The Experts below are selected from a list of 243 Experts worldwide ranked by ideXlab platform
Dimitrios Samios - One of the best experts on this subject based on the ideXlab platform.
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time temperature dependence of the thermo oxidative aging of Polychloroprene Rubber the time temperature transformation ttt superposition method and the lifetime prediction
Thermochimica Acta, 2002Co-Authors: Elton Luis Gasparotto Denardin, Paulo Roberto Janissek, Dimitrios SamiosAbstract:Abstract The time–temperature dependence of the thermo-oxidative aging of Polychloroprene Rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.
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time temperature dependence of the thermo oxidative aging of Polychloroprene Rubber the time temperature transformation ttt superposition method and the lifetime prediction
Thermochimica Acta, 2002Co-Authors: Elton Luis Gasparotto Denardin, Paulo Roberto Janissek, Dimitrios SamiosAbstract:Abstract The time–temperature dependence of the thermo-oxidative aging of Polychloroprene Rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.
Elton Luis Gasparotto Denardin - One of the best experts on this subject based on the ideXlab platform.
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time temperature dependence of the thermo oxidative aging of Polychloroprene Rubber the time temperature transformation ttt superposition method and the lifetime prediction
Thermochimica Acta, 2002Co-Authors: Elton Luis Gasparotto Denardin, Paulo Roberto Janissek, Dimitrios SamiosAbstract:Abstract The time–temperature dependence of the thermo-oxidative aging of Polychloroprene Rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.
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time temperature dependence of the thermo oxidative aging of Polychloroprene Rubber the time temperature transformation ttt superposition method and the lifetime prediction
Thermochimica Acta, 2002Co-Authors: Elton Luis Gasparotto Denardin, Paulo Roberto Janissek, Dimitrios SamiosAbstract:Abstract The time–temperature dependence of the thermo-oxidative aging of Polychloroprene Rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.
Paulo Roberto Janissek - One of the best experts on this subject based on the ideXlab platform.
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time temperature dependence of the thermo oxidative aging of Polychloroprene Rubber the time temperature transformation ttt superposition method and the lifetime prediction
Thermochimica Acta, 2002Co-Authors: Elton Luis Gasparotto Denardin, Paulo Roberto Janissek, Dimitrios SamiosAbstract:Abstract The time–temperature dependence of the thermo-oxidative aging of Polychloroprene Rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.
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time temperature dependence of the thermo oxidative aging of Polychloroprene Rubber the time temperature transformation ttt superposition method and the lifetime prediction
Thermochimica Acta, 2002Co-Authors: Elton Luis Gasparotto Denardin, Paulo Roberto Janissek, Dimitrios SamiosAbstract:Abstract The time–temperature dependence of the thermo-oxidative aging of Polychloroprene Rubber (CR) was studied using the time–temperature-transformation (TTT) superposition method and the IEC-216 norm. Aging of the material was performed inside temperature-controlled oven under circulated air temperature. The samples were characterized by gravimetry (G), thermogravimetric analysis (TG) and Shore A hardness before and after aging. It was demonstrated that the basic idea of Wisanrrakkit and Gilham for the TTT treatment of DSC thermal analysis data can be applied in the studies of CR aging processes. A quantitative relation between aging temperature, aging time, Shore A hardness and mass loss variation was demonstrated, which permits the prediction of lifetime under thermo-oxidative condition of CR.
Petru Budrugeac - One of the best experts on this subject based on the ideXlab platform.
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thermal degradation of glass reinforced epoxy resin and Polychloroprene Rubber the correlation of kinetic parameters of isothermal accelerated aging with those obtained from non isothermal data
Polymer Degradation and Stability, 2001Co-Authors: Petru BudrugeacAbstract:Abstract The results of a kinetic investigation of the non-isothermal and isothermal degradation of a mechanical property for glass reinforced epoxy resin (GRER) and Polychloroprene Rubber (PCL-R) are presented. For each of the materials investigated, similar dependences of the activation energy on the degree of conversion were obtained from non-isothermal data and from the thermal accelerated aging of the mechanical property (flexural strength, for GRER; residual deformation under constant deflection, for PCL-R). The obtained results are arguments for the quasichemical approximation according to which the degradation of a mechanical property of a polymeric material is due to a chemical reaction that can be described by equations from chemical kinetics. In the particular case of GRER, in which E is constant in the range 0.05⩽ α ⩽0.40, the value of the activation energy obtained from non-isothermal data can be used for rapid prediction of the thermal lifetime.
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Thermal Degradation of Polychloroprene Rubber Under Isothermal and Non-Isothermal Conditions
Journal of Thermal Analysis and Calorimetry, 1998Co-Authors: Petru Budrugeac, E. SegalAbstract:The results of a kinetic investigation of the non-isothermal degradation and the isothermal degradation of the residual deformation under constant deflection for Polychloroprene Rubber are presented. A relationship was derived between the degree of non-isothermal conversion and the value of the investigated mechanical property.
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non isothermal kinetics of reactions whose activation energy depends on the degree of conversion
Thermochimica Acta, 1995Co-Authors: Petru Budrugeac, E. SegalAbstract:A procedure for evaluating the non-isothermal kinetic parameters of reactions for which the activation energy depends on the degree of conversion is suggested. The procedure has been applied to the dehydration of calcium oxalate monohydrate and to the thermal degradation of poly(vinyl chloride) (PVC) and Polychloroprene Rubber.
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the compensation effect in the non isothermal degradation of Polychloroprene Rubber
Thermochimica Acta, 1993Co-Authors: Petru Budrugeac, E. SegalAbstract:Abstract The results of an attempt to evaluate the non-isothermal kinetic parameters for the thermal degradation of Polychloroprene Rubber are presented. The non-isothermal kinetic parameters exhibit a compensation effect.
