Effect of octa(aminopropyl) polyhedral oligomeric silsesquioxane (OapPOSS) functionalized graphene oxide on the mechanical,thermal, and hydrophobic properties of waterborne polyurethane composites

A novel graphene nanomaterial functionalized by octa(aminopropyl) polyhedral oligomeric silsesquioxane (OapPOSS) was synthesized and then confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), Raman spectroscopy, X‐ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy with energy‐dispersive X‐ray spectroscopy (SEM EDX), atomic force microscopy, and X‐ray diffraction. The obtained functionalized graphene (OapPOSS‐GO) was used to reinforce waterborne polyurethane (WPU) to obtain OapPOSS‐GO/WPU nanocomposites by in situ polymerization. The thermal, mechanical, and hydrophobic properties of nanocomposites as well as the dispersion behavior of OapPOSS‐GO in the polymer were investigated by TGA, a tensile testing machine, water contact angle tests, and field emission SEM, respectively. Compared with GO/WPU and OapPOSS/WPU composites, the strong interfacial interaction between OapPOSS‐GO and the WPU matrix facilitates a much better dispersion and load transfer from the WPU matrix to the OapPOSS‐GO. It was found that the tensile strength of the OapPOSS‐GO/WPU composite film with 0.20 wt % OapPOSS‐GO exhibited a 2.5‐fold increase in tensile strength, compared with neat WPU. Better thermal stability and hydrophobicity of nanocomposites were also achieved by the addition of OapPOSS‐GO. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44440.     

Synthetic Ni‐talc as filler for producing polyurethane nanocomposites

New synthetic Ni‐talc was used as filler in the synthesis of polyurethane (PU) nanocomposites by in situ polymerization and to emphasize the contribution of the new material compared with natural talc. Good dispersion of Ni‐talc was supported by homogeneous green coloration observed in the polymer matrix. X‐ray diffraction (XRD) analyses indicate the intercalation of polymeric matrix into the filler layers by the increase in d₀₀₁‐spacing value of the Ni‐talc for the nanocomposites when compared to the pristine filler. The nanocomposites obtained with synthetic talc showed an improvement in the crystallization temperature and in thermal stability when compared to pure PU and the composite obtained with natural talc. The young modulus of PU/talc materials containing both Ni‐talc and natural talc were slight higher than pure PU. As shown by scanning electron microscope (SEM), Ni‐talc fillers were well dispersed into the polymeric matrix probably due to the good compatibility of both phases filler/polymer mainly achieved by the filler OH interaction with the urethane group of the polymeric chain. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41854.     

Preparation and characterization of chitosan/α‐zirconium phosphate nanocomposite films

Nano‐fillers play an important role in the final structure and properties of nanocomposites. The objective of the work presented here was to prepare nanocomposite films of chitosan/α‐zirconium phosphate using a casting process, with α‐zirconium phosphate (α‐ZrP) as nano‐filler and chitosan as matrix. The effects of α‐ZrP on the structure and properties of the nanocomposites were investigated. X‐ray diffraction patterns showed that α‐ZrP crystals were intercalated by n‐butylamine. The results from scanning electron microscopy and transmission electron microscopy indicated that α‐ZrP could be uniformly dispersed in the chitosan matrix when α‐ZrP loading in the composites was less than 2 wt%. A strong interaction between α‐ZrP and chitosan formed during the film‐forming process. Tensile testing showed that the tensile strength and elongation at break of nanocomposite films achieved maximum values of 61.6 MPa and 58.1%, respectively, when α‐ZrP loading was 2 wt%. The parameter B calculated from tensile yield stress according to the Pukanszky model was used to estimate the interfacial interaction between the chitosan matrix and α‐ZrP. Films with a loading of 2 wt% α‐ZrP had the highest B value (3.2), indicating the strongest interfacial interaction. The moisture uptake of the nanocomposites was reduced with addition of α‐ZrP. It can be concluded that α‐ZrP as nano‐filler in a chitosan matrix can enhance the mechanical properties of nanocomposites due to the strong interactions between α‐ZrP and chitosan. Copyright © 2010 Society of Chemical Industry     

Synergistic reinforcement of NBR by hybrid filler system including organoclay and nano‐CaCO3

