanoparticles and endow the compatibility between polymeric matrix and nanosilica, SiO₂ surface was grafted with polymethyl methacrylate (PMMA). The interfacial adhesion was enhanced with filling the resulting PMMA‐grafted‐SiO₂ hybrid nanoparticles characterized by scanning electron microscopy. Both storage modulus and glass transition temperature of prepared nanocomposites measured by dynamic mechanical thermal analysis were increased compared with untreated nanosilica‐treated PVC composite. A much more efficient transfer of stresses was permitted from the polymer matrix to the hybrid silica nanoparticles. The filling of the hybrid nanoparticles caused the improved mechanical properties (tensile strength, notched impact strength, and rigidity) when the filler content was not more than 3 wt %. Permeability rates of O₂ and H₂O through films of PMMA‐grafted‐SiO₂/PVC were also measured. Lower rates were observed when compared with that of neat PVC. This was attributed to the more tortuous path which must be covered by the gas molecules, since SiO₂ nanoparticles are considered impenetrable by gas molecules. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Fe3O4/poly(acrylic acid) hybrid nanoparticles for water‐based drilling fluids

Because of the sizes of the pore throat are on the nanometer scale, nanoparticles with sizes on the nanoscale have been developed as candidates for plugging materials during drilling in shale formation. In this study, Fe₃O₄ nanoparticles were prepared by a coprecipitation method, and then, Fe₃O₄/poly(acrylic acid) (PAA) hybrid nanoparticles were obtained through the modification of the Fe₃O₄ nanoparticles with PAA. The hybrid nanoparticles were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and thermogravimetric analysis. The magnetic properties, salt tolerance, and compatibility with sulfomethylated phenolic resin of the nanoparticles were studied. The plugging properties of the Fe₃O₄/PAA hybrid nanoparticles were evaluated by filtration testing of the filter cakes at ambient temperature and 80 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43967.     

High‐mechanical‐strength ferrohydrogels with a magnetically dispersed phase as multifunctional crosslinkers

In this article, we report a facile strategy for preparing high‐mechanical‐strength ferrohydrogels containing magnetic nanoparticles homodispersed by a thermodynamically stable Pickering emulsion (PE). After the monomers were mixed with the PE, including methacryloxy propyl trimethoxyl silane emulsified by ferric oxide (Fe₂O₃) nanoparticles as the dispersed phase, hydrogels were synthesized by free‐radical polymerization. In contrast to conventional hydrogels crosslinked by a molecular crosslinker, in our new approach, the magnetic PE particles served as individual, multifunctional crosslinkers. Characterizations of the swelling behavior, the mechanical properties, and other properties indicated that our ferrohydrogels exhibited outstanding physical performances that were superior to those of traditional hydrogels and magnetic responsiveness. These ferrohydrogels may have applications in soft and controllable actuators. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41950.     

Influence of copper oxide nanomaterials in a poly(ether sulfone) membrane for improved humic acid and oil–water separation

In this study, self‐synthesized copper(I) oxide (Cu₂O) nanoparticles were incorporated in poly(ether sulfone) (PES) mixed‐matrix membranes (MMMs) through the phase‐inversion method. A cubic arrangement and crystallite size of 28 nm was identified by transmission electron microscopy and X‐ray diffraction (XRD) for the as‐synthesized Cu₂O particles. The pristine PES membrane had a higher contact angle value of 88.50°, which was significantly reduced up to 50.10° for 1.5 wt % PES/Cu₂O MMMs. Moreover, XRD analysis of the Cu₂O‐incorporated PES membrane exhibited a new diffraction pattern at 36.46°. This ensured that the Cu₂O nanoparticles were distributed well in the PES matrix. Interestingly, the water permeability progressively improved up to 66.72 × 10^?9 m s^?1 kPa^?1 for 1.5 wt % PES/Cu₂O MMMs. Furthermore, the membrane performances were also evaluated with different feed solutions: (1) bovine serum albumin, (2) humic acid, and (3) oil–water. The enhanced rejection and lower flux reduction percentage were observed for hybrid membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43873.     

Multi‐responsive polymeric microcontainers for potential biomedical applications: synthesis and functionality evaluation

Temperature and pH responsive poly(N‐isopropylacrylamide‐co‐methacrylic acid) (P(NIPAAm‐co‐MAA)) microcontainers with encapsulated magnetic nanoparticles in the shell were prepared by a two‐stage distillation precipitation polymerization. PMAA@Fe₃O₄/P(NIPAAm‐co‐MAA) core–shell nanoparticles were synthesized by the second‐stage polymerization of NIPAAm, MAA and N, N′‐methylenebisacrylamide as crosslinker in the presence of magnetic nanoparticles and PMAA as core. These novel triple‐functional microcontainers were prepared by selective removal of the PMAA core in water. Daunorubicin hydrochloride (DNR) was loaded into the microcontainers and the release profile was studied by UV–visible spectroscopy. The synthesized nanostructures were characterized with transmission and scanning electron microscopy, X‐ray diffraction and Fourier transform infrared spectroscopy. The magnetic properties were evaluated by vibrating sample magnetometry. The shrink and swelling behavior was studied by dynamic light scattering. Copyright © 2012 Society of Chemical Industry     