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the kinetics of thermal degradation of polymers exhibiting a compensation effect and a linear variation of activation energy with degree of degradation
Polymer Degradation and Stability, 1992Co-Authors: Petru BudrugeacAbstract:Abstract A simple kinetic model for the thermal degradation of solid polymeric materials which exhibit a kinetic compensation effect and a linear variation of activation energy with degree of degradation is proposed. The kinetic equation is verified for the thermal degradation of Polychloroprene Rubber, in which the change of residual deformation under constant deflection as a result of thermal degradation has been investigated.
Gert Heinrich - One of the best experts on this subject based on the ideXlab platform.
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enhanced thermal stability of Polychloroprene Rubber composites with ionic liquid modified mwcnts
Polymer Degradation and Stability, 2012Co-Authors: Kalaivani Subramaniam, Amit Das, Gert Heinrich, Liane Hausler, Christina Harnisch, Klaus Werner StockelhuberAbstract:Abstract Thermal degradation of Polychloroprene Rubber (CR) composites based on unmodified and ionic liquid modified multi-walled carbon nanotubes (MWCNTs) is studied using thermogravimetric analysis (TGA) in aerobic and anaerobic (nitrogen) conditions. The CR and its composites exhibit three stage and four stage degradation in nitrogen and air respectively. The presence of unmodified CNTs alone does not improve the thermal stability of composites to a great extent whereas a reasonable enhancement is observed in case of modified CNTs/CR composites which can be attributed to the interfacial interactions of ionic liquid/modified tubes with CR and to the fine dispersion of modified tubes in CR. The degradation products of CR and its composites were analysed using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and the mechanism of degradation is discussed. Non-isothermal degradation kinetics were studied using Kissinger and Flynn-Wall-Ozawa methods and the activation energy of thermal decomposition is found to be high for modified CNTs/CR composites. Isothermal degradation of modified CNTs/CR composites at 290 °C for 30 min in nitrogen reveals decreased weight loss (14%) as opposed to CR (31%) and unmodified CNTs/CR composites (30%). The combustion behaviour of the composites was dealt using microscale combustion calorimeter (MCC) and the flame retardancy of the composites is discussed.
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effect of ionic liquid on dielectric mechanical and dynamic mechanical properties of multi walled carbon nanotubes Polychloroprene Rubber composites
European Polymer Journal, 2011Co-Authors: Kalaivani Subramaniam, Amit Das, Gert Heinrich, Dagmar Steinhauser, Manfred KluppelAbstract:Abstract This paper focuses on the influence of ionic liquid on carbon nanotube based elastomeric composites. Multi-walled carbon nanotubes (MWCNTs) are modified using an ionic liquid at room temperature, 1-butyl 3-methyl imidazolium bis (trifluoromethylsulphonyl) imide (BMI) and modified MWCNTs exhibit physical (cation–π/π–π) interaction with BMI. The Polychloroprene Rubber (CR) composites are prepared using unmodified and BMI modified MWCNTs. The presence of BMI not only increases the alternating current (AC) electrical conductivity and polarisability of the composites but also improves the state of dispersion of the tubes as observed from dielectric spectroscopy and transmission electron microscopy respectively. In addition to the hydrodynamic reinforcement, the formation of improved filler–filler networks is reflected in the dynamic storage modulus (E′) for modified MWCNTs/CR composites in amplitude sweep measurement upon increasing the proportion of BMI. Hardness and mechanical properties are also studied for the composites as a function of BMI.
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Development of conducting Polychloroprene Rubber using imidazolium based ionic liquid modified multi-walled carbon nanotubes
Composites Science and Technology, 2011Co-Authors: Kalaivani Subramaniam, Amit Das, Gert HeinrichAbstract:A simplified and an eco-friendly approach to develop Polychloroprene Rubber composites with high electrical conductivity is reported. The usage of room temperature ionic liquid, 1-butyl 3-methyl imidazolium bis(trifluoromethylsulphonyl)imide and a low concentration (5 phr) of commercial grade multi-walled carbon nanotubes (MWCNTs) in Polychloroprene Rubber exhibited an electrical conductivity of 0.1 S/cm with a stretchability >500%. The physical (cation-pi/pi-pi) interaction between the ionic liquid and the MWCNTs is evidenced by Raman spectroscopy. Transmission electron microscopy images exhibit an improved dispersion of the BMI modified tubes in matrix at various magnification scales. The dependency of dynamic properties on the concentration of ionic liquid at constant loading of nanotubes supports the fact that ionic liquid assists in the formation of filler-filler networks. The tensile modulus of 3 phr loaded modified MWCNT/CR composite is increased by 50% with regard to that of the unmodified MWCNT/CR composite. Mooney-Rivlin plot displays the existence of Rubber-filler interactions.
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influence of layered silicate on the self crosslinking of Polychloroprene and carboxylated nitrile Rubber
Macromolecular Chemistry and Physics, 2008Co-Authors: Amit Das, Klaus Werner Stockelhuber, Gert HeinrichAbstract:The effect of organically modified clay on the properties of self-crosslinkable carboxylated acrylonitrile-butadiene Rubber (XNBR) and Polychloroprene Rubber (CR) blend is studied. Results of blends produced without crosslinking agents are compared with conventional sulphur cured compounds. Sulphur cured blends exhibit improved physical properties after the incorporation of organophilic-modified clay. In contrast, the self-crosslinked blends do not show any reinforcement after the incorporation of the organoclay. XRD spectra show an intercalation of polymer chain into the gallery gap of the clay in both cases. ATR-IR, DMA and SEM studies of these composites confirm that organoclay particles constrain the self-crosslinking mechanism. The influence of the organoclay on the crystallisation of CR is also shown.