The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
E Baer - One of the best experts on this subject based on the ideXlab platform.
-
structure property relationships of microporous membranes produced by Biaxial Orientation of compatibilized pp nylon 6 blends
Polymer, 2018Co-Authors: Jingxing Feng, Guojun Zhang, Kari Macinnis, Andrew Olah, E BaerAbstract:Abstract Microporous membranes were produced from Biaxial Orientation of polymer blends comprising polypropylene (PP), polyamide 6 (Nylon 6), and polypropylene grafted maleic anhydride (PPgMA). During Biaxial Orientation, the continuous PP domains cavitated while the dispersed Nylon 6 domains remained rigid and spherical. The effect of blend composition on cavitation was analyzed and a ternary diagram generated to identify the composition range for through-pore formation. The effects of draw ratio and initial film thickness on membrane properties were also studied. The membranes were found to have adjustable porosity up to 62% with nanoscale size pores. The filtration performance was evaluated on such membranes with varied thickness. The membranes showed very high filtration efficiency on separating 50 nm Latex microbeads from water suspensions.
-
formation of microporous membranes by Biaxial Orientation of compatibilized pp nylon 6 blends
Polymer, 2017Co-Authors: Jingxing Feng, Guojun Zhang, Kari Macinnis, Andrew Olah, E BaerAbstract:Abstract Polymer blends comprising polypropylene, Nylon 6, and a compatibilizer were extruded and Biaxially stretched. The as-extruded films with various compositions were characterized in terms of morphology, crystallization behavior, optical transparency, and oxygen barrier property. The blend films with all five compositions presented matrix-dispersed morphology with polypropylene as the continuous phase when the Nylon 6 composition is less than 55 w.t. %. The morphology was reversed when Nylon 6 composition increased to 65 w.t. %. As-extruded films exhibited high optical transparency and good oxygen barrier properties. The blend films were then Biaxially, sequentially drawn at 155 °C to draw ratio of 2.5 by 2.5. Stretching of one of the blend films containing 30% polypropylene, 55% Nylon 6, and 15% compatibilizer produced a microporous membrane with through-pore structure. The pore size of such membrane was around 100 nm with a porosity of 52%. Formation of through-pore structure was sensitive to both the composition and the process where blends with less Nylon 6 concentration or lower draw ratio would not yield through-pore structure. The generation of through pores were attributed to cavitation of polypropylene on the polypropylene-Nylon 6 interface.
-
effects of interphase modification and Biaxial Orientation on dielectric properties of poly ethylene terephthalate poly vinylidene fluoride co hexafluoropropylene multilayer films
ACS Applied Materials & Interfaces, 2016Co-Authors: Zheng Zhou, Donald E Schuele, Mason A Wolak, E BaerAbstract:Recently, poly(vinylidene fluoride) (PVDF)-based multilayer films have demonstrated enhanced dielectric properties, combining high energy density and high dielectric breakdown strength from the component polymers. In this work, further enhanced dielectric properties were achieved through interface/interphase modulation and Biaxial Orientation for the poly(ethylene terephthalate)/poly(methyl methacrylate)/poly(vinylidene fluoride-co-hexafluoropropylene) [PET/PMMA/P(VDF-HFP)] three-component multilayer films. Because PMMA is miscible with P(VDF-HFP) and compatible with PET, the interfacial adhesion between PET and P(VDF-HFP) layers should be improved. Biaxial stretching of the as-extruded multilayer films induced formation of highly oriented fibrillar crystals in both P(VDF-HFP) and PET, resulting in improved dielectric properties with respect to the unstretched films. First, the parallel Orientation of PVDF crystals reduced the dielectric loss from the αc relaxation in α crystals. Second, Biaxial stretchin...
-
effect of Biaxial Orientation on dielectric and breakdown properties of poly ethylene terephthalate poly vinylidene fluoride co tetrafluoroethylene multilayer films
Journal of Polymer Science Part B, 2013Co-Authors: Joel Carr, Donald E Schuele, Matthew Mackey, Lionel Flandin, E BaerAbstract:Polymer films with enhanced dielectric and breakdown properties are essential for the production of high energy density polymer film capacitors. By capitalizing on the synergistic effects of forced assembly nanolayer coextrusion and Biaxial Orientation, polymer multilayer films using poly(ethylene terephthalate) (PET) and a poly(vinylidene fluoride-co-tetrafluoroethylene) [P(VDF-TFE)] copolymer were produced. These films exhibited breakdown fields, under a divergent field using needle/plane electrodes, as high as 1000 kV mm−1. The energy densities of these same materials, under a uniform electric field measured using plane/plane electrodes, were as high as 16 J cm−3. The confined morphologies of both PET and P(VDF-TFE) were correlated to the observed breakdown properties and damage zones. On-edge P(VDF-TFE) crystals induced from solid-state Biaxial stretching enhanced the effective P(VDF-TFE) layer dielectric constant and therefore increased the dielectric contrast between the PET and P(VDF-TFE) layers. This resulted in additional charge buildup at the layer interface producing larger tree diameters and branches and ultimately increasing the breakdown and energy storage properties. In addition to energy storage and breakdown properties, the hysteresis behavior of these materials was also evaluated. By varying the morphology of the P(VDF-TFE) layer, the low-field dielectric loss (or ion migration behavior) could be manipulated, which in turn also changed the observed hysteresis behavior. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 882–896
-
relationship between Biaxial Orientation and oxygen permeability of polypropylene film
Polymer, 2008Co-Authors: Peter S Dias, A. Hiltner, Hongyu Chen, E BaerAbstract:Abstract Biaxially oriented polypropylene (BOPP) films were produced by simultaneous and sequential Biaxial stretching to various balanced and unbalanced draw ratios. The BOPP films were characterized in terms of density, crystallinity, refractive index, oxygen permeability and dynamic mechanical relaxation behavior. It was found that the density and crystallinity of BOPP films decreased as the area draw ratio increased. Sequential stretching led to