The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Philippe Daniel - One of the best experts on this subject based on the ideXlab platform.
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raman investigation of thermoplastic vulcanizates based on hydrogenated natural Rubber polypropylene blends
Polymer Testing, 2017Co-Authors: Korn Taksapattanakul, Tulyapong Tulyapitak, Pranee Phinyocheep, Polphat Ruamcharoen, Jareerat Ruamcharoen, Fabienne Lagarde, Mathieu Edely, Philippe DanielAbstract:Abstract Raman spectroscopy including mapping technique appears as a powerful technique for the characterization of polymer blends like thermoplastic elastomers (TPEs) and thermoplastic vulcanizates (TPVs). The Raman spectra of polymers blends such as natural Rubber/polypropylene (NR/PP) and 65% hydrogenated natural Rubber/polypropylene (65%HNR/PP) were identified and the Phase distribution was determined. The study was driven for the same type of blends in TPEs state and TPVs state obtained after to 2 different processes, either peroxide cure or sulfur cure. The morphology of TPEs and TPVs obtained by Raman spectroscopy were compared and confirmed using scanning electronic microscopy. Raman mapping shows that the Phase morphology of NR/PP, 65%HNR/PP, were characterized as continuous Rubber Phase morphology of the thermoplastic elastomers (TPEs) and a fine dispersion of cross-linked Rubber Phase in a continuous matrix of the thermoplastic vulcanizates (TPVs). Raman spectroscopy is demonstrated to be a reference to determine the content ratio of each component in the TPVs. Moreover, Raman mapping could be used to calculate the Phase size of cross-linked Rubber Phase dispersed in the thermoplastic vulcanizates (TPVs).
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Raman investigation of thermoplastic vulcanizates based on hydrogenated natural Rubber/polypropylene blends
Polymer Testing, 2017Co-Authors: Korn Taksapattanakul, Tulyapong Tulyapitak, Pranee Phinyocheep, Polphat Ruamcharoen, Jareerat Ruamcharoen, Fabienne Lagarde, Mathieu Edely, Philippe DanielAbstract:Abstract Raman spectroscopy including mapping technique appears as a powerful technique for the characterization of polymer blends like thermoplastic elastomers (TPEs) and thermoplastic vulcanizates (TPVs). The Raman spectra of polymers blends such as natural Rubber/polypropylene (NR/PP) and 65% hydrogenated natural Rubber/polypropylene (65%HNR/PP) were identified and the Phase distribution was determined. The study was driven for the same type of blends in TPEs state and TPVs state obtained after to 2 different processes, either peroxide cure or sulfur cure. The morphology of TPEs and TPVs obtained by Raman spectroscopy were compared and confirmed using scanning electronic microscopy. Raman mapping shows that the Phase morphology of NR/PP, 65%HNR/PP, were characterized as continuous Rubber Phase morphology of the thermoplastic elastomers (TPEs) and a fine dispersion of cross-linked Rubber Phase in a continuous matrix of the thermoplastic vulcanizates (TPVs). Raman spectroscopy is demonstrated to be a reference to determine the content ratio of each component in the TPVs. Moreover, Raman mapping could be used to calculate the Phase size of cross-linked Rubber Phase dispersed in the thermoplastic vulcanizates (TPVs).
Korn Taksapattanakul - One of the best experts on this subject based on the ideXlab platform.