Rubber nanocomposites containing one type of nanofiller are common and are widely established in the research field. In this study, nitrile rubber (NBR) based ternary nanocomposites containing modified silicate (Cloisite 30B) and also nano‐calcium carbonate (nano‐CaCO₃) were prepared using a laboratory internal mixer (simple melt mixing). Effects of the hybrid filler system (filler phase have two kind of fillers) on the cure rheometry, morphology, swelling, and mechanical and dynamic–mechanical properties of the NBR were investigated. Concentration of nano‐CaCO₃ [0, 5, 10, and 15 parts per one hundred parts of rubber by weight (phr)] and organoclay (0, 3, and 6 phr) in NBR was varied. The microstructure and homogeneity of the compounds were confirmed by studying the dispersion of nanoparticles in NBR via X‐ray diffraction and field emission scanning electron microscopy. Based on the results of morphology and mechanical properties, the dual‐filler phase nanocomposites (hybrid nanocomposite) have higher performance in comparison with single‐filler phase nanocomposites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42744.     

Fabrication of regenerated cellulose nanoparticles/waterborne polyurethane nanocomposites

Regenerated cellulose nanoparticles (RCNs) are ideal materials for new biomass polymer composites industries. RCNs and composites of RCNs and water‐borne polyurethane (RCN/WPU) were prepared using a facile and environmentally friendly approach without the use of any harmful chemicals. The morphological, thermal, and mechanical properties of the RCN/WPU nanocomposite were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), rheometer, wide‐angle X‐ray diffraction, and enzymatic hydrolysis. RCNs exhibited low crystallinity upon regeneration with an NaOH‐based aqueous solution, and were identified by SEM and TEM to consist of the more thermodynamically stable cellulose form. TGA showed that the thermal stability of RCN/WPU nanocomposites was increased by the addition of RCNs. Finally, enzymatic hydrolysis using cellulase indicated that the biodegradability of RCN/WPU nanocomposites was also improved. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46633.     

Effect of the variation in the weight percentage of the loading and the reduction in the nanosizes of CaSO4 on the mechanical and thermal properties of styrene–butadiene rubber

The incorporation of fillers into elastomers has profound effects on the mechanical, physical, and thermal properties of the nanocomposites that form. In this study, styrene–butadiene rubber as a matrix was reinforced separately with 10‐, 15‐, or 23‐nm CaSO₄, which was synthesized by an in situ deposition technique. The mixing and compounding were performed on a two‐roll mill, and sheets were prepared in a compression‐molding machine. Properties such as the swelling index, specific gravity, tensile strength, elongation at break, modulus at 300% elongation, Young's modulus, hardness, and abrasion resistance were measured. The morphology of the rubber nanocomposites was also performed with scanning electron microscopy to study the dispersion of the nanofiller in the rubber matrix. The thermal decomposition of the rubber nanocomposites was studied with thermogravimetric analysis, and the results were compared with those of commercial CaSO₄‐filled styrene–butadiene rubber. A reduction in the nanosizes of CaSO₄ led to an enhancement of the mechanical, physical, and thermal properties of the rubber nanocomposites. Above a 10 wt % filler loading, the styrene–butadiene rubber showed a reduction in all properties. This effect was observed because of the agglomeration of the nanoparticles in the rubber matrix. The thermodynamic parameters were also studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2018–2026, 2007     

Investigation on the mechanical performances of ternary nylon 6/SEBS elastomer/nano‐SiO2 hybrid composites with controlled morphology

The distribution of maleated styrene‐hydrogenated butadiene‐styrene (mSEBS) elastomer and nano‐SiO₂ in nylon 6 matrix was controlled by varying the blending procedure. Nano‐SiO₂ particles with different surface properties (hydrophilic versus hydrophobic) were adopted to adjust their interactions with other components. Two different structures, separate dispersion of nano‐SiO₂ and elastomer particles as well as encapsulation of nano‐SiO₂ fillers by the elastomer, were obtained. The structures were confirmed through scanning electron microscope (SEM) investigation. The mechanical measurement results showed that the microstructure and the interactions among the components had dramatic influences on the final mechanical properties, especially Izod fracture toughness, for the ternary nanocomposites. The nanocomposites containing hydrophilic nano‐SiO₂ had better mechanical performances compared with the composites filled with hydrophobic SiO₂ when they were in the same microstructure. The nanocomposites with separate dispersion structure showed higher stiffness compared with those of encapsulation type. However, the separately dispersed nano‐SiO₂ particles restricted the cavitation of elastomer phases that led to low toughening effectiveness. The difference of cavitation intensity for elastomer phase was revealed by SEM investigation on the facture surfaces for the nanocomposites with the two different microstructures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

