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1.
《Polymer Composites》2017,38(2):396-403
A cationic gemini surfactant (N‐isopropyl‐N , N‐dimethyldodecan 1‐aminium bromide) was synthesized by quaternization reaction. The synthesized surfactant was characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. Modified Na–bentonite (organoclay) was obtained by the intercalation of a gemini surfactant between the layers of sodium bentonite and characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), FTIR, thermogravimetry–differential thermal analysis (TGA–DTA) and differential scanning calorimetry (DSC) techniques. The results of XRD, TEM, FTIR, TGA, and corresponding DSC analysis indicate that gemini surfactant has been successfully intercalated into the clay layers. Rubber‐based nanocomposites have been prepared by incorporating various concentration of organically modified bentonite on to natural rubber/styrene–butadiene rubber (NR/SBR) rubber blend (75/25) using two roll mill. Effect of organoclay content on XRD, curing, mechanical, and scanning electron microscopy (SEM) properties of the nanocomposites are investigated. The morphological study showed the intercalation of nanoclay in NR/SBR blend chain. It was found that the organoclay decrease the optimum and scorch time of the curing reaction, increase maximum torque and the curing rate, which was attributed to the further intercalation during vulcanization process. Mechanical properties such as tensile strength, modulus and elongation at break have improved. POLYM. COMPOS., 38:396–403, 2017. © 2015 Society of Plastics Engineers  相似文献   

2.
Organo‐montmorillonite/nitrile butadiene rubber (OMMT/NBR) nanocomposites were prepared by co‐coagulating process, and then were combined with rubber ingredient and vulcanized by traditional rubber mixing procedure. The SEM micrographs of the nanocomposites showed uniform dispersion of the OMMT particles in NBR. The ATR‐FTIR spectra illustrated the existence of montmorillonite in the nanocomposites. The XRD patterns further indicated the structure of nanocomposites, and confirmed an effective intercalation of NBR in the interlayer space of the OMMT. Moreover, the tensile strength and elongation at break of nanocomposites tended to increased rapidly with increasing OMMT loading, due to the reinforcing properties of OMMT to NBR. In addition, the TGA and DTA curves demonstrated the thermal performance of the nanocomposites enhanced. Furthermore, the addition of OMMT accelerated the vulcanization process. POLYM. COMPOS., 34:1809–1815, 2013. © 2013 Society of Plastics Engineers  相似文献   

3.
In the present work, the influences of different silane coupling agents (SCA) on the rheological behaviors of Bent/NBR nanocomposites during the curing process were investigated. The nanocomposites were prepared with a green method which is simple and free of organic solvents. The dispersion state and filler–polymer interfaces were analyzed with XRD, TEM, and SEM while rheological behaviors of the nanocomposites were explored with a rubber processing analyzer (RPA). (3‐Mercaptopropyl)trimethoxysilane (MPTMS) and bis[3‐(triethoxysilyl)propyl] tetrasulfide (TESPT) both improved the dispersion state of bentonite in the matrixes significantly. MPTMS increased the crosslinking density by forming single sulfur bonds while TESPT worked as a plasticizer and delayed the formation of crosslinking during curing process. [3‐(2‐Aminoethylamino)propyl]triethoxysilane (AEAPTMS) led to reversible filler–rubber interactions, which was the main reason for the low elastic torque of the vulcanized nanocomposites. J. VINYL ADDIT. TECHNOL., 25:236–242, 2019. © 2018 Society of Plastics Engineers  相似文献   

4.
Polymer blending coupled with nanofillers has been widely accepted as one of the cheaper methods to develop high‐performance polymeric materials for various applications. In the present work, dodecyl sulfate intercalated Mg? Al‐based layered double hydroxide (DS‐LDH) was used as nanofiller in the synthesis of polyurethane blended with nitrile butadiene rubber (PU/NBR; 1:1 w/w) nanocomposites, which were subsequently characterized. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the partial dispersion of Mg? Al layers in PU/NBR blends at lower filler content followed by aggregation at higher filler loading. In comparison to the neat PU/NBR blend, the tensile strength (156%) and elongation at break (21%) show maximum improvement for 1 wt% filler loading. The storage and loss moduli, thermal stability and limiting oxygen index of the nanocomposites are higher compared to the neat PU/NBR blend. Glass transition temperature and swelling measurements increase up to 3 wt% DS‐LDH loading in PU/NBR compared to either neat PU/NBR or its other corresponding nanocomposites. XRD and TEM analyses indicate the partial distribution of DS‐LDH in PU/NBR blends suggesting the formation of partially exfoliated nanocomposites. The improvements in mechanical, thermal and flame retardancy properties are much greater compared to the neat blend confirming the formation of high‐performance polymer nanocomposites. Copyright © 2009 Society of Chemical Industry  相似文献   

