The Experts below are selected from a list of 4671 Experts worldwide ranked by ideXlab platform
Gert Heinrich - One of the best experts on this subject based on the ideXlab platform.
-
determination of phase specific localization of carbon black in ternary Rubber Blends a macroscopic approach by fourier transform infrared spectroscopy ftir
Polymer, 2018Co-Authors: Klaus Werner Stöckelhuber, Gert Heinrich, A D Sarma, Amit Das, Sven Wiesner, Anil K BhowmickAbstract:Abstract The phase specific localization of the reinforcing fillers like carbon black (CB), which has been known to influence the physical and mechanical performance of the Rubber Blends, can be determined by different characterization techniques, however, only for binary Rubber Blends. They have been failed so far when applied for more complicated systems like filled ternary Rubber Blends. In the present work we introduced a new technique using the attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) with germanium crystal for characterization of the specific localization of CB in a ternary Blend of solution styrene butadiene Rubber (SBR), butadiene Rubber (BR) and natural Rubber (NR). It is the first time we could follow the change of the amount of CB localized in each phase of this Blend along the mixing time. CB firstly is incorporated into the NR phase and then it obviously migrates from the NR phase to the SBR phase as a function of mixing time that corresponds very well with the theoretical prediction based on the Z-model using the surface tension values of the filler and Rubber Blend components. The interaction between CB and Rubber components can be qualitatively proved by the shift of the FTIR peak. Thermogravimetric analysis (TGA) was used to support the results obtained by the FTIR method. The study was further extended to follow the CB distribution in multi-step mixing.
-
effect of different ionic liquids on the dispersion and phase selective wetting of carbon nanotubes in Rubber Blends
Polymer, 2016Co-Authors: Amit Das, Klaus Werner Stöckelhuber, Sven Wiesner, Anil K Bhowmick, Suman Basak, M Tahir, Dieter Fischer, Uta Reuter, Gert HeinrichAbstract:Abstract The aim of this work was to study the effect of the ionic liquids (ILs) with respect to their anion type and the length of alkyl chain as dispersing and coupling agent in carbon nanotube (CNT) filled styrene butadiene Rubber (SBR)/natural Rubber (NR) Blends. We characterized the ILs by their surface tensions whereupon their different values explain the different compatibilities of ILs with the Rubber components and the filler. The wetting concept was further developed in order to experimentally characterize the effect of the Rubber-IL and CNT-IL compatibility on the selective wetting of CNTs in Rubber Blends. It was found that all the used ILs improved the dispersion of CNTs in Rubber Blends significantly. During the mixing process the IL layer pre-bound to the CNT surface was replaced mainly by the NR phase and, partly, by the SBR phase. Thus, ILs cannot be used as coupling agent in this Rubber Blend. For the ILs with surface tension similar to that of CNTs the filler was partly wetted by IL that imparts the mixture a high electrical conductivity directly after the mixing process. This high conductivity can be used for triggering the vulcanization of the Blend by means of the Joule heating. The preferential localization of ILs in the Rubber matrix - but not in Rubber-filler interphase - considerably influences the cross-link behavior of the vulcanizates and thus their final mechanical properties significantly.
-
modified and unmodified multiwalled carbon nanotubes in high performance solution styrene butadiene and butadiene Rubber Blends
Polymer, 2008Co-Authors: Klaus Werner Stöckelhuber, René Jurk, Marina Saphiannikova, J Fritzsche, H Lorenz, M Kluppel, Gert HeinrichAbstract:Abstract The outstanding properties of carbon nanotubes have generated scientific and technical interests in the development of nanotube-reinforced polymer composites. Therefore, we investigated a novel mixing approach for achieving a good dispersion of multiwalled carbon nanotubes (CNTs) in a Rubber Blend. In this approach the CNTs were incorporated into a 50:50 Blend of solution-styrene–butadiene Rubber and butadiene Rubber. First, the CNTs were predispersed in ethanol and then this CNT–alcohol suspension was mixed with the Rubber Blend at elevated temperature. The Rubber nanocomposites prepared by such method exhibit significantly enhanced physical properties already at very low nanotube concentrations. Additionally, we have analysed the dielectric and thermal properties of the compound. The high aspect ratio of the carbon nanotubes enabled the formation of a conductive percolating network in these composites at concentrations below 2 wt.%. In contrast to the electrical conduction behaviour, the thermal conductivity of the composites has not been influenced significantly by the presence of carbon nanotubes. Dynamic mechanical analysis indicates that the incorporation of CNTs affects the glass transition behaviour by reducing the height of the tan δ peak considerably. Above the glass transition temperature the storage modulus has been increased after incorporation of a small amount of CNTs. Finally, the ‘Payne effect’, an indication of filler–filler interactions, was observed at very low concentrations of CNT in the Rubber matrix.
