The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Kazuya Yamamura - One of the best experts on this subject based on the ideXlab platform.
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Adhesive-free adhesion between heat-assisted plasma-treated fluoropolymers (PTFE, PFA) and plasma-jet-treated polydimethylsiloxane (PDMS) and its application.
Scientific reports, 2018Co-Authors: Yuji Ohkubo, Katsuyoshi Endo, Kazuya YamamuraAbstract:Conventional low-temperature plasma treatment was reported to minimally improve the adhesion property of polytetrafluoroethylene (PTFE), whereas heat-assisted plasma (HAP) treatment significantly improved the same. An unvulcanized rubber was previously used as an adherent for PTFE. This study aimed to achieve strong adhesive-free adhesion between PTFE and vulcanized polydimethylsiloxane (PDMS) rubber. As-received vulcanized PDMS rubber did not adhere to HAP-treated PTFE, and as-received PTFE did not adhere to vulcanized rubber of plasma-jet (PJ) treated PDMS rubber; however, HAP-treated PTFE strongly adhered to vulcanized PJ-treated PDMS rubber, and both PTFE and PDMS exhibited cohesion failure in the T-Peel Test. The surface chemical compositions of the PTFE and PDMS sides were determined using X-ray photoelectron spectroscopy. The strong PTFE/PDMS adhesion was explained via hydrogen and covalent bond formation (C–O–Si and/or C(=O)–O–Si) between hydroxyl (C–OH) or carboxyl (C(=O)–OH) groups of the HAP-treated PTFE. This process was also applied to adhesive-free adhesion between a tetrafluoroethylene–perfluoroalkylvinylether copolymer (PFA) and PDMS; subsequently, a translucent PFA/PDMS assembly with strong adhesion was realized together with the PTFE/PDMS assembly. Strong adhesive-free adhesion between fluoropolymers (PTFE, PFA) and vulcanized PDMS rubber without using any adhesives and graft polymer was successfully realized upon plasma treatment of both the fluoropolymer and PDMS sides. Additionally, a PDMS sheet, which was PJ-treated on both sides, was applied to strongly adhere fluoropolymers (PTFE, PFA) to materials such as metal and glass. PJ-treated PDMS was used as an intermediate layer rather than a strong adhesive, achieving PTFE/PDMS/metal and PTFE/PDMS/glass assemblies. The PTFE/PDMS, PDMS/metal, and PDMS/glass adhesion strengths exceeded 2 N/mm.
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Drastic Improvement in Adhesion Property of Polytetrafluoroethylene (PTFE) via Heat-Assisted Plasma Treatment Using a Heater
Scientific Reports, 2017Co-Authors: Yuji Ohkubo, Katsuyoshi Endo, Kento Ishihara, Masafumi Shibahara, Asahiro Nagatani, Koji Honda, Kazuya YamamuraAbstract:The heating effect on the adhesion property of plasma-treated polytetrafluoroethylene (PTFE) was examined. For this purpose, a PTFE sheet was plasma-treated at atmospheric pressure while heating using a halogen heater. When plasma-treated at 8.3 W/cm^2 without using the heater (Low-P), the surface temperature of Low-P was about 95 °C. In contrast, when plasma-treated at 8.3 W/cm^2 while using the heater (Low-P+Heater), the surface temperature of Low-P+Heater was controlled to about 260 °C. Thermal compression of the plasma-treated PTFE with or without heating and isobutylene−isoprene rubber (IIR) was performed, and the adhesion strength of the IIR/PTFE assembly was measured via the T-Peel Test. The adhesion strengths of Low-P and Low-P+Heater were 0.12 and 2.3 N/mm, respectively. Cohesion failure of IIR occurred during the T-Peel Test because of its extremely high adhesion property. The surfaces of the plasma-treated PTFE with or without heating were investigated by the measurements of electron spin resonance, X-ray photoelectron spectroscopy, nanoindentation, scanning electron microscopy, and scanning probe microscopy. These results indicated that heating during plasma treatment promotes the etching of the weak boundary layer (WBL) of PTFE, resulting in a sharp increase in the adhesion property of PTFE.
Wolfgang Grellmann - One of the best experts on this subject based on the ideXlab platform.
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fracture mechanics on polyethylene polybutene 1 peel films
Polymer Testing, 2008Co-Authors: Michael Nase, Beate Langer, Wolfgang GrellmannAbstract:Abstract Sealed low-density polyethylene/isotactic polybutene-1 (PE-LD/iPB-1) peel films were investigated in this study, in consideration of fracture mechanics concepts. The T-Peel Test and the fixed arm peel Test were mainly used. A common analysis of peel curves contains only the determination of the peel force to evaluate the peel behavior. However, the existence of significantly different total peel energies necessitates the implementation of energy-determined fracture mechanics parameters in the evaluation of the peel behavior, e.g., the adhesive fracture energy release rate. The peel properties were characterized in dependence on the iPB-1 content as well as on the peel angle. The T-Peel Test revealed an exponential decrease of the adhesive energy release rate with increasing iPB-1 content. The fixed arm peel Test investigations revealed two ranges, the interlaminar and the translaminar crack propagation ranges, which could only be characterized using fracture mechanics parameters.
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effect of polymorphism of isotactic polybutene 1 on peel behavior of polyethylene polybutene 1 peel systems
Journal of Applied Polymer Science, 2008Co-Authors: Michael Nase, Beate Langer, Rene Androsch, Hans Joachim Baumann, Wolfgang GrellmannAbstract:The effect of polymorphism of isotactic polybutene-1 (iPB-1) on the peel behavior of the specific peel system low-density polyethylene/polybutene-1 (LDPE/iPB-1) was investigated using wide-angle X-ray scattering, calorimetry, and the T-Peel Test. Melt-crystallization of iPB-1, initially, yields tetragonal form II crystals which transform as a function of time to trigonal form I crystals. The kinetics of transformation at ambient temperature follows an exponential function, and is completed after about 50-75 h. The presence of LDPE in the peel system does not affect the transformation kinetics. The structure of the crystalline phase of iPB-1 controls the peel force which decreases by about 25% during the crystal-crystal transformation in a blend with 20 m% iPB-1. The reduction of the peel force depends linearly on the mass fraction of iPB-1 crystals in the peel system which further evidences the correlation between the crystal-crystal transformation of iPB-1 and the peel-characteristics of LDPE/iPB-1 blends. Isothermal reorganization of crystals of LDPE is excluded as reason for the change of the peel-performance of LDPE/iPB-1 blends, since it is 5 to 10 times faster than the decrease of the peel force, and crystal-crystal transformation of iPB-1, respectively.
Yuji Ohkubo - One of the best experts on this subject based on the ideXlab platform.
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Adhesive-free adhesion between heat-assisted plasma-treated fluoropolymers (PTFE, PFA) and plasma-jet-treated polydimethylsiloxane (PDMS) and its application.
Scientific reports, 2018Co-Authors: Yuji Ohkubo, Katsuyoshi Endo, Kazuya YamamuraAbstract:Conventional low-temperature plasma treatment was reported to minimally improve the adhesion property of polytetrafluoroethylene (PTFE), whereas heat-assisted plasma (HAP) treatment significantly improved the same. An unvulcanized rubber was previously used as an adherent for PTFE. This study aimed to achieve strong adhesive-free adhesion between PTFE and vulcanized polydimethylsiloxane (PDMS) rubber. As-received vulcanized PDMS rubber did not adhere to HAP-treated PTFE, and as-received PTFE did not adhere to vulcanized rubber of plasma-jet (PJ) treated PDMS rubber; however, HAP-treated PTFE strongly adhered to vulcanized PJ-treated PDMS rubber, and both PTFE and PDMS exhibited cohesion failure in the T-Peel Test. The surface chemical compositions of the PTFE and PDMS sides were determined using X-ray photoelectron spectroscopy. The strong PTFE/PDMS adhesion was explained via hydrogen and covalent bond formation (C–O–Si and/or C(=O)–O–Si) between hydroxyl (C–OH) or carboxyl (C(=O)–OH) groups of the HAP-treated PTFE. This process was also applied to adhesive-free adhesion between a tetrafluoroethylene–perfluoroalkylvinylether copolymer (PFA) and PDMS; subsequently, a translucent PFA/PDMS assembly with strong adhesion was realized together with the PTFE/PDMS assembly. Strong adhesive-free adhesion between fluoropolymers (PTFE, PFA) and vulcanized PDMS rubber without using any adhesives and graft polymer was successfully realized upon plasma treatment of both the fluoropolymer and PDMS sides. Additionally, a PDMS sheet, which was PJ-treated on both sides, was applied to strongly adhere fluoropolymers (PTFE, PFA) to materials such as metal and glass. PJ-treated PDMS was used as an intermediate layer rather than a strong adhesive, achieving PTFE/PDMS/metal and PTFE/PDMS/glass assemblies. The PTFE/PDMS, PDMS/metal, and PDMS/glass adhesion strengths exceeded 2 N/mm.