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raman investigation of thermoplastic vulcanizates based on hydrogenated natural Rubber polypropylene blends
Polymer Testing, 2017Co-Authors: Korn Taksapattanakul, Tulyapong Tulyapitak, Pranee Phinyocheep, Polphat Ruamcharoen, Jareerat Ruamcharoen, Fabienne Lagarde, Mathieu Edely, Philippe DanielAbstract:Abstract Raman spectroscopy including mapping technique appears as a powerful technique for the characterization of polymer blends like thermoplastic elastomers (TPEs) and thermoplastic vulcanizates (TPVs). The Raman spectra of polymers blends such as natural Rubber/polypropylene (NR/PP) and 65% hydrogenated natural Rubber/polypropylene (65%HNR/PP) were identified and the Phase distribution was determined. The study was driven for the same type of blends in TPEs state and TPVs state obtained after to 2 different processes, either peroxide cure or sulfur cure. The morphology of TPEs and TPVs obtained by Raman spectroscopy were compared and confirmed using scanning electronic microscopy. Raman mapping shows that the Phase morphology of NR/PP, 65%HNR/PP, were characterized as continuous Rubber Phase morphology of the thermoplastic elastomers (TPEs) and a fine dispersion of cross-linked Rubber Phase in a continuous matrix of the thermoplastic vulcanizates (TPVs). Raman spectroscopy is demonstrated to be a reference to determine the content ratio of each component in the TPVs. Moreover, Raman mapping could be used to calculate the Phase size of cross-linked Rubber Phase dispersed in the thermoplastic vulcanizates (TPVs).
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Raman investigation of thermoplastic vulcanizates based on hydrogenated natural Rubber/polypropylene blends
Polymer Testing, 2017Co-Authors: Korn Taksapattanakul, Tulyapong Tulyapitak, Pranee Phinyocheep, Polphat Ruamcharoen, Jareerat Ruamcharoen, Fabienne Lagarde, Mathieu Edely, Philippe DanielAbstract:Abstract Raman spectroscopy including mapping technique appears as a powerful technique for the characterization of polymer blends like thermoplastic elastomers (TPEs) and thermoplastic vulcanizates (TPVs). The Raman spectra of polymers blends such as natural Rubber/polypropylene (NR/PP) and 65% hydrogenated natural Rubber/polypropylene (65%HNR/PP) were identified and the Phase distribution was determined. The study was driven for the same type of blends in TPEs state and TPVs state obtained after to 2 different processes, either peroxide cure or sulfur cure. The morphology of TPEs and TPVs obtained by Raman spectroscopy were compared and confirmed using scanning electronic microscopy. Raman mapping shows that the Phase morphology of NR/PP, 65%HNR/PP, were characterized as continuous Rubber Phase morphology of the thermoplastic elastomers (TPEs) and a fine dispersion of cross-linked Rubber Phase in a continuous matrix of the thermoplastic vulcanizates (TPVs). Raman spectroscopy is demonstrated to be a reference to determine the content ratio of each component in the TPVs. Moreover, Raman mapping could be used to calculate the Phase size of cross-linked Rubber Phase dispersed in the thermoplastic vulcanizates (TPVs).
Qiang Zheng - One of the best experts on this subject based on the ideXlab platform.
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Scaling laws of Mullins effect in nitrile butadiene Rubber nanocomposites
Polymer, 2020Co-Authors: Fuxiang Wen, Yihu Song, Munir Hussain, Qiang ZhengAbstract:Abstract Rubber nanocomposites experiencing cyclic deformation undoubtedly exhibit Mullins effect whose underlining mechanisms are not yet clear. Herein this effect in nitrile butadiene Rubber nanocomposites is systematically investigated for revealing the influences of pre-strain interval, loading and unloading velocities, temperature, filler type and content, as well as crosslinking agent. The results show that the recovery hysteresis energy and accumulative softening energy of the nanocomposites can be superposed onto master curves as a function of microscopic strain of the Rubber Phase, revealing that both involving the viscoelastic deformation of the Rubber Phase. Especially the recovery hysteresis highly depending on temperature and loading and unloading velocities is connected to the viscoelasticity of nonideally crosslinked Rubber network in the nanocomposites. On the other hand, the accumulative softening energy loss comes from recovery retardation of Rubber chains and is somewhat sensitive to the filler, temperature and crosslinking agent. The investigation would be instructive to clarify the physical origin of Mullins effect to produce low dissipation Rubber nanocomposites.