Interforce initiated by magnetic nanoparticles for reducing internal concentration polarization in CTA forward osmosis membrane

The interforce between the magnetic composite forward osmosis (FO) membranes and the magnetic draw solution was proposed to reduce the internal concentration polarization (ICP) of FO process, and realized the synergetic permeability improvement of resultant FO membranes. The key factor was the successful fabrication of the Fe₃O₄ magnetic nanoparticles (MNPs) with small‐size and narrow distribution via co‐precipitation method. The cellulose triacetate (CTA) magnetic composite FO membranes were fabricated using Fe₃O₄ as additive via in situ interfacial polymerization, and named CTA‐Fe₃O₄. Dynamic light scattering (DLS) and zeta results showed that the coated sodium oleate on the MNPs explained their reducing aggregation and the stability of various pHs. The MNPs' surface segregation during demixing process resulted in the improvement of hydrophilicity, Fe content and roughness of resultant CTA‐Fe₃O₄ composite FO membranes. Furthermore, the in situ interfacial polymerization resulted in the formation of the polyamide selective layer, and the CTA‐Fe₃O₄ membrane's N content was 11.02% to 11.12%. The permeability properties (FO and pressure retarded osmosis modules) were characterized using 1.0M NaCl and 100 mg/L Fe₃O₄ as draw solutions, respectively. The results indicated that the higher concentration of MNPs supplied more interforce and better FO permeability properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44852.     

Preparation and characterization of magnetic star‐shaped amphiphilic copolymer nanoparticles of S‐Fe3O4‐PLA‐b‐MPEG

Magnetic star‐shaped amphiphilic copolymers (S‐Fe₃O₄‐PLA‐b‐MPEG) consisting of Fe₃O₄ as the core, poly(L ,D ‐lactide) (PLA) as the inner layer, and monomethyl polyethylene glycol (MPEG) as the out shell were synthesized. The syntheses included ring‐opening polymerization of L ,D ‐lactide initiated by hydroxyl modified Fe₃O₄ (Fe₃O₄‐(OH) _n), followed by the esterification of the PLA with MPEG. The structure of the star block copolymers were characterized by Fourier Transform infrared spectroscopy, thermogravimetric analysis, X‐ray diffraction, transmission electron microscopy, nanoparticle size analyzer, and vibrating sample magnetometer. The nanoparticles in aqueous solution were made from the amphiphilic star copolymer. The average size of the nanoparticles was adjustable and increased with the increase of the PLA segments in the copolymer. The cytotoxicity grade of the nanoparticles was zero determined by the analysis of cytotoxicity. The nanoparticles could potentially be used as the drug vehicles for magnetic‐response controlled release. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

A novel method to prepare magnetic polymer‐based anion exchangers and their application

Magnetic microspheres with ion‐exchange features were prepared by applying a swelling and penetration process using polystyrene–divinylbenzene‐based anion‐exchange resins as starting materials. The polymeric anion‐exchange particles were swollen with an aqueous solution of N‐methyl‐2‐pyrrolidone, followed by incubation with superparamagnetic iron oxide nanoparticles to allow them to penetrate into the swollen particles. The pH value in the solution of magnetic nanoparticles could significantly influence the uptake of magnetic nanoparticles by the swollen anion‐exchange particles. Higher amounts of magnetic nanoparticles entrapped within anion exchangers could be achieved at pH 10–12. An increase in the concentration of magnetic nanoparticles led to a higher density of magnetic nanoparticles entrapped within the interior of anion exchangers and, thus, higher magnetization of the magnetic anion exchangers. Loading of the magnetic nanoparticles onto the exchanger had no effect on anion‐exchange functionality. The utility of the resulting magnetic anion‐exchange resins was demonstrated for the isolation of plasmid pEGFP‐C1 from Escherichia coli cell lysates. The magnetic anion‐exchange microspheres could be easily collected within a few seconds in a magnetic field. Thus, automation of the protocol for DNA isolation using these magnetic anion‐exchange resins has a high potential. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40725.     