5.
Well‐dispersed poly(methyl methacrylate) (PMMA)–bentonite clay composite was synthesized by emulsion polymerization using methyl methacrylate (MMA) monomer and 3% sodium carbonate treated bentonite clay. The composite lost its transparency normally encountered with the neat PMMA. The composite was characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), vicat softening point (VSP), dynamic mechanical thermal analysis (DMTA), and tensile studies. The morphology was investigated by scanning electron microscopy (SEM) and atomic forced microscopy (AFM) as well. The crystallography was studied to estimate the changes in crystallographic planes by X‐ray diffraction (XRD) analysis. The particle size distribution was compared amongst neat bentonite clay, neat PMMA and the composite. The FTIR spectra reveal the fact that no new primary valence bond is formed between the clay and PMMA. The thermal stability of the composite is significantly improved, as indicated by the TGA and VSP studies. A substantial increase in glass transition temperature (Tg) approximately, 10°C was recorded from the DMTA as both the storage modulus and tan δ values underwent inflexion at higher temperatures in case of the composite compared with the pristine PMMA. The XRD pattern indicates increase in basal “d” spacing for the composite. The morphology from both the SEM and AFM is quite supportive to well‐dispersed exfoliation. The incorporation of nanosized activated clay particles in PMMA during its in situ polymerization from MMA led to the formation of nanocomposites. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers  相似文献   

6.
Several kinds of (hydrogenated) nitrile elastomer ((H)NBR) compounds were prepared by melt compounding of rubbers with carbon nanotubes. Transmission electron microscopy (TEM) showed that the exfoliation degree of nanotubes was high. Multiwalled carbon nanotubes (MWCNT) were either neat or modified by hydroxyl or carboxyl groups. Morphology was also characterized by scanning electron microscopy (SEM). The cure kinetics of (H)NBR and modified multiwalled carbon nanotubes ((m‐)MWCNT/(H)NBR) nanocomposites was studied. It was found that the apparent curing and over‐cure activation energies (EA and EA,1) increased with the increasing amount of (m‐)MWCNT. There was a less obvious change in the apparent orders of curing reactions. The results of n‐th order and autocatalytic kinetic model showed that any studied content of (m‐)MWCNT could increase effective thermal conductivity, but decreased the vulcanization rate of (m‐)MWCNT/(H)NBR nanocomposites. Finally, the effect of (m‐)MWCNT content and functionalization on tensile mechanical properties was presented. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers  相似文献   

7.
Antimony doped tin oxide (ATO) nanoparticles were used as nanofillers to improve mechanical properties of UV‐cured polyester–acrylate films. To improve the dispersion of ATO nanoparticles in the polyester–acrylate resin matrix and to strengthen interfacial interactions between ATO nanoparticles and the resin matrix ATO nanoparticles were first organically modified with 3‐methacryloxypropyltrimethoxysilane (MPS). The modification of ATO nanoparticles with MPS was confirmed by FTIR spectroscopy and thermogravimetric analysis (TGA). UV‐curing behaviors of the nanocomposites films were investigated by FTIR spectroscopy. Compared with the film with neat ATO nanoparticles, the film with the same amount of MPS‐modified ATO nanoparticles showed slightly higher UV‐curing rate and final conversion. The mechanical properties of the nanocomposites films were measured by universal testing machine. The MPS‐modified ATO nanoparticles could improve considerably the mechanical properties of the UV‐cured polyester–acrylate nanocomposites films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

8.
Rubber compounds based on acrylonitrile butadiene rubber (NBR) containing organically modified layered double hydroxides (LDHs) were prepared using peroxide as a curing agent. The LDHs intercalated by organic compounds including sodium styrene sulfonate (SSS) and sodium dodecylbenzene sulfonate (SDBS) were investigated using thermogravimetric analysis (TGA) and X‐ray diffraction (XRD) while the unmodified LDHs were used as contrast. Experimental results from TGA and XRD showed that both SSS‐ and SDBS‐intercalated LDHs were successfully obtained. The morphology of the LDH composites was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and XRD. The chemical structure of NBR/LDHs compounds were measured by Fourier transform infrared spectrum. The thermal properties were measured by TGA and differential scanning calorimetry. Other properties such as mechanical and swelling properties were also investigated. The results showed that a chemical bonding between organically modified LDHs and rubber matrix through SSS was built during vulcanization, which leads to improved interfacial strength of the cured compound. A high‐performance acrylonitrile butadiene rubber/SSS‐modified LDH compound, which has two times higher tensile strength than cured pure rubber without significant loss of elongation, was obtained. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