WPU/CB/GO nanocomposites: in situ polymerization preparation,thermal, and anticorrosion performance evaluation

In this paper, composite fillers including graphene oxide and carbon black had been applied to modify pure waterborne polyurethane (WPU) and a new nanocomposite was prepared by in situ polymerization, whose structure was characterized by Fourier transform infrared spectroscopy that demonstrated interfacial interactions existing between the filler particles and the hard segments of WPU chains. Meanwhile, thermal properties of prepared nanocomposites were enhanced after adding composite fillers as shown in the results of thermogravimetric analysis and differential scanning calorimetry curves, which could be explained by several factors including strong interface interaction between organic phase and inorganic phase verified by infrared spectra and scanning electron microscopy as well as transmission electron microscopy, good dispersion and barrier effect of the composite fillers, reinforced crosslinking density of the system. Additionally, the contact angle and anticorrosion performance of the nanocomposite films were heightened after adding fillers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48716.     

Effects of starch nanocrystal‐graft‐polycaprolactone on mechanical properties of waterborne polyurethane‐based nanocomposites

Based on a “graft from” strategy, the surface of starch nanocrystals (StN) were functionalized by grafting with polycaprolactone (PCL) chains via microwave assisted ring‐opening polymerization (ROP). The modified natural nanoparticles were then compounded into a PCL‐based waterborne polyurethane as matrix. The structural and mechanical properties of the WPU/StN‐g‐PCL nanocomposites were characterized by XRD, FTIR, SEM, DSC, DMA, and tensile testing. It was interesting to note that a loading‐level of 5 wt % StN‐g‐PCL resulted in a simultaneous enhancement of tensile strength and elongation at break, both of which were higher than those of neat WPU. This enhancement was attributed to the uniform dispersion of StN‐g‐PCL because of its nano‐scale size, the increased entanglements mediated with grafted PCL chains, and the reinforcing function of rigid StN. Increasing the StN‐g‐PCL content however caused the StN‐g‐PCL to self‐aggregate as crystalline domains, which impeded improvement in tensile strength and elongation at break, but significantly enhanced Young's modulus. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of Epoxy-TiO2 Nanocomposites: A Study on Sliding Wear Behavior,Thermal and Mechanical Properties

Epoxy-based nanocomposites containing functionalized nanoscale TiO₂ with 0.5%, 1%, 5%, and 10% by weight were developed. A coupling agent was employed to functionalize nano titania for better compatibility of nanoscale particles with dispersing media. Under sliding conditions, the specific wear rate and coefficient of friction were evaluated. The dispersion of fillers in the matrix was also studied using scanning electron microscopy. The wear mechanism is studied in correlation with a micrograph of the worn-out surface of nanocomposites. The various mechanical properties and thermal stability were studied and the influences of nanofiller loading on these parameters were observed.     

氧化石墨烯/氯丁橡胶复合材料的制备及性能研究

通过乳液复合方法制得氧化石墨烯/氯丁橡胶纳米复合材料。研究氧化石墨烯/氯丁橡胶复合材料的硫化特性,力学性能,动态力学性能,耐磨性能。采用扫描电镜研究氧化石墨烯和无机填料在橡胶基体中的分散性。结果表明,氧化石墨烯在氯丁橡胶中具有良好分散性以及改善其他无机填料的分散性,氧化石墨烯的加入可以明显改善加工安全性,提高氯丁橡胶的力学性能,提高氯丁橡胶储能模量及耐磨性。当氧化石墨烯填充量为5phr时,氧化石墨烯/氯丁橡胶的综合性能最佳。     

Influence of the surface modification of a filler on the properties of high‐impact polystyrene composites

A novel technique of surface modification was used to treat nanomodified aluminum trihydrate (nano‐CG‐ATH). The results of the surface modification were characterized with transmission electron microscopy and Fourier transform infrared spectra. The effects of the surface modification on the properties of high‐impact polystyrene (HIPS) composites were studied with limiting oxygen index (LOI) and mechanical tests. The dispersion of nano‐CG‐ATH in the HIPS matrix and the interfacial adhesion between them were observed with transmission electron microscopy and scanning electron microscopy. The experimental results demonstrate that the surface of nano‐CG‐ATH was successfully grafted by an organic substance, and the dispersion of treated nano‐CG‐ATH in ethanol was better than that of untreated nano‐CG‐ATH. At high loadings, the mechanical properties and LOI values of the HIPS composites with treated nano‐CG‐ATH were higher than those of the HIPS composites with untreated nano‐CG‐ATH. The dispersion of treated nano‐CG‐ATH in the HIPS matrix was better than that of untreated nano‐CG‐ATH in the HIPS matrix. Also, the interfacial adhesion between the HIPS matrix and treated nano‐CG‐ATH was better than that between the HIPS matrix and untreated nano‐CG‐ATH. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites

Poly(lactic acid) (PLA)/nano zinc oxide/copper chlorophyll acid (CCA) antibacterial nanocomposites with excellent mechanical properties were prepared in the presence of a chain extender named tolylene diisocyanate (TDI). The effect of the chain extender on the PLA long chain was confirmed by the increased molecular weight shown in the mass flow rate and gel permeation chromatography. Escherichia coli were adopted to examine the antibacterial ability of the blends. The effect of CCA is also discussed with regard to the enhancement of the antibacterial effect of zinc oxide (ZnO) over E. coli. Scanning electron microscopy and transmission electron microscopy were used to view the agglomeration and dispersion of ZnO in the PLA matrix. Differential scanning calorimetry and thermogravimetric analysis revealed a relatively stable thermal performance of the nanocomposites with and without TDI. A sharp increase in the mechanical properties was also observed after the addition of the chain extender under different processing conditions. Additionally, we found that the nanocomposites with the incorporation of TDI and the masterbatches in batches effectively improved the mechanical properties of PLA/ZnO/CCA without a sacrifice of the antibacterial effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41561.     

Effect of isocyanate‐modified fumed silica on the properties of poly(butylene succinate) nanocomposites

Using the grafting method on a silica surface with PBS molecules, we prepared novel poly(butylene succinate) (PBS)/silica nanocomposites to enhance dispersibility and interfacial adhesion between silica particles and the PBS matrix, and also investigated the effects of silica‐g‐PBS on the PBS matrix using differential scanning calorimetry, thermogravimetric analysis, transmission electron microscopy, a tensile testing machine, and rheometry. The thermal stability, mechanical properties, and rheological properties of PBS nanocomposites containing silica‐g‐PBS was remarkably improved because of the surface characteristics of the silica grafted with PBS molecules, which provided good compatibility and dispersion. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and properties of natural rubber nanocomposites with solid‐state organomodified montmorillonite

A novel organomodified montmorillonite prepared by solid‐state method and its nanocomposites with natural rubber were studied. The nanocomposites were prepared by traditional rubber mixing and vulcanizing process. The properties of solid‐state organomodified montmorillonite were investigated by Fourier‐transform infrared spectroscopy (FITR) and thermogravimetric analysis (TGA). The dispersion of the layered silicate in rubber matrix was characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the nanocomposites consisting of solid‐state organomodified montmorillonite and natural rubber are obtained. The solid‐state organomodified montmorillonite can not only accelerate the curing process, but also improve the mechanical and aging resistance properties of NR. The properties improvement caused by the fillers are attributed to partial intercalation of the organophilic clay by NR macromolecules. In addition, the dynamic mechanical analysis (DMA) results showed a decrease of tanδmax and increase of T_g when the organoclay is added to the rubber matrix, which is due to the confinement of the macromolecular segments into the organoclay nanolayers and the strong interaction between the filler and rubber matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mineral filler reinforcement for commingled recycled‐plastic materials

Three types of mineral fillers, gypsum, wollastonite, and talc, were investigated for their ability to modify the mechanical properties of commingled recycled‐plastic composites containing 0.07–0.26 v/v of filler. Mechanical test results showed that the talc reinforced composites were significantly better in mechanical properties when compared with the gypsum and wollastonite composites. Scanning electron microscopy (SEM) showed that gypsum formed large agglomerates in the matrix. Interfacial adhesion between filler and matrix was evaluated using simple empirical models. To enhance the adhesion, talc, and wollastonite were pretreated with silane coupling agents, 3‐methacryloxypropyltrimethoxy silane (γ‐MPS) and 3‐aminopropyltriethoxy silane (γ‐APS). This did not result in any significant improvement to the material properties. The γ‐APS treatment, however, increased the tensile properties of the composites by ～ 5% when compared with the γ‐MPS treatment. The SEM investigations showed that the γ‐APS treatment provided better adhesion of filler particles and hence voids were less likely to form in the matrix when compared with the γ‐MPS composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and properties of ethylene propylene rubber (EPR)–clay nanocomposites based on maleic anhydride‐modified EPR and organophilic clay

