NR/SBR composites reinforced with organically functionalized MWCNTs: simultaneous improvement of tensile strength and elongation and enhanced thermal stability

2016 ◽  
Vol 36 (8) ◽  
pp. 813-818 ◽  
Author(s):  
Minghua Li ◽  
Weixiao Tu ◽  
Xinfeng Chen ◽  
Huihui Wang ◽  
Jinyang Chen

Abstract Butyl acrylate-α-methyl methacrylate-glycidyl methacrylate (BA-MMA-GMA) terpolymer was successfully grafted onto carbon nanotubes (CNTs) via a facile grafting functionalization approach, affording an organically functionalized multiwalled CNTs (O-MWCNTs), which show improved mechanical and thermal properties in natural rubber/styrene-butadiene rubber (NR/SBR) composites. Under optimized conditions, the result of elongation at break of NR/SBR composites combined with 1.5 parts per hundred rubber (phr) O-MWCNTs is 450% compared to 376% of pristine NR/SBR composites, which is proportional to tensile strength due to the mixed O-MWCNTs in the rubber matrix. Transmission electron microscopy study shows that O-MWCNTs (1.5 phr) can disperse uniformly in NR/SBR/O-MWCNT composites. A scanning electron microscopy study on the fractured surface morphology of the optimized composites reveals that a BA-MMA-GMA terpolymer can interact with the rubber matrix strongly. The decreased height of the maximum tanδ peak shows that O-MWCNTs can reduce the heat buildup and damping capability of NR/SBR/O-MWCNT composites. The largest enhancement observed in the thermal degradation curves of composites is, for the first time, about 70°C, which can be attributed to enhanced interfacial interaction between MWCNTs and the rubber matrix.

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
R. Rajasekar ◽  
Gert Heinrich ◽  
Amit Das ◽  
Chapal Kumar Das

The significant factor that determines the improvement of properties in rubber by the incorporation of nanoclay is its distribution in the rubber matrix. The simple mixing of nonpolar rubber and organically modified nanoclay will not contribute for the good dispersion of nanofiller in the rubbery matrix. Hence a polar rubber like epoxidized natural rubber (ENR) can be used as a compatibilizer in order to obtain a better dispersion of the nanoclay in the matrix polymer. Epoxidized natural rubber and organically modified nanoclay composites (EC) were prepared by solution mixing. The nanoclay employed in this study is Cloisite 20A. The obtained nanocomposites were incorporated in styrene butadiene-rubber (SBR) compounds with sulphur as a curing agent. The morphology observed through X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) shows that the nanoclay is highly intercalated in ENR, and further incorporation of EC in SBR matrix leads to partial exfoliation of the nanoclay. Dynamic mechanical thermal analysis showed an increase in storage modulus and lesser damping characteristics for the compounds containing EC loading in SBR matrix. In addition, these compounds showed improvement in the mechanical properties.


2011 ◽  
Vol 695 ◽  
pp. 332-335 ◽  
Author(s):  
Anyaporn Boonmahitthisud ◽  
Zheng Hua Song

In this study, rubber blend of natural rubber (NR) and styrene butadiene rubber (SBR) at 80/20 NR/SBR was reinforced with nanosilica (nSiO2) and polystyrene-encapsulated nanosilica (PS-nSiO2) in the latex state. The latex of PS-nSiO2 was synthesized by in situ differential microemulsion polymerization using sodium dodecyl sulfate and azobisisobutyronitrile as the surfactant and initiator, respectively. The nanoparticles at the amount of 0.1, 0.2, 0.3 and 0.4 parts per hundred of rubber (based on dry weight of nSiO2) were dispersed in the rubber blend compound and subsequently cured at 80°C for 3 h to prepare rubber nanocomposites. Using this technique, nanoparticles could be well dispersed in the rubber matrix. The influences of the nSiO2 and PS-nSiO2 on the mechanical and thermal properties of the resulting nanocomposites were quantified and compared. It is found that the tensile properties and thermal stability of the rubber blends were improved with the appropriate amounts of the nanofillers. However, the PS-nSiO2 exhibited reinforcing efficiency superior to nSiO2 with the same nSiO2 content due to the stronger rubber-filler interfacial adhesion.