“One‐pot” synthesis of well‐defined functional copolymer and its application as tumor‐targeting nanocarrier in drug delivery

A one‐pot synthesis is developed for PEG₆₀₀‐b‐poly(glycerol monoacrylate) (PEG₆₀₀‐b‐PGA), by which folate and superparamagnetic iron oxide nanoparticles (SPIONs) are assembled to form folic acid‐conjugated magnetic nanoparticles (FA‐MNPs) as a tumor targeting system. The synthesis consists of a “click” reaction and atom transfer radical polymerization (ATRP) to obtain the well‐defined furan‐protected maleimido‐terminated PEG₆₀₀‐b‐poly(solketal acrylate) (PEG₆₀₀‐b‐PSA) copolymer. After deprotection, the key copolymer N‐maleimido‐terminated PEG₆₀₀‐b‐PGA is successfully conjugated with thiol derivatives of folate and FITC, respectively. FA‐MNPs are developed by assembling of the resulting polymer FA‐PEG₆₀₀‐b‐PGA with SPIONs, and characterized for their size, surface charge, and superparamagnetic properties. To investigate the cellular uptake of the nanoparticles by Hela cells and φ2 cells using fluoresce technique, FA‐FITC‐MNPs are also obtained by assembling of FA‐PEG₆₀₀‐b‐PGA, FITC‐PEG₆₀₀‐b‐PGA with SPIONs. Qualitative and quantitative determinations of FA‐FITC‐MNPs show that the particles specifically internalized to Hela cells. No significant cytotoxicity is observed for these two kinds of cell lines. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40405.     

Multifunctional hybrid magnetite nanoparticles with pH‐responsivity,superparamagnetism and fluorescence

Multifunctional hybrid nanoparticles, Fe₃O₄@poly[(2‐dimethylamino)ethyl methacrylate]‐block‐poly(2‐hydroxyethyl methacrylate)‐graft‐carbazole, with pH‐responsivity, superparamagnetism and fluorescence for targeted drug delivery and release have been synthesized. The nanoparticles have a core‐shell structure as determined from transmission electron microscopy, pH‐responsivity as determined from hydrodynamic radius analysis, superparamagnetism as determined from vibrating sample magnetometry and fluorescence as determined from fluorescence spectroscopy and fluorescence microscopy. The release behavior of model drug progesterone indicates that the release rate can be effectively controlled by altering the pH of the environment. The multifunctional nanoparticles could be applied extensively in targeted drug delivery and release, and with fluorescence they can serve as efficient tracers to record magnetic targeting routes. Copyright © 2011 Society of Chemical Industry     

Facile synthesis,characterization and material properties of a novel poly(vinyl cinnamate)/ nickel oxide nanocomposite

A poly(vinyl cinnamate) (PVCin) composite was synthesized by a simple one step in situ polymerization of vinyl cinnamate with nickel oxide (NiO) nanoparticles. The structural, morphological and thermal properties of the nanocomposite were characterized using Fourier transform (FT)‐Raman, FT infrared (FTIR) and UV spectroscopies, X‐ray diffraction (XRD), high‐resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), differential scanning calorimetry and vibrating sample magnetometry (VSM) measurements. FT‐Raman, FTIR and UV spectroscopy results revealed the characteristic absorption and shifts of peaks of the polymer matrix, the shifts being attributed to the interaction of NiO nanoparticles with the polymer chains. The structural and morphological analysis using XRD, HRTEM and FESEM showed the uniform arrangement of nanoparticles within the polymer chains. VSM showed the ferromagnetic nature of the composite with an increasing saturation of magnetism. The glass transition temperature (T_g) of the composite was higher than that of pure PVCin and T_g of the composite increased with increasing nanoparticle content. The electrical resistivity of the nanocomposite was studied from AC and DC conductivity measurements. AC and dielectric properties were markedly enhanced in the whole range of frequency due to the presence of NiO nanoparticles. DC conductivity of the nanocomposite was much higher than that of PVCin and the conductivity of the nanocomposite increased with increasing content of NiO nanoparticles. © 2016 Society of Chemical Industry     

Isotactic polypropylene metal oxide and silica nanocomposites by a two‐step process comprising in situ olefin polymerization and melt compounding

Nanocomposites of isotactic polypropylene (iPP) with 0.5 wt% filler of MgO@Mg(OH)₂ (35 nm) or silicon dioxide (20–60 nm) or barium titanate (50 nm) nanoparticles were obtained from melt compounding of filler masterbatches with commercial iPP. The masterbatches with 5 wt% nanofiller were prepared in an in situ polymerization procedure using a metallocene/methylaluminoxane (MAO) catalyst system that was supported on the respective oxides. The original agglomerates of the nanoparticles were broken up by treatment with dibutylmagnesium for MgO@Mg(OH)₂, and with ultrasound in the presence of MAO for SiO₂ and BaTiO₃. The tacticity (98% mmmm) of the in situ formed PP was not influenced by the presence of the nanofillers. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy mapping show a fine dispersion of single particles and small clouds or clusters. The primary nanoparticles appear to be surrounded by polymer. The elongation at break was decreased to 50, 17 and 9% for MgO@Mg(OH)₂), SiO₂ and BaTiO₃, respectively. After melt compounding with iPP, a homogeneous single‐particle distribution of the oxidic nanoparticles was found in the resulting composites with 0.5 wt% filler content. © 2019 Society of Chemical Industry     