9.
In the present study, new functional poly(amide‐imide)/organoclay nanocomposite films were successfully fabricated through the solution intercalation technique. New poly(amide‐imide) (PAI) containing glycine was synthesized via solution polycondensation of 1,1',3,3'‐tetraoxo(5,5'‐biisoindoline‐2,2'‐diyl)diacetic acid with 4,4′‐diaminodiphenylsulfone. The synthesized PAI was characterized by 1H NMR, Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography, elemental analysis and inherent viscosity. Then, PAI/organoclay nanocomposite films containing 4 and 8 wt% of organoclay were prepared via solution intercalation through blending of organoclay 30B with the PAI solution. The nanostructures and properties of the PAI/organoclay were investigated using FTIR spectroscopy, XRD, transmission electron microscopy (TEM), TGA, DSC and microscale combustion calorimetry. XRD and TEM revealed the good dispersion of organoclay in the polymer matrix. TGA indicated that the addition of organoclay into the PAI matrix increases the thermal decomposition temperatures and char yields of the nanocomposites. Organoclay shows a positive effect in improving the flame retardancy of the PAI, reflecting the decrease in heat release rate, the total heat release and the heat release capacity of the PAI nanocomposites, while the thermal stability of the PAI nanocomposites only increased slightly compared with the neat polymer. © 2013 Society of Chemical Industry  相似文献   

10.
A benzoxazine monomer (VB‐a) containing an allyl groups was synthesized through the Mannich condensation of bisphenol A, formaldehyde, and allylamine (bisphenol‐A and allylamine as VB‐a). This monomer was then reacted with polyhedral oligomeric silsesquioxane (POSS) through hydrosilylation, followed by thermal curing to form poly(VB‐a)/POSS hybrid nanocomposites. The curing behavior of the nanocomposites was monitored using Fourier transform infrared spectroscopy (FTIR), and their thermal and morphological properties were investigated through thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and scanning electron microscopy. DMA revealed that the glass transition temperatures of the poly(VB‐a)/POSS nanocomposites were higher than that of the pristine poly(VB‐a), presumably because the POSS cages effectively hindered the motion of the polymer chains. TGA confirmed that the thermal degradation temperatures and char yields of the polybenzoxazines increased after incorporation of the POSS moieties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

11.
In this study, multi‐walled carbon nanotubes (MWCNTs) and boron nitride (BN) were functionalized with cetyltrimethylammonium bromide (CTAB) at both pH 5.5 and pH 11. These MWCNT‐CTAB and BN‐CTAB particles used to prepare the composites were dispersed in a bisphenol A (DGEBA)‐type epoxy resin (ER) system at room temperature. The TGA analysis showed that the BN composite can significantly improve the thermal stability of neat ER at temperatures above 400 °C. The curing degrees of the nanocomposites were calculated to be approximately the same values as neat ER using the Beer–Lambert law from FTIR spectra. The best electrical conductivity of the composites obtained was 3.10 × 10−3 S/cm for ER/MWCNT‐CTAB (pH 5.5). The surface hardness, Young's modulus, and tensile strength of the composites were examined. The surface hardness values of the ER/MWCNT‐CTAB composites were higher than those of the other composites. The composite morphology was characterized using X‐ray diffraction (XRD) and scanning electron microscopy (SEM). POLYM. COMPOS., 37:3423–3432, 2016. © 2015 Society of Plastics Engineers  相似文献   

12.
A tough and highly flexible hyperbranched epoxy and poly(amido‐amine) modified bentonite based thermosetting nanocomposite was demonstrated. The FTIR, XRD, and TGA analyses confirmed the modification of bentonite. The formation of partially exfoliated structure of the nanocomposite with good physicochemical interactions among the hyperbranched epoxy, poly(amido‐amine) hardener and modified clay was investigated by the FTIR, XRD, SEM, and TEM analyses. Significant improvements of 750% toughness, 300% elongation at break, 50% tensile strength, 300% modulus, and 250% adhesive strength of the pristine epoxy were achieved by the formation of nanocomposites with 3 wt % of modified clay. The experimental modulus values of the nanocomposites were compared with three theoretical models to account the interactions between filler and matrix. Thus, the studied epoxy nanocomposite has great potential to be used as an advanced epoxy thermoset. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40327.  相似文献   