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Drastic Improvement in Adhesion Property of Polytetrafluoroethylene (PTFE) via Heat-Assisted Plasma Treatment Using a Heater
Scientific Reports, 2017Co-Authors: Yuji Ohkubo, Katsuyoshi Endo, Kento Ishihara, Masafumi Shibahara, Asahiro Nagatani, Koji Honda, Kazuya YamamuraAbstract:The heating effect on the adhesion property of plasma-treated polytetrafluoroethylene (PTFE) was examined. For this purpose, a PTFE sheet was plasma-treated at atmospheric pressure while heating using a halogen heater. When plasma-treated at 8.3 W/cm^2 without using the heater (Low-P), the surface temperature of Low-P was about 95 °C. In contrast, when plasma-treated at 8.3 W/cm^2 while using the heater (Low-P+Heater), the surface temperature of Low-P+Heater was controlled to about 260 °C. Thermal compression of the plasma-treated PTFE with or without heating and isobutylene−isoprene rubber (IIR) was performed, and the adhesion strength of the IIR/PTFE assembly was measured via the T-Peel Test. The adhesion strengths of Low-P and Low-P+Heater were 0.12 and 2.3 N/mm, respectively. Cohesion failure of IIR occurred during the T-Peel Test because of its extremely high adhesion property. The surfaces of the plasma-treated PTFE with or without heating were investigated by the measurements of electron spin resonance, X-ray photoelectron spectroscopy, nanoindentation, scanning electron microscopy, and scanning probe microscopy. These results indicated that heating during plasma treatment promotes the etching of the weak boundary layer (WBL) of PTFE, resulting in a sharp increase in the adhesion property of PTFE.
Michael Nase - One of the best experts on this subject based on the ideXlab platform.
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fracture mechanics on polyethylene polybutene 1 peel films
Polymer Testing, 2008Co-Authors: Michael Nase, Beate Langer, Wolfgang GrellmannAbstract:Abstract Sealed low-density polyethylene/isotactic polybutene-1 (PE-LD/iPB-1) peel films were investigated in this study, in consideration of fracture mechanics concepts. The T-Peel Test and the fixed arm peel Test were mainly used. A common analysis of peel curves contains only the determination of the peel force to evaluate the peel behavior. However, the existence of significantly different total peel energies necessitates the implementation of energy-determined fracture mechanics parameters in the evaluation of the peel behavior, e.g., the adhesive fracture energy release rate. The peel properties were characterized in dependence on the iPB-1 content as well as on the peel angle. The T-Peel Test revealed an exponential decrease of the adhesive energy release rate with increasing iPB-1 content. The fixed arm peel Test investigations revealed two ranges, the interlaminar and the translaminar crack propagation ranges, which could only be characterized using fracture mechanics parameters.