High performance electrospun PVdF‐HFP/SiO2 nanocomposite membrane electrolyte for Li‐ion capacitors

Electrospun poly[(vinylidene fluoride)‐co ‐hexafluoropropylene]/silica (PVdF‐HFP/SiO₂) nanocomposite polymer membranes (esCPMs) were prepared by incorporating different weight percentages of SiO₂ nanoparticles onto electrospun PVdF‐HFP by electrospinning technique. The surface morphology of electrospun PVdF‐HFP nanocomposite membranes was characterized by scanning electron microscopy. The effect of SiO₂ nanoparticles incorporation onto electrospun PVdF‐HFP polymer membranes (esPMs) has been studied by XRD, DSC, TGA, and tensile analysis. The electrospun PVdF‐HFP/SiO₂ based nanocomposite membrane electrolytes (esCPMEs) were prepared by soaking the corresponding esCPMs into 1 M LiPF₆ in EC:DMC (1:1 vol/vol %). The ionic conductivity of the esCPMEs was studied by AC‐impedance studies and it was found that the incorporation of SiO₂ nanoparticles into PVdF‐HFP membrane has improved the ionic conductivity from 1.320 × 10^?3 S cm^?1 to 2.259 × 10^?3 S cm^?1. The electrochemical stability of the esCPME was studied by linear sweep voltammetry studies and it was found to be 2.87 V. Finally, a prototype LiCo_0.2Mn_1.8O₄//C Li‐ion capacitor (LIC) cell was fabricated with esCPME, which delivered a discharge capacitance of 128 F g^?1 at the current density of 1 A g^?1 and retained 86% of its discharge capacitance even after 10,000 cycles. These results demonstrated that the esCPMEs could be used as promising polymer membrane electrolyte for LICs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45177.     

Synthesis and characterization of magnetic and fluorescent styrene co‐polymer nanofiber

F luorescent and magnetic poly(styrene) (PS) based random co‐polymer nanofiber was synthesized in a controlled manner via chemical polymerization in three steps. A fluorescent and magnetic nanohybrid {Fe₃O₄/Congored (CR)} was separately prepared and chemically grafted onto the epichlorohydrin (ECH) units of the random co‐polymer. Characterizations of the above synthesized polymers were done with the help of Fourier transform infrared (FTIR) spectroscopy, UV–visible spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, fluorescence emission spectroscopy, field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) measurement, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC) like analytical techniques. The FESEM results indicated that after the grafting of nanohybrid onto the random co‐polymer backbone, the polymer exhibited a nanofiber like morphology. Due to the surface functionalization and encapsulation reactions, the magnetic moment value of the nanohybrid and its nanocomposites were found to be reduced. Synthesis and characterization of magnetic and fluorescent random co‐polymer based nanofiber is the primary target of the present investigation and its application is extended to the catalysis field. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42796.     

Enhancement of mechanical and tribological properties in ring‐opening metathesis polymerization functionalized molybdenum disulfide/polydicyclopentadiene nanocomposites

This study focuses on the possibility of improving performance properties of polydicyclopentadiene (PDCPD) nanocomposites for engineering applications using nanoparticles. In this article, molybdenum disulfide/polydicyclopentadiene (MoS₂/PDCPD) nanocomposites have been prepared by in situ ring‐opening metathesis polymerization using reaction injecting molding (RIM) process. To enhance the interfacial adhesion between the fillers and PDCPD matrix, the surface modified MoS₂ nanoparticles hybridized with dialkyldithiophosphate (PyDDP) were successfully prepared by in situ surface grafting method. The effect of low MoS₂ loadings (<3 wt %) on the mechanical and tribological behaviors of PDCPD was evaluated. The results indicated that the friction coefficient of the MoS₂/PDCPD nanocomposites was obviously decreased and the wear resistance of nanocomposites was greatly improved by the addition of PyDDP‐hybridized MoS₂ nanoparticles; meanwhile, the mechanical properties were also enhanced. The MoS₂/PDCPD nanocomposites filled with 1 wt % PyDDP‐hybridized MoS₂ exhibited the best mechanical and anti‐wear properties. The friction coefficient was shown to decrease by more than 40% compared to pure PDCPD by incorporating just 1 wt % hybridized MoS₂ nanoparticles, and modest increase in modulus and strength was also observed. The reinforcing and wear‐resistant mechanisms of MoS₂/PDCPD nanocomposites were investigated and discussed by scanning electron microscopy. The well interfacial compatibility between the particle/matrix interfaces played an important role for the improved mechanical and tribological properties of MoS₂/PDCPD nanocomposites in very low MoS₂ loadings. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013