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Rigid nanoparticles promote the softening of Rubber Phase in filled vulcanizates
Polymer, 2019Co-Authors: Yihu Song, Ruiquan Yang, Xinyan Shi, Qiang ZhengAbstract:Abstract Enhanced mechanical softening accompanying nanoparticles reinforcement of Rubber is an important source of energy dissipation and heat buildup of industrially engineered elastomers. Its mechanism previously assigned to damages in the filler network, Rubber-filler interface and Rubber Phase remains controversial in more than 70 years. Through investigating the typical Payne effect of styrene-butadiene Rubber gum and its vulcanizates as well as silica filled compounds and vulcanizates and the Mullins effect of unfilled and filled vulcanizates, we herein evidence that the filler-promoted softening of the Rubber Phase softens the filled elastomer nanocomposites. Especially we show that the Mullins effect is relevantly involved in the disentanglement/re-entanglement of dangling chains superposed on the entropically elastic network of the Rubber Phase. This paper clarifies that the mechanism of nonlinear mechanical softening for filled Rubber compounds and vulcanizates should be rooted in macromolecular chains in the entanglement network (gum and filled compounds) or long dangling chain in non-ideally crosslinked network (vulcanized gum and filled vulcanizates), rather than damages involved in the “filler network” or filler-Rubber interface. This suggests that adjusting the nonideally crosslinked network structure of viscoelastic Rubber matrix should be able to optimize the use performance of the Rubber nanocomposite products.
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Fabrication of polypropylene blends with excellent low‐temperature toughness and balanced toughness‐rigidity by a combination of EPR and SEEPS
Journal of Applied Polymer Science, 2017Co-Authors: Erwen Jia, Yonggang Shangguan, Junwen Xiong, Feng Chen, Qiang ZhengAbstract:To overcome serious rigidity depression of Rubber-toughened plastics and fabricate a rigidity-toughness balanced thermoplastic, a combination of styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer (SEEPS) and ethylene-propylene Rubber (EPR) was used to toughen polypropylene. The dynamic mechanical properties, crystallization and melting behavior, and mechanical properties of polypropylene (PP)/EPR/SEEPS blends were studied in detail. The results show that the combination of SEEPS and EPR can achieve the tremendous improvement of low-temperature toughness without significant strength and rigidity loss. Dynamic mechanical properties and Phase morphology results demonstrate that there is a good interfacial strength and increased loss of compound Rubber Phase comprised of EPR component and EP domain of SEEPS. Compared with PP/EPR binary blends, although neither glass transition temperature (Tg) of the Rubber Phase nor Tg of PP matrix in PP/EPR/SEEPS blends decreases, the brittle-tough transition temperature (Tbd) of PP/EPR/SEEPS blends decreases, indicating that the increased interfacial interaction between PP matrix and compound Rubber Phase is also an effective approach to decrease Tbd of the blends so as to improve low-temperature toughness. The balance between rigidity and toughness of PP/EPR/SEEPS blends is ascribed to the synergistic effect of EPR and SEEPS on toughening PP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45714.
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A new approach to fabricate polypropylene alloy with excellent low-temperature toughness and balanced toughness-rigidity through unmatched thermal expansion coefficients between components
Polymer, 2017Co-Authors: Yonggang Shangguan, Erwen Jia, Feng Chen, Jie Yang, Qiang ZhengAbstract:Abstract A new strategy for fabricating polypropylene alloy with good low-temperature toughness was reported. Glass transition temperature (Tg) of Rubber Phase in polypropylene/ethylene-propylene Rubber/poly(styrene-b-ethylene/propylene) diblock copolymer (PP/EPR/SEP) blend was continuously reduced through strengthening the interfacial tensile force on Rubber Phase by using the concept of mismatched thermal expansion coefficient. As a result, the brittle-tough transition (BTT) of PP alloy shifted to lower temperature and subsequently excellent impact strength at low temperature was achieved. Through qualitative analysis of impact force, it was found that the theoretical temperature at which BTT occurred was close to that obtained by experiment, indicating BTT of Rubber toughened plastic system is indeed controlled by Rubber's Tg at impact instant. Furthermore, the PP alloy with excellent low-temperature toughness shows balanced toughness-rigidity, on the contrary, the blends presents poor rigidity when SEP or EPR is used to toughen PP alone.
Alfonso Maffezzoli - One of the best experts on this subject based on the ideXlab platform.
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Glass–Rubber Phase transformation detected in polymers by means of ultrasonic waves
Journal of Alloys and Compounds, 2000Co-Authors: V.a.m. Luprano, G. Montagna, B Molinas, Alfonso MaffezzoliAbstract:Abstract Ultrasonic attenuation and velocity measurements were carried out in order to study the kinetics of water sorption process in hydrogels characterized by strong structural changes occurring in the material. Hydrogel, or gel contains water, can exist in two forms: a solid glassy Phase when it is dry, a Rubber Phase in equilibrium with water. Scanning laser acoustic microscope (SLAM) technique has been used to monitor the change in the ultrasonic attenuation, during water sorption in crosslinked poly(hydroxyethylmethacrylate) and poly-vinyl alcohol (PVA) hydrogels of different thickness at the frequencies of 10 and 30 MHz. The pulse-echo technique has been applied to the measurement of the longitudinal velocity and ultrasonic attenuation and to monitor the advancement of the swollen–unswollen fronts. During the hydrogel water sorption a peak in the ultrasonic attenuation and a decrease in the longitudinal velocity have been detected. The increment in the ultrasonic attenuation has been analysed in terms of reflections from the swollen–unswollen boundary, microvoids scattering and absorption of the ultrasonic waves due to the glass to Rubber transformation.
Yihu Song - One of the best experts on this subject based on the ideXlab platform.
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Scaling laws of Mullins effect in nitrile butadiene Rubber nanocomposites
Polymer, 2020Co-Authors: Fuxiang Wen, Yihu Song, Munir Hussain, Qiang ZhengAbstract:Abstract Rubber nanocomposites experiencing cyclic deformation undoubtedly exhibit Mullins effect whose underlining mechanisms are not yet clear. Herein this effect in nitrile butadiene Rubber nanocomposites is systematically investigated for revealing the influences of pre-strain interval, loading and unloading velocities, temperature, filler type and content, as well as crosslinking agent. The results show that the recovery hysteresis energy and accumulative softening energy of the nanocomposites can be superposed onto master curves as a function of microscopic strain of the Rubber Phase, revealing that both involving the viscoelastic deformation of the Rubber Phase. Especially the recovery hysteresis highly depending on temperature and loading and unloading velocities is connected to the viscoelasticity of nonideally crosslinked Rubber network in the nanocomposites. On the other hand, the accumulative softening energy loss comes from recovery retardation of Rubber chains and is somewhat sensitive to the filler, temperature and crosslinking agent. The investigation would be instructive to clarify the physical origin of Mullins effect to produce low dissipation Rubber nanocomposites.
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Rigid nanoparticles promote the softening of Rubber Phase in filled vulcanizates
Polymer, 2019Co-Authors: Yihu Song, Ruiquan Yang, Xinyan Shi, Qiang ZhengAbstract:Abstract Enhanced mechanical softening accompanying nanoparticles reinforcement of Rubber is an important source of energy dissipation and heat buildup of industrially engineered elastomers. Its mechanism previously assigned to damages in the filler network, Rubber-filler interface and Rubber Phase remains controversial in more than 70 years. Through investigating the typical Payne effect of styrene-butadiene Rubber gum and its vulcanizates as well as silica filled compounds and vulcanizates and the Mullins effect of unfilled and filled vulcanizates, we herein evidence that the filler-promoted softening of the Rubber Phase softens the filled elastomer nanocomposites. Especially we show that the Mullins effect is relevantly involved in the disentanglement/re-entanglement of dangling chains superposed on the entropically elastic network of the Rubber Phase. This paper clarifies that the mechanism of nonlinear mechanical softening for filled Rubber compounds and vulcanizates should be rooted in macromolecular chains in the entanglement network (gum and filled compounds) or long dangling chain in non-ideally crosslinked network (vulcanized gum and filled vulcanizates), rather than damages involved in the “filler network” or filler-Rubber interface. This suggests that adjusting the nonideally crosslinked network structure of viscoelastic Rubber matrix should be able to optimize the use performance of the Rubber nanocomposite products.