S.m. Hosseini - One of the best experts on this subject based on the ideXlab platform.
-
preparation and electrochemical characterization of monovalent ion selective poly vinyl chloride Blend poly styrene co butadiene heterogeneous cation exchange membrane coated with poly methyl methacrylate
Separation Science and Technology, 2012Co-Authors: S.m. Hosseini, Sayed Siavash Madaeni, H Asiani, Asieh HeidariAbstract:In this research, polyvinylchloride/ styrene-butadiene-Rubber Blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. Poly methyl methacrylate (PMMA) was also employed as membrane surface modifier by emulsion polymerization technique to improve the membrane selectivity and anti-fouling property. The effect of used emulsion composition on properties of home-made membranes was studied. SOM images showed uniform particles distribution and relatively uniform surfaces for the membranes. Results revealed that surface modification of membrane led to decrease in water content, ion exchange capacity, and ionic permeability in composite membranes. Membrane potential, transport number, selectivity, ionic concentration, and membrane surface electrical resistance all were increased by the PMMA coating on membrane surface. Also, the results showed that decrease of (Methyl methacrylate (MMA): S...
-
preparation and characterization of ion selective polyvinyl chloride based heterogeneous cation exchange membrane modified by magnetic iron nickel oxide nanoparticles
Desalination, 2012Co-Authors: S.m. Hosseini, Sayed Siavash Madaeni, A.r. Heidari, A AmirimehrAbstract:Abstract In this research, polyvinylchloride/styrene–butadiene-Rubber Blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. Iron–nickel oxide (Fe2NiO4) nanoparticle was also employed as additive in membrane fabrication. The effect of additive concentration on properties of home-made membranes was studied. SOM images showed uniform particles distribution and relatively uniform surfaces for the membranes. The increase of Fe2NiO4 concentration in casting solution caused to decrease of membrane water content. Membrane ion exchange capacity initially was increased by additive increasing to 1 wt.% and then showed decreasing trend with higher additive content. Membrane potential, charge density, permselectivity and transport number were enhanced initially by increase of additive loading to 2 wt.% and then they began to decrease by more additive concentration. Membranes exhibited lower potential, selectivity and transport number for bivalent ions compared to monovalent ones. Membrane permeability, flux and conductivity were enhanced initially in monovalent ionic solution by increase in additive concentration to 0.5 wt.% and then began to decrease by more additive loading. Permeability was improved for bivalent ions with increase in additive concentration. Modified membranes showed higher permeability for bivalent ions compared to monovalent type.
-
preparation and characterization of polyvinyl chloride styrene butadiene Rubber Blend heterogeneous cation exchange membrane modified by potassium perchlorate
Desalination, 2011Co-Authors: S.m. Hosseini, Sayed Siavash Madaeni, A.r. Heidari, Abdolreza MoghadassiAbstract:Abstract In the current research, polyvinylchloride (PVC)/styrene-Butadiene-Rubber (SBR) Blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. Potassium perchlorate was also employed as an additive in membrane fabrication. The effect of additive concentration in the casting solution on physico-chemical properties of home-made membranes was studied. Sonication was used to help in appropriate dispersion of particles in the membranes matrix. SEM images showed uniform particles distribution and also relatively uniform surfaces for the membranes. Moreover, images revealed that addition of KClO4 in the casting solution led to an improvement in resin particles distribution in the membranes matrix. The increase of KClO4 loading in casting solution caused the increase of membranes water content. The ion exchange capacity, membrane potential, permselectivity and transport number of the membranes all were increased initially by the increase of additive concentration up to 8 wt.% and then they showed decreasing trend with higher additive content. Conversely, the ionic permeability and flux showed opposite trends. The areal electrical resistance of the membranes was initially enhanced with increase in additive concentration to 16 wt.% and then it began to decrease by more additive loading.
Akbar Shojaei - One of the best experts on this subject based on the ideXlab platform.
-
vulcanization kinetics and reversion behavior of natural Rubber styrene butadiene Rubber Blend filled with nanodiamond the role of sulfur curing system
European Polymer Journal, 2016Co-Authors: Sima Rabiei, Akbar ShojaeiAbstract:Abstract The effect of nanodiamond (ND) particles on the network structure and vulcanization kinetics of natural Rubber (NR)/styrene-butadiene Rubber (SBR) Blend vulcanized by three different curing systems, namely conventional (CV), semi-efficient (SEV) and efficient (EV), was investigated. The filler dispersion, crosslink density, curing kinetics and reversion behavior were fully studied. The state of ND dispersion in the Rubber matrix was investigated by the field emission scanning electron microscope (FESEM). Swelling experiments and tensile tests exhibited that upon incorporation of ND crosslink density of NR/SBR Blend was enhanced significantly due to the large surface area of nano filler developing high polymer-particle interactions. It was revealed that ND could also affect the curing behavior of the Blend regardless of the curing systems used, as it decreased the activation energies of induction period and vulcanization kinetics analyzed by isoconversional and model fitting methods. However, the higher influence of ND on the network structure and vulcanization kinetics was observed for SEV system. In addition, kinetics analysis by Han model revealed that in presence of ND the reversion behavior was improved considerably due to the promotion of more thermally stable crosslinks in the network.
-
reinforcing mechanisms of carbon nanotubes and high structure carbon black in natural Rubber styrene butadiene Rubber Blend prepared by mechanical mixing effect of bound Rubber
Polymer International, 2015Co-Authors: Morteza Ahmadi, Akbar ShojaeiAbstract:The reinforcing effect of high structure carbon black (HSCB) and multi-walled carbon nanotubes (MWCNTs) on natural Rubber/styrene-butadiene Rubber Blend processed using mechanical mixing was comparatively investigated. In-depth analysis by dynamic mechanical analysis, the Eggers − Schummer model and Medalia's relationship showed that HSCB aggregates provided large internal pores leading to significant immobilized macromolecules in filled Rubber. Additionally, a tubular immobilized Rubber layer with a thickness of 8 nm was estimated for the Rubber/MWCNT system based on dynamic mechanical analysis data. The mechanical performance of the HSCB filled Blend was higher than that of the MWCNT filled Blend at the same loading which was correlated to its higher bound Rubber content. Both bound Rubber content and filler anisotropy were found to govern the overall mechanical properties of Rubber/MWCNT composites. Stress softening was correlated with rupture energy suggesting hysteretic failure mechanisms in both MWCNT and HSCB filled Rubbers. © 2015 Society of Chemical Industry
-
analysis of structure properties relationship in nitrile butadiene Rubber phenolic resin organoclay ternary nanocomposites using simple model system
Polymers for Advanced Technologies, 2010Co-Authors: Akbar Shojaei, Morteza FaghihiAbstract:The present study deals with the structure–property relationship of organoclay (OC) filled nanocomposites based on Rubber Blend comprising of nitrile-butadiene Rubber (NBR) and phenolic resin (PH). To obtain a better insight into the characteristics of the NBR/PH/OC hybrid system, a simple model system consisting of NBR/OC nanocomposites is also taken into consideration. A series of NBR/OC and NBR/PH/OC nanocomposites containing a wide range of OC concentrations (2.5–30 phr) are prepared by using traditional open two-roll mill. Structural analysis performed by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) exhibits mixed exfoliated and intercalated morphology at low OC content, below 7.5 phr, and a well-ordered intercalated morphology at higher OC loading. It is shown that the dispersion of OC is also influenced by mixing time and order of mixing of components. Analysis of the cure characteristics, mechanical, and thermal properties of both the NBR/OC and NBR/PH/OC nanocomposites reveals that the OC is dispersed mainly in the NBR continuous phase, even though some is likely localized in the Rubber–resin interface. Copyright © 2009 John Wiley & Sons, Ltd.
Norzawani Yahya - One of the best experts on this subject based on the ideXlab platform.
-
radiation crosslinking of Rubber phase in poly vinyl chloride epoxidized natural Rubber Blend effect on mechanical properties
Polymer Testing, 2006Co-Authors: Chantara Thevy Ratnam, Sabariah Kamaruddin, Yaganaidu Sivachalam, Marina Talib, Norzawani YahyaAbstract:Abstract The effect of pre-irradiation of epoxidized natural Rubber (ENR 50) on the properties of 50/50 poly(vinyl chloride)/epoxidized natural Rubber Blend (PVC/ENR) was investigated. The ENR 50 was irradiated using a 3.0 MeV electron beam accelerator at a dose range of 10–100 kGy in air and at room temperature. The irradiated ENR 50 was then melt Blended with PVC using a Brabender Plasticorder Model PL2000 at 50 rpm, 150 °C for 15 min. The effect of electron beam irradiation of the ENR 50 on the 50/50 PVC/ENR Blend was studied by examining evidence from the torque–time curve, tensile strength, elongation at break, modulus, hardness, impact strength and gel fraction. The torque–time curves indicated that the irradiation dose has significant influence on the Blend homogeneity. An upward tend was observed for tensile strength, modulus, hardness, impact strength and gel fraction of the 50/50 PVC/ENR Blend with irradiation dose. Such observation indicate that irradiation of the ENR 50 phase contributes to the enhancement in PVC/ENR Blend properties.