13.
Mg–Al layered double hydroxide (LDH)/Ethylene vinyl acetate (EVA‐28) nanocomposites were prepared through solution intercalation method using organically modified layered double hydroxide (DS‐LDH). DS‐LDH was made by the intercalation of sodium dodecyl sulfate (SDS) ion. The structure of DS‐LDH and its nanocomposites with EVA‐28 was determined by X‐ray diffraction (XRD) and transmission electron microscope (TEM) analysis. XRD analysis shows that the original peak of DS‐LDH shifted to lower 2θ range and supports the formation of intercalated nanocomposites while, TEM micrograph shows the presence of partially exfoliated LDH nanolayers in addition to orderly stacked LDH crystallites in the polymer matrix. The presence of LDH in the nanocomposites has been confirmed by Fourier transform infrared (FTIR) analysis. The mechanical properties show significant improvement for the nanocomposite with respect to neat EVA‐28. Thermogravimetric (TGA) analysis shows that thermal stability of the nanocomposites is higher than that of EVA‐28. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1845–1851, 2007  相似文献   

14.
Polypropylene/organic‐montmorillonite (PP/OMMT) nanocomposites were prepared via a solid‐phase PP graft (TMPP) with a higher grafting level as the compatibilizer. The effects of the compatibilizer on the structure and properties of PP/OMMT nanocomposites were investigated. The structure of the nanocomposites were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that when the weight ratio of TMPP and OMMT is greater than 1:1, the OMMT can be dispersed in PP matrix uniformly at the nanoscale. The mechanical properties of the nanocomposites reached a maximum when the weight ratio of TMPP and OMMT is 1:1, although more uniform dispersion was achieved at a higher content of TMPP. The mechanical properties of the nanocomposites decrease with the content of TMPP. The crystallization behavior, dynamic rheological property, and thermal stability of the nanocomposites were investigated by differential scanning calorimetry (DSC), dynamic rheological analysis, and thermal gravimetric analysis (TGA), respectively. Due to the synergistic effects of TMPP and OMMT on the crystallization of PP, the crystallization peak temperature of the nanocomposites increased remarkably compared with that of the neat PP. TMPP shows β‐phase nucleating ability and OMMT promotes the development of β‐phase crystallite. The nanocomposites show restricted melt flow and enhanced temperature sensitivity compared with the neat PP. The thermal stability of the nanocomposites is obviously improved compared with that of the neat PP. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers.  相似文献   

15.
Nanocomposites of bentonite with polyaniline (PANI), poly(methacrylic acid) (PMAA), and poly(aniline‐co‐methacrylic acid) (PANI‐co‐PMAA) were prepared by in situ intercalative polymerization technique. The nanocomposites were characterized by FTIR and UV–visible spectroscopies, XRD, SEM, TEM, as well as TG‐DTA studies. The in situ intercalative polymerization of PANI, PMAA, and PANI‐co‐PMAA within bentonite layers was confirmed by FTIR, XRD, SEM, as well as TEM studies. XRD confirmed the intercalation of polymers and copolymer in bentonite. The average particle size of the nanocomposites was found to be in the range of 250–500 nm. The thermal stability was found be the highest for PANI‐co‐PMAA‐bentonite. The swelling behavior studies suggest that these nanocomposites hold potential for their utilization in absorption of toxic materials from waste water. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3299–3306, 2007  相似文献   

16.
A novel type of polybenzoxazine (PB‐m)/clay nanocomposites were prepared from 2‐bis (3‐methyl‐3,4‐dihydro‐2H‐1,3‐benzoxazinyl) propane (B‐m) and di‐methyl, di‐octadecyl ammonium chloride (DODMAC)‐modified clay. Surface properties and thermal stability of the PB‐m/clay nanocomposites were characterized by contact angle measurement and thermogravimetry (TGA), respectively. It was found that the PB‐m/clay nanocomposites possess the lowest surface free energy (15.27 mJ/m2) after 8 h curing at 210°C, which is even lower than that of poly (tetrafluoroethylene) (21.0 mJ/m2), and the presence of the clay in the B‐m PB‐m matrix enhances the stability of the surface energy at 210°C. FTIR results show that the intercalated structures of PB‐m/clay nanocomposites have no influence on the hydrogen‐bonding network of the PB‐m during curing. Combining with the results of atomic force microscope, it can be concluded that the stability of surface energies of the PB‐m/clay nanocomposites is mainly affected by the migration and masking of clay. Also, TGA results show that the addition of clay improves the thermal stability of PB‐m. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers  相似文献   