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effect of polymorphism of isotactic polybutene 1 on peel behavior of polyethylene polybutene 1 peel systems
Journal of Applied Polymer Science, 2008Co-Authors: Michael Nase, Beate Langer, Rene Androsch, Hans Joachim Baumann, Wolfgang GrellmannAbstract:The effect of polymorphism of isotactic polybutene-1 (iPB-1) on the peel behavior of the specific peel system low-density polyethylene/polybutene-1 (LDPE/iPB-1) was investigated using wide-angle X-ray scattering, calorimetry, and the T-Peel Test. Melt-crystallization of iPB-1, initially, yields tetragonal form II crystals which transform as a function of time to trigonal form I crystals. The kinetics of transformation at ambient temperature follows an exponential function, and is completed after about 50-75 h. The presence of LDPE in the peel system does not affect the transformation kinetics. The structure of the crystalline phase of iPB-1 controls the peel force which decreases by about 25% during the crystal-crystal transformation in a blend with 20 m% iPB-1. The reduction of the peel force depends linearly on the mass fraction of iPB-1 crystals in the peel system which further evidences the correlation between the crystal-crystal transformation of iPB-1 and the peel-characteristics of LDPE/iPB-1 blends. Isothermal reorganization of crystals of LDPE is excluded as reason for the change of the peel-performance of LDPE/iPB-1 blends, since it is 5 to 10 times faster than the decrease of the peel force, and crystal-crystal transformation of iPB-1, respectively.
Zehra Yildiz - One of the best experts on this subject based on the ideXlab platform.
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dual curable pvb based adhesive formulations for cord rubber composites the influence of reactive diluents
International Journal of Adhesion and Adhesives, 2017Co-Authors: Zehra Yildiz, Hacer Aysen OnenAbstract:Abstract In this study, the effects of reactive diluent type on the adhesion strength of cord/rubber surfaces were investigated. For this purpose, a urethane acrylate oligomer was synthesized by the reaction of 2,4-toluene diisocyanate (TDI), 2-hydroxyethyl methacrylate (HEMA) and polyvinyl butyral (PVB) in the presence of di-n-butyltin dilaurate (T12) as catalyst. The structure of the oligomer was characterized by nuclear magnetic resonance (NMR) spectroscopy. Then the oligomer was included in adhesive formulations together with trimethylolpropane trimethacrylate (TMPTMA) and tricyclodecane dimethanol diacrylate (TCDDA) as reactive diluent s and thermal and photo initiator respectively. Polyester/polyamide cord fabrics were dipped into the adhesive solution and cured by UV-light. Then coated fabrics were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Contact angle measurement was employed to investigate the wettability properties of the coated fabrics. Thermal curing between the coated fabric and rubber was performed under heat and pressure. The adhesion strength between the cord/rubber surfaces was determined by T-Peel Test. The highest adhesion strength of 100.4 N/cm with the lowest contact angle value of 70.2° were obtained in the sample containing TCDDA as reactive diluent, due to a higher functionality resulting in a greater crosslinking density.
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synthesis and application of dual curable pvb based adhesive formulations for cord rubber applications
Journal of Adhesion Science and Technology, 2017Co-Authors: Zehra Yildiz, Hacer Aysen Onen, Atilla Gungor, Youjiang Wang, Karl I JacobAbstract:AbstractIn this research, formaldehyde-free dual-curable adhesive formulations containing polyvinyl butyral (PVB) were prepared with the reaction of 2,4-toluene diisocyanate (TDI) and 2-hydroxyethyl methacrylate (HEMA) and then applied on cord fabrics upon adhere onto the rubber surfaces. The effects of PVB ratio on peel strength value between the cord and rubber were studied. The structure of the oligomer was characterized by FTIR and 1H NMR spectroscopy. Thermal properties of coated and UV-cured fabrics were investigated by TGA and DSC. Surface wettability properties of the fabrics after coating were observed with contact angle measurement. The peel strength between cord/rubber surfaces was determined by T-Peel Test after thermal curing stage under heat and pressure. Results showed that peel strength value increases with increasing PVB amount in the formulation. The highest peel strength of 94.7 N/cm was observed when 5% PVB was included in the formulation. This study leads to a new type of promising ad...