Chantara Thevy Ratnam - One of the best experts on this subject based on the ideXlab platform.
-
nr epdm elastomeric Rubber Blend miscibility evaluation by two level fractional factorial design of experiment
THE 2014 UKM FST POSTGRADUATE COLLOQUIUM: Proceedings of the Universiti Kebangsaan Malaysia Faculty of Science and Technology 2014 Postgraduate Colloq, 2014Co-Authors: Chantara Thevy Ratnam, Jeefferie Abd Razak, Sahrim Ahmad, Mazlin Aida Mahamood, Juliana Yaakub, Noraiham MohamadAbstract:Fractional 25 two-level factorial design of experiment (DOE) was applied to systematically prepare the NR/EPDM Blend using Haake internal mixer set-up. The process model of Rubber Blend preparation that correlates the relationships between the mixer process input parameters and the output response of Blend compatibility was developed. Model analysis of variance (ANOVA) and model fitting through curve evaluation finalized the R2 of 99.60% with proposed parametric combination of A = 30/70 NR/EPDM Blend ratio; B = 70°C mixing temperature; C = 70 rpm of rotor speed; D = 5 minutes of mixing period and E = 1.30 phr EPDM-g-MAH compatibilizer addition, with overall 0.966 desirability. Model validation with small deviation at +2.09% confirmed the repeatability of the mixing strategy with valid maximum tensile strength output representing the Blend miscibility. Theoretical calculation of NR/EPDM Blend compatibility is also included and compared. In short, this study provides a brief insight on the utilization of DOE for experimental simplification and parameter inter-correlation studies, especially when dealing with multiple variables during elastomeric Rubber Blend preparation.
-
radiation crosslinking of Rubber phase in poly vinyl chloride epoxidized natural Rubber Blend effect on mechanical properties
Polymer Testing, 2006Co-Authors: Chantara Thevy Ratnam, Sabariah Kamaruddin, Yaganaidu Sivachalam, Marina Talib, Norzawani YahyaAbstract:Abstract The effect of pre-irradiation of epoxidized natural Rubber (ENR 50) on the properties of 50/50 poly(vinyl chloride)/epoxidized natural Rubber Blend (PVC/ENR) was investigated. The ENR 50 was irradiated using a 3.0 MeV electron beam accelerator at a dose range of 10–100 kGy in air and at room temperature. The irradiated ENR 50 was then melt Blended with PVC using a Brabender Plasticorder Model PL2000 at 50 rpm, 150 °C for 15 min. The effect of electron beam irradiation of the ENR 50 on the 50/50 PVC/ENR Blend was studied by examining evidence from the torque–time curve, tensile strength, elongation at break, modulus, hardness, impact strength and gel fraction. The torque–time curves indicated that the irradiation dose has significant influence on the Blend homogeneity. An upward tend was observed for tensile strength, modulus, hardness, impact strength and gel fraction of the 50/50 PVC/ENR Blend with irradiation dose. Such observation indicate that irradiation of the ENR 50 phase contributes to the enhancement in PVC/ENR Blend properties.
-
evidence of irradiation induced crosslinking in miscible Blends of poly vinyl chloride epoxidized natural Rubber in presence of trimethylolpropane triacrylate
Journal of Applied Polymer Science, 2001Co-Authors: Chantara Thevy Ratnam, M Nasir, A Baharin, Khairul ZamanAbstract:Electron-beam initiated crosslinking of a poly(vinyl chloride)/epoxidized natural Rubber Blend (PVC/ENR), which contained trimethylolpropane triacrylate (TMPTA), was carried out over a range of irradiation doses (20–200 kGy) and concentrations of TMPTA (1–5 phr). The gelation dose was determined by a method proposed by Charlesby. It was evident from the gelation dose, resilience, hysteresis, glass-transition temperature (Tg), IR spectroscopy, and scanning electron microscopy studies that the miscible PVC/ENR Blend underwent crosslinking by electron-beam irradiation. The acceleration of crosslinking by the TMPTA was further confirmed in this study. Agreement of the results with a theory relating the Tg with the distance between crosslinks provided further evidence of irradiation-induced crosslinking. The possible mechanism of crosslinking induced by the irradiation between PVC and ENR is also proposed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1914–1925, 2001