Ethylene propylene rubber–clay nanocomposites (EPR–CNs) were prepared by melt‐compounding maleic anhydride modified EPR (EPR‐MA) with organophilic clay, and their properties were examined. Silicate layers of organophilic clay were found to exfoliate and homogeneously disperse into the nanometer level in the nanocomposites by transmission electron microscopy observation. EPR–CNs exhibited higher tensile moduli compared to EPR‐MA and composites containing conventional fillers such as carbon black, talc. The storage moduli of EPR–CNs were also higher than those of EPR‐MA and the conventional composites. Creep resistances of EPR–CNs were much improved compared for EPR‐MA. Degree of swelling in hexadecane was remarkably restricted. Improvement of these properties is caused because dispersed silicate layers have much large interface with the EPR matrix and are thought to strongly restrain the EPR polymer chains. Nanocomposite technology using small amount of silicate layers is useful to improve properties of thermoplastic elastomer. Various kinds of thermoplastic elastomers are expected to be produced by loading of silicate layers with or without conventional fillers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 758–764, 2004     

Preparation and properties of waterborne polyurethane/antimony doped tin oxide nanocomposite coatings via sol–gel reactions

Various amounts of antimony doped tin oxide (ATO) nanoparticles were incorporated into waterborne polyurethane (WPU) dispersions by sol–gel reactions. The dispersion state and morphology investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the nanoparticles can disperse in the matrix uniformly. The analysis of visible–near infrared spectra (VIS–NIR) suggested that the WPU/ATO coatings show both low near infrared transmittance (35%) and high visible light transmittance (76%). The heat‐insulation effect measurement demonstrated that the WPU/ATO coatings could prevent heat transmission effectively. It was also found that the introduction of ATO nanoparticles can improve the mechanical properties significantly. POLYM. COMPOS., 35:1169–1175, 2014. © 2013 Society of Plastics Engineers     

Effect of SWCNT dispersion on epoxy nanocomposite properties

In nanocomposites containing single wall carbon nanotubes (SWCNTs), the final properties strongly depend on the dispersion quality of these fillers. Various methods have been used to improve the dispersion of nanofillers; however, one of the most effective ways is to functionalize carbon nanotubes (CNTs) with covalent and noncovalent functional groups. In this work, the dispersion of SWCNTs in an epoxy system was studied by using surfactants, acid (COOH), and ester groups (PGE)‐modified CNTs. Rheological and scanning electron microscopy analysis showed that functionalization of CNTs helped in improving the dispersion of fillers in the epoxy matrix. Systems with surfactant modified SWCNTs (1 wt%) exhibited the highest storage modulus at low frequencies after 5‐min sonication. This behavior is associated to a stronger network of fillers as a result of a good dispersion. However, longer sonication times lowered the storage modulus, corresponding to a degradation of the tubes. The effect of the dispersion quality on mechanical properties was also studied using a three‐point bending set‐up. POLYM. COMPOS.,, 2012. © 2012 Society of Plastics Engineers     

Mechanical,thermal, and rheological properties of graphene‐based polypropylene nanocomposites prepared by melt mixing

In this article, we describe the fabrication by melt mixing of graphene‐polypropylene nanocomposites and present the effect of graphene addition on some selected properties of polypropylene (PP). The graphene nanosheets (GNs) used as nano‐reinforcing agents were obtained through chemical reduction of graphene oxide by hydrazine hydrate. GNs were characterized and successfully dispersed into PP matrix to produce PP/GNs nanocomposites. The effects of GNs content on thermal, mechanical, and rheological properties were reported, and the obtained results were discussed in terms of morphology and state of dispersion and distribution of the GNs within the polymer matrix. Characterization by scanning electron microscopy and X‐ray diffraction of the nanocomposites has shown a relatively good dispersion of GNs in the polymer matrix, with the presence of only few aggregates. Increasing GNs content resulted in a significant increase in both mechanical and thermal properties with only few percent of GNs loading. Rheological behavior of the PP/GNs nanocomposites showed a Maxwellian‐like behavior for low GNs concentrations and a viscoelastic solid‐like behavior for GNs content exceeding the concentration of the percolation threshold. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers