The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform
Jose Savio Melo - One of the best experts on this subject based on the ideXlab platform.
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network density tailored standalone flexible Fluorocarbon Elastomer nanocarbon black chemiresistors for 2 propanone field detection
Sensors and Actuators B-chemical, 2018Co-Authors: R K Mondal, Jitendra Kumar, K A Dubey, Y K Bhardwaj, Jose Savio MeloAbstract:Abstract 2-propanone is a commonly-used chemical and is a biomarker of diabetic ketoacidosis. Herein, the development of a novel stand-alone chemiresistive sensor with high sensitivity and selectivity for 2-propanone is reported. Fluorocarbon Elastomer (FCE)/nanocarbon black (NCB) conducting composites based chemiresistors with different crosslinking densities were synthesized via melt compounding followed by radiation crosslinking. Conducting composites in different parts of the percolation profile were chosen to establish the dependence of 2-propanone sensing response on the conducting network and the radiation cross-linked network. The chemiresistor showed a highly selective response for 2-propanone whereas a considerably lower response was noted for benzene, toluene, xylene, ethanol, methanol and water. The sensing response had a strong correlation with the FCE-analyte interaction parameter (χ12).
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Network density tailored standalone-flexible Fluorocarbon Elastomer/nanocarbon black chemiresistors for 2-propanone field detection
Sensors and Actuators B-chemical, 2018Co-Authors: R K Mondal, Jitendra Kumar, K A Dubey, Y K Bhardwaj, Jose Savio Melo, Lalit VarshneyAbstract:Abstract 2-propanone is a commonly-used chemical and is a biomarker of diabetic ketoacidosis. Herein, the development of a novel stand-alone chemiresistive sensor with high sensitivity and selectivity for 2-propanone is reported. Fluorocarbon Elastomer (FCE)/nanocarbon black (NCB) conducting composites based chemiresistors with different crosslinking densities were synthesized via melt compounding followed by radiation crosslinking. Conducting composites in different parts of the percolation profile were chosen to establish the dependence of 2-propanone sensing response on the conducting network and the radiation cross-linked network. The chemiresistor showed a highly selective response for 2-propanone whereas a considerably lower response was noted for benzene, toluene, xylene, ethanol, methanol and water. The sensing response had a strong correlation with the FCE-analyte interaction parameter (χ12).
A. K. Bhowmick - One of the best experts on this subject based on the ideXlab platform.
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Novel nanostructured polyamide 6/fluoroElastomer thermoplastic Elastomeric blends: Influence of interaction and morphology on physical properties
Polymer, 2013Co-Authors: Shib Shankar Banerjee, A. K. BhowmickAbstract:Abstract Novel polyamide 6 (PA6)/fluoroElastomer nanostructured thermoplastic Elastomeric blends were developed in the present work. The influence of interaction between the components and morphology on physical properties of the blends was analyzed. Scanning electron microscopy and atomic force microscopy studies, solubility and theoretical analysis of complex modulus clearly indicated that PA6 was the continuous matrix in which Fluorocarbon Elastomer was present in nanoscale. Low torque ratio (0.34) of rubber/plastic, high mixing speed and long mixing time had an important role in developing the nanostructured morphology of the blend. Tensile strength of the thermoplastic Elastomer was about 39.0 MPa which was much higher than that reported earlier and showed significant improvement with increasing PA6 content. Large shifting of the glass transition temperature of the rubber and the plastic phases towards the lower temperature compared to those pristine polymers was also observed. The above properties were explained with the help of interaction between the components and morphology.
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Morphology, mechanical and thermal behavior of acrylate rubber/Fluorocarbon Elastomer/polyacrylate blends
Journal of Materials Science, 2002Co-Authors: M. Abdul Kader, A. K. Bhowmick, T. Inoue, T. ChibaAbstract:Novel thermoplastic Elastomers derived from binary and ternary blends of polyfunctional acrylates, acrylic rubber (ACM) and Fluorocarbon rubber (FKM) were analyzed by using Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA) and mechanical tests. TEM revealed the presence of a single-phase structure for both acrylate rubber/Fluorocarbon Elastomer (ACM/FKM) and ACM/polyacrylate binary blends. Increase of FKM concentration in the ACM/FKM/polyacrylate ternary blend resulted in phase separation of FKM from the ternary blend. The FKM formed a dispersed phase with polynodal particle distribution and irregular shape ranging from ellipsoidal to highly elongated form with inclusion of ACM. The FKM/polyacrylate binary blend showed complete phase separation. Ageing of the blend increased the domain size of the dispersed phase. Differential scanning calorimetric (DSC) and DMTA studies showed no major changes in the T _gs of individual polymers in the blend, although the peak tan δ values were affected on changing the composition of the blends. Vulcanization of the thermoplastic Elastomer (TPE) changed the phase morphology with increase in particle size. There is a distinct difference in morphology of statically and dynamically vulcanized blends.
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morphology mechanical and thermal behavior of acrylate rubber Fluorocarbon Elastomer polyacrylate blends
Journal of Materials Science, 2002Co-Authors: Abdul M Kader, A. K. Bhowmick, T. Inoue, T. ChibaAbstract:Novel thermoplastic Elastomers derived from binary and ternary blends of polyfunctional acrylates, acrylic rubber (ACM) and Fluorocarbon rubber (FKM) were analyzed by using Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA) and mechanical tests. TEM revealed the presence of a single-phase structure for both acrylate rubber/Fluorocarbon Elastomer (ACM/FKM) and ACM/polyacrylate binary blends. Increase of FKM concentration in the ACM/FKM/polyacrylate ternary blend resulted in phase separation of FKM from the ternary blend. The FKM formed a dispersed phase with polynodal particle distribution and irregular shape ranging from ellipsoidal to highly elongated form with inclusion of ACM. The FKM/polyacrylate binary blend showed complete phase separation. Ageing of the blend increased the domain size of the dispersed phase. Differential scanning calorimetric (DSC) and DMTA studies showed no major changes in the Tgs of individual polymers in the blend, although the peak tan δ values were affected on changing the composition of the blends. Vulcanization of the thermoplastic Elastomer (TPE) changed the phase morphology with increase in particle size. There is a distinct difference in morphology of statically and dynamically vulcanized blends.
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novel thermoplastic Elastomers from Fluorocarbon Elastomer acrylate rubber and acrylate plastics
Rubber Chemistry and Technology, 2001Co-Authors: Abdul M Kader, A. K. BhowmickAbstract:Novel thermoplastic Elastomers developed from binary and ternary blends of acrylate rubber (ACM), Fluorocarbon rubber (FKM) and multifunctional acrylates were studied using infrared (IR) spectroscopy, dynamic mechanical thermal analysis (DMTA), transmission electron microscopy (TEM), and mechanical testing. The IR study showed the presence of interaction between the constituents of binary and ternary blends with broadening, merging and shifting of characteristic bands corresponding to carbonyl group of ACM and acrylate at 1730 cm -1 . The decrease in absorbance of the double bond peak of the acrylate monomer at 1630 cm -1 was also observed due to the polymerization of acrylate monomers. Among various multifunctional acrylates used in this study, trimethylol propane triacrylate (TMPTA) showed optimum improvement in the mechanical properties of ACM/FKM blends before and after thermal aging. The best mechanical properties were obtained with 50/50/30 (w/w) ACM/FKM/TMPTA. The swelling study of these blends in various solvents with solubility parameters ranging from 8 to 25 (cal/cm 3 recorded improvement in swelling resistance. The dynamic mechanical thermal analysis indicated the presence of a single glass-transition temperature (T g ) with respect to ACM/FKM blends with a minor transition for the acrylate phase. The storage modulus (E') of the ternary blends was higher than that of the ACM/FKM binary blend at all measured temperatures.
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influence of electron beam irradiation on the mechanical properties and crosslinking of Fluorocarbon Elastomer
Radiation Physics and Chemistry, 1999Co-Authors: Indranil Banik, A. K. BhowmickAbstract:Abstract The influence of electron beam irradiation on the mechanical and dynamic mechanical properties, gel fraction and crosslink density of terpolymeric Fluorocarbon rubber has been investigated in this paper. An attempt has been made to correlate the structure of the irradiated rubber with the properties. With increase in radiation dose, an increase in degree of crosslinking results which leads to increase in modulus and Tg with a corresponding decrease in elongation at break, set and tan δ . The effect of multifunctional monomer is realized only at relatively higher level of trimethylolpropane triacrylate (TMPTA), where improvement in strength and failure properties is observed. The dynamic storage modulus at 50°C is higher and loss tangent becomes lower. Among the various polyfunctional monomers tripropyleneglycol diacrylate (TPGDA), trimethylolpropane triacrylate (TMPTA) and tetramethylolmethane tetracrylate (TMMT), the mechanical properties and the degree of crosslinking are lowest for systems based on TPGDA. MgO used in the formulation leads to the improvement in mechanical properties. Increase in the crosslink density is in line with reduced loss tangent and increased storage modulus for the MgO filled rubber vulcanizate.
R K Mondal - One of the best experts on this subject based on the ideXlab platform.
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network density tailored standalone flexible Fluorocarbon Elastomer nanocarbon black chemiresistors for 2 propanone field detection
Sensors and Actuators B-chemical, 2018Co-Authors: R K Mondal, Jitendra Kumar, K A Dubey, Y K Bhardwaj, Jose Savio MeloAbstract:Abstract 2-propanone is a commonly-used chemical and is a biomarker of diabetic ketoacidosis. Herein, the development of a novel stand-alone chemiresistive sensor with high sensitivity and selectivity for 2-propanone is reported. Fluorocarbon Elastomer (FCE)/nanocarbon black (NCB) conducting composites based chemiresistors with different crosslinking densities were synthesized via melt compounding followed by radiation crosslinking. Conducting composites in different parts of the percolation profile were chosen to establish the dependence of 2-propanone sensing response on the conducting network and the radiation cross-linked network. The chemiresistor showed a highly selective response for 2-propanone whereas a considerably lower response was noted for benzene, toluene, xylene, ethanol, methanol and water. The sensing response had a strong correlation with the FCE-analyte interaction parameter (χ12).
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Network density tailored standalone-flexible Fluorocarbon Elastomer/nanocarbon black chemiresistors for 2-propanone field detection
Sensors and Actuators B-chemical, 2018Co-Authors: R K Mondal, Jitendra Kumar, K A Dubey, Y K Bhardwaj, Jose Savio Melo, Lalit VarshneyAbstract:Abstract 2-propanone is a commonly-used chemical and is a biomarker of diabetic ketoacidosis. Herein, the development of a novel stand-alone chemiresistive sensor with high sensitivity and selectivity for 2-propanone is reported. Fluorocarbon Elastomer (FCE)/nanocarbon black (NCB) conducting composites based chemiresistors with different crosslinking densities were synthesized via melt compounding followed by radiation crosslinking. Conducting composites in different parts of the percolation profile were chosen to establish the dependence of 2-propanone sensing response on the conducting network and the radiation cross-linked network. The chemiresistor showed a highly selective response for 2-propanone whereas a considerably lower response was noted for benzene, toluene, xylene, ethanol, methanol and water. The sensing response had a strong correlation with the FCE-analyte interaction parameter (χ12).
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Development of a novel strain sensor based on Fluorocarbon–Elastomeric nanocomposites: Effect of network density on the electromechanical properties
Sensors and Actuators A-physical, 2014Co-Authors: K A Dubey, R K Mondal, Y K Bhardwaj, Vinita Grover, Avesh K. TyagiAbstract:Abstract A Fluorocarbon Elastomer (FCE)/nanocarbon black (NCB) nanocomposites based strain sensor was developed and the effect of network density on the AC and DC conductivity as well as on the electromechanical performance of the sensor was investigated. Nanocomposite matrices with different network densities were achieved by irradiating with high energy radiation from Co-60 gamma source for different doses. The nanocomposite having 0.1 weight fraction of NCB showed frequency-dependent increase in the AC conductivity (σAC) over the entire frequency range (100 Hz to 1 MHz); whereas nanocomposite having 0.2 and 0.3 weight fractions showed no significant frequency dependence. Interestingly at 0.35 weight fraction, conductor to insulator transition took place at 0.01 MHz, and a conductivity plateau was observed in 100 Hz to 0.01 MHz range. Network density was found to have a profound effect on the sensing range as well as on the gauge factor. Cyclic strain sensing response was also found to be affected by network density and the best results were observed for a network density of 73.2 μmol/g. At higher network density (290 μmol/g), two peaks were observed for each strain cycle and the sensing response was not stable. For 5 and 10% cyclic strains, gauge factor was around 14 and no change in gauge factor was observed within 2–5 mm/min strain rates.
E Shivakumar - One of the best experts on this subject based on the ideXlab platform.
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In-situ Elastomer composite based on Fluorocarbon Elastomer/liquid crystalline polymer blend
Composite Interfaces, 2012Co-Authors: E Shivakumar, K N Pandey, S Alam, G N MathurAbstract:Blends of Fluorocarbon Elastomer (FKM) and liquid crystalline polymer (LCP) have been prepared by melt mixing technique. Processing studies indicated the decrease in the viscosity and the state of cure with the addition of 10 wt% LCP, and then increased at a higher rate with the addition of more LCP to the blend. The tensile strength values decreased at lower level of LCP. However, the modulus and tear strength values increased with higher increment of LCP content. From the X-ray diffraction measurements it has been observed that the crystalline structure of the FKM is greatly affected by the addition of LCP. The degradation temperatures from thermogravimetric analysis (TGA) suggested improved thermal stability of the Fluorocarbon-LCP blends. From the dynamic mechanical analysis (DMA), it has been found that the glass transition temperature (T g) of the blends increased with increase in LCP content. For the compositions of 10 wt% and 20 wt% LCP blends, enhancement in storage modulus is found above the gla...
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influence of interactions on the mechanical morphological and thermal properties of in situ ternary composites based on Fluorocarbon Elastomer acrylic Elastomer and liquid crystalline polymer blends
Polymer International, 2005Co-Authors: E Shivakumar, K N Pandey, S AlamAbstract:The mechanical, morphological and thermal properties of the binary and ternary blends of a Fluorocarbon Elastomer (FKM), an acrylic Elastomer (ACM) and a liquid crystalline polymer (LCP) were investigated. The ternary blends were prepared by varying the amount of the LCP but fixing the ratio of the FKM and ACM. Addition of a third component, a polyacrylic rubber which interacted with the LCP, facilitated the structural development of the LCP phase by acting at the interface. The mechanical properties of the ternary blends were substantially improved because of both the fibril generation and adhesion of rubber particles on the LCP fibrils, which were attributed to the ACM interaction. Morphological investigations suggest that the fine fibrillation of the LCP domains is more apparent in the ternary blends than in the binary blends of FKM and LCP prepared under the same processing conditions. Thermogravimetric analysis (TGA) revealed an improved thermal stability of the FKM in the presence of the LCP for the binary blends, but a lower thermal stability for the ternary blends. Copyright © 2005 Society of Chemical Industry
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viscoelastic properties of ternary in situ Elastomer composites based on Fluorocarbon acrylic Elastomers and thermotropic liquid crystalline polymer blends
Polymer, 2005Co-Authors: E Shivakumar, Ester Segal, M NarkisAbstract:Abstract Dynamic mechanical analysis was performed to characterize the viscoelastic properties of binary and ternary blends of Fluorocarbon Elastomer (FKM), acrylic Elastomer (ACM) and liquid crystalline polymer (LCP). The results showed that the storage and loss modulus of all the blends increased significantly with the weight percentage of the LCP. The glass transition temperature evaluated at the loss modulus peak, were in the range of −10–+5 °C for all the blends. The time temperature superposition principle was applied for the FKM/ACM and 20% LCP filled FKM/ACM blend in order to evaluate the changes in the viscoelastic properties of FKM/ACM blend by the addition of LCP. The Arrhenius and William–Landel–Ferry (WLF) equations were used to quantify the viscoelastic behaviour at the glass transition region. Both the blends exhibited a single relaxation, which is glass transition, observed as a peek in the loss modulus at 1 Hz. The glassy moduli of these two systems were found to be comparable, but the rubbery moduli of the LCP filled FKM/ACM was much higher than the LCP unfilled system. However, the viscoelastic behaviour of these two systems and their sensitivity to time temperature may be considered to be quite similar.
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in situ Elastomer composite based on Fluorocarbon Elastomer liquid crystalline polymer blend
Composite Interfaces, 2005Co-Authors: E Shivakumar, K N Pandey, S Alam, G N MathurAbstract:Blends of Fluorocarbon Elastomer (FKM) and liquid crystalline polymer (LCP) have been prepared by melt mixing technique. Processing studies indicated the decrease in the viscosity and the state of cure with the addition of 10 wt% LCP, and then increased at a higher rate with the addition of more LCP to the blend. The tensile strength values decreased at lower level of LCP. However, the modulus and tear strength values increased with higher increment of LCP content. From the X-ray diffraction measurements it has been observed that the crystalline structure of the FKM is greatly affected by the addition of LCP. The degradation temperatures from thermogravimetric analysis (TGA) suggested improved thermal stability of the Fluorocarbon-LCP blends. From the dynamic mechanical analysis (DMA), it has been found that the glass transition temperature (T g) of the blends increased with increase in LCP content. For the compositions of 10 wt% and 20 wt% LCP blends, enhancement in storage modulus is found above the gla...
S Alam - One of the best experts on this subject based on the ideXlab platform.
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In-situ Elastomer composite based on Fluorocarbon Elastomer/liquid crystalline polymer blend
Composite Interfaces, 2012Co-Authors: E Shivakumar, K N Pandey, S Alam, G N MathurAbstract:Blends of Fluorocarbon Elastomer (FKM) and liquid crystalline polymer (LCP) have been prepared by melt mixing technique. Processing studies indicated the decrease in the viscosity and the state of cure with the addition of 10 wt% LCP, and then increased at a higher rate with the addition of more LCP to the blend. The tensile strength values decreased at lower level of LCP. However, the modulus and tear strength values increased with higher increment of LCP content. From the X-ray diffraction measurements it has been observed that the crystalline structure of the FKM is greatly affected by the addition of LCP. The degradation temperatures from thermogravimetric analysis (TGA) suggested improved thermal stability of the Fluorocarbon-LCP blends. From the dynamic mechanical analysis (DMA), it has been found that the glass transition temperature (T g) of the blends increased with increase in LCP content. For the compositions of 10 wt% and 20 wt% LCP blends, enhancement in storage modulus is found above the gla...
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influence of interactions on the mechanical morphological and thermal properties of in situ ternary composites based on Fluorocarbon Elastomer acrylic Elastomer and liquid crystalline polymer blends
Polymer International, 2005Co-Authors: E Shivakumar, K N Pandey, S AlamAbstract:The mechanical, morphological and thermal properties of the binary and ternary blends of a Fluorocarbon Elastomer (FKM), an acrylic Elastomer (ACM) and a liquid crystalline polymer (LCP) were investigated. The ternary blends were prepared by varying the amount of the LCP but fixing the ratio of the FKM and ACM. Addition of a third component, a polyacrylic rubber which interacted with the LCP, facilitated the structural development of the LCP phase by acting at the interface. The mechanical properties of the ternary blends were substantially improved because of both the fibril generation and adhesion of rubber particles on the LCP fibrils, which were attributed to the ACM interaction. Morphological investigations suggest that the fine fibrillation of the LCP domains is more apparent in the ternary blends than in the binary blends of FKM and LCP prepared under the same processing conditions. Thermogravimetric analysis (TGA) revealed an improved thermal stability of the FKM in the presence of the LCP for the binary blends, but a lower thermal stability for the ternary blends. Copyright © 2005 Society of Chemical Industry
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in situ Elastomer composite based on Fluorocarbon Elastomer liquid crystalline polymer blend
Composite Interfaces, 2005Co-Authors: E Shivakumar, K N Pandey, S Alam, G N MathurAbstract:Blends of Fluorocarbon Elastomer (FKM) and liquid crystalline polymer (LCP) have been prepared by melt mixing technique. Processing studies indicated the decrease in the viscosity and the state of cure with the addition of 10 wt% LCP, and then increased at a higher rate with the addition of more LCP to the blend. The tensile strength values decreased at lower level of LCP. However, the modulus and tear strength values increased with higher increment of LCP content. From the X-ray diffraction measurements it has been observed that the crystalline structure of the FKM is greatly affected by the addition of LCP. The degradation temperatures from thermogravimetric analysis (TGA) suggested improved thermal stability of the Fluorocarbon-LCP blends. From the dynamic mechanical analysis (DMA), it has been found that the glass transition temperature (T g) of the blends increased with increase in LCP content. For the compositions of 10 wt% and 20 wt% LCP blends, enhancement in storage modulus is found above the gla...