2017 ◽  
Vol 46 (3) ◽  
pp. 161-171 ◽  
Author(s):  
Salwa H. El-Sabbagh ◽  
Doaa Samir Mahmoud ◽  
Nivin M. Ahmed ◽  
A.A. Ward ◽  
Magdy Wadid Sabaa

Purpose This paper aims to study the role of organobentonite (OB) as a filler to improve the mechanical strength of styrene butadiene rubber (SBR). Organoclay was first prepared by modifying bentonite with different concentrations of N-cetyl-N, N, N-triethyl ammonium bromide. A series of SBR composites reinforced with OB were prepared using master-batch method. Design/methodology/approach The curing characteristics, mechanical properties, thermal behavior, dielectric properties and morphology of SBR/OB composites were investigated. Findings The elastic modulus and tensile strength of composites were increased by inclusion of OB, while the elongation at break was decreased, due to the increase in the degree of cross-linking density. Thermal gravimetric analysis revealed an improvement in the thermal stability of the composite containing 0.5 cation exchange capacity (CEC) OB, while the scanning electron micrographs confirmed more homogenous distribution of 0.5CEC OB in the rubber matrix. Also, SBR/0.5CEC OB showed low relative permittivity and electrical insulating properties. Research limitations/implications Bentonite has been recognized as a potentially useful filler in polymer matrix composites because of their high swelling capacity and plate morphology. Practical implications OB improves the cured rubber by increasing the tensile strength and the stiffness of the vulcanizate. Social implications Using cheap clay in rubber industry lead to production of low cost products with high efficiency. Originality/value The clay represents a convenient source because of their environmental compatibility. The low cost and easy availability make the modified clay used as fillers in rubber matrices, and the resultant composites can be applied in variety industrial of applications such as automobile industries, shoe outsoles, packaging materials and construction engineering.


2019 ◽  
Vol 107 (8) ◽  
pp. 737-753
Author(s):  
Hanan M. Eyssa ◽  
Wael S. Mohamed ◽  
Mai M. El-Zayat

Abstract In this work, nanosilica and micro carbon black (CB) as a fillers were used to improve the properties of styrene butadiene rubber/natural rubber blends (SBR/NR) crosslinked by γ radiation. Nanosilica was prepared from silica sand and used as eco-friendly material. These composites were characterized by field emission scanning electron microscopy (FESEM) and the measurements of the physic-mechanical and thermal properties were measured. Field emission scanning electron microscopy showed that the composites reinforced by nanosilica and the measurements of the CB are uniformly dispersed in the blends matrix. The results showed that the physico-mechanical and thermal properties were improved indicating a good interaction between the fillers and rubber matrix. The volume fraction measurements confirmed the formation of crosslinking network structure. Meanwhile, the reinforcement of SBR/NR blend loaded with nanosilica showed improved mechanical than blend loaded with both the nanosilica/carbon black and the CB alone. The highest enhancement was obtained for the three fillers by using a concentration of 35 phr at a dose of 150 kGy of γ-irradiation. Thermogravimetric analysis (TGA) indicated that the thermal stability of SBR/NR blend reinforced by nanosilica is higher than those blends reinforced with combined filler the silica. It was also found that the irradiated SBR/NR nanocomposites were more stable than the un-irradiated ones.


2020 ◽  
pp. 096739112090288
Author(s):  
Sun-Mou Lai ◽  
Yun-Lan Chu ◽  
Yu Ting Chiu ◽  
Ming-Chi Chang ◽  
Tung-Yuan Hsieh ◽  
...  

Only a few works focus on the use of commercial pyrolysis carbon black (PCB) to replace with commodity carbon black in terms of increasing environmental awareness. In this work, a commercial PCB (ET (Enrestec) black) from waste tires was compared with N660 carbon black in styrene–butadiene rubber (SBR) compounds using standard American Society for Testing and Materials recipes. Particle aggregate size, composition, and surface functionality of ET black and N660 were analyzed through light scattering, energy-dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy, respectively. Higher compound viscosity and aggregation power for ET black filler in the rubber matrix was observed. A progressive decrement of approximately 20% in M300 from 15.2 MPa for N660-filled SBR to 12.4 MPa for ET black-filled SBR with increasing ET black ratio in the fillers was clearly observed. ET black could potentially replace 20% in N660 without much influence for SBR compounds in terms of tensile strength. The effect of ET black content on the tear strength was less marginal than the tensile strength. However, with increasing the ET black content, the abrasion resistance index progressively decreased. Thus, it was quite beneficial to consider the merit of PCB in terms of the applications required for tearing resistance. This paves the way for the opportunities to expand further commercial application of PCB from waste tires in the light of environmental awareness.


2003 ◽  
Vol 76 (4) ◽  
pp. 860-875 ◽  
Author(s):  
Susmita Sadhu ◽  
Anil K. Bhowmick

Abstract Polymer nanocomposite is one of the highly discussed research topics in recent time. In this paper, we have reported the preparation and the properties of different nanoclays based on sodium montmorillonite, bentonite and potassium montmorillonite and organic amines of varying chain lengths, and Styrene Butadiene Rubber (SBR)-clay nanocomposites. The clays and the rubber nanocomposites have been characterized with the help of Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). X-ray results suggest that the intergallery distance is increased by incorporation of various amines. There is a great improvement in mechanical properties like tensile strength, elongation at break, modulus, work to break, and hysteresis on incorporation of nanoclay in SBR. TEM photographs show exfoliation of the clays in rubber to 5–10 nm range. The X-ray diffraction peak observed in the range of 3°– 10° for the control and the modified clays also disappears in rubber nanocomposites. Increasing chain length of clay modifiers and loading and nature of clays affect the mechanical and thermal properties significantly.


Author(s):  
Julie A. Martini ◽  
Robert H. Doremus

Tracy and Doremus have demonstrated chemical bonding between bone and hydroxylapatite with transmission electron microscopy. Now researchers ponder how to improve upon this bond in turn improving the life expectancy and biocompatibility of implantable orthopedic devices.This report focuses on a study of the- chemical influences on the interfacial integrity and strength. Pure hydroxylapatite (HAP), magnesium doped HAP, strontium doped HAP, bioglass and medical grade titanium cylinders were implanted into the tibial cortices of New Zealand white rabbits. After 12 weeks, the implants were retrieved for a scanning electron microscopy study coupled with energy dispersive spectroscopy.Following sacrifice and careful retrieval, the samples were dehydrated through a graduated series starting with 50% ethanol and continuing through 60, 70, 80, 90, 95, and 100% ethanol over a period of two days. The samples were embedded in LR White. Again a graduated series was used with solutions of 50, 75 and 100% LR White diluted in ethanol.


Author(s):  
J.G. Wen ◽  
K.K. Fung

Bi-based superconducting phases have been found to be members of a structural series represented by Bi2Sr2Can−1Cun−1On+4, n=1,2,3, and are referred to as 2201, 2212, 2223 phases. All these phases are incommensurate modulated structures. The super space groups are P2/b, NBbmb 2201, 2212 phases respectively. Pb-doped ceramic samples and single crystals and Y-doped single crystals have been studied by transmission electron microscopy.Modulated structures of all Bi-based superconducting phases are in b-c plane, therefore, it is the best way to determine modulated structure and c parameter in diffraction pattern. FIG. 1,2,3 show diffraction patterns of three kinds of modulations in Pb-doped ceramic samples. Energy dispersive X-ray analysis (EDAX) confirms the presence of Pb in the three modulated structures. Parameters c are 3 0.06, 38.29, 30.24Å, ie 2212, 2223, 2212 phases for FIG. 1,2,3 respectively. Their average space groups are all Bbmb.


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