17.
A novel organically modified montmorillonite (OMMT) based on a bifunctional organic modifier‐12‐aminolauric acid (ALA) was synthesized. Polylactide (PLA) nanocomposites with this new and traditional OMMT were prepared by solution casting method. The effects of the organic modifiers on structure, morphology and thermal properties of PLA nanocomposites have been investigated using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The results indicate that ALA has distinct effects on the dispersion of MMT platelets into the PLA matrix, where partial exfoliated as well as intercalated structures have been obtained, when compared with ordinary modifier, cetyltrimethyl ammonium bromide (CTAB). TGA data verifies that PLA nanocomposites with ALA‐MMT organoclay display enhanced thermal stability. The optimal clay loading of ALA‐MMT occurs at 3%wt, leading to the best compromise between clay dispersion and thermal properties. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers  相似文献   

18.
Soybean oil‐based polymer nanocomposites were synthesized from acrylated epoxidized soybean oil (AESO) combined with styrene monomer and montmorillonite (MMT) clay by using in situ free radical polymerization reaction. Special attention was paid to the modification of MMT clay, which was carried out by methacryl‐functionalized and quaternized derivative of methyl oleate intercalant. It was synthesized from olive oil triglyceride, as a renewable intercalant. The resultant nanocomposites were characterized by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of increased nanofiller loading in thermal and mechanical properties of the nanocomposites was investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The nanocomposites exhibited improved thermal and dynamic mechanical properties compared with neat acrylated epoxidized soybean oil based polymer matrix. The desired exfoliated nanocomposite structure was achieved when the OrgMMT loading was 1 and 2 wt % whereas partially exfoliated nanocomposite was obtained in 3 wt % loading. It was found that about 400 and 500% increments in storage modulus at glass transition and rubbery regions, respectively were achieved at 2 wt % clay loading compared to neat polymer matrix while the lowest thermal degradation rate was gained by introducing 3 wt % clay loading. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2031–2041, 2013  相似文献   

19.
Carbon nanofillers like nanotubes and nanofibers have been used to reinforce various epoxy systems. The incorporation of carbon nanofillers into a thermosetting epoxy system enhanced the thermal and mechanical properties of the epoxy system. The best performance of an epoxy nanocomposite system with carbon nanofillers would be resulted from the homogeneous dispersion of the nanofillers and strong interfacial adhesion between the epoxy matrix and the nanofillers. Therefore, amine‐functionalization of carbon nanofibers (CNFs) and multiwalled carbon nanotubes (MWNTs) was carried out via treating them with 4‐aminobenzoic acid in polyphosphoric acid. FTIR spectroscopy, XPS, TGA, and FE‐SEM analyses confirmed that the functionalization was successful. Curing behavior and thermo‐physical properties of the nanocomposites comprising the pristine or functionalized carbon nanofillers were investigated and compared with each other. Fractured surfaces of the nanocomposites were investigated by FE‐SEM. The functionalized MWNTs induced stronger interfacial adhesion than the functionalized CNFs and resulted in considerable improvement in the physical properties of the epoxy nanocomposites. POLYM. COMPOS., 31:1449–1456, 2010. © 2009 Society of Plastics Engineers  相似文献   

20.
Exfoliated polypropylene (PP)/layered double hydroxide (LDH) nanocomposites have been successfully synthesized via melt‐intercalation. Their structure, thermal properties, and photo‐oxidative behavior have been characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA), X‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectrum. TGA and DMA data show that the PP/LDH nanocomposites have enhanced thermal stability compared with virgin PP and corresponding PP/montmorillonites (MMT) nanocomposites, especially in high temperature range during the thermal decomposition of the samples. XPS and FTIR results give positive evidence that the photo‐oxidation mechanism of PP in the PP/LDH materials is not modified compared with that of virgin PP. However, photo‐oxidation rate of PP/LDH materials is much lower than that of PP and PP/MMT samples, indicating that the PP/LDH nanocomposites have better UV‐stability. POLYM. ENG. SCI. 46:1153–1159, 2006. © 2006 Society of Plastics Engineers  相似文献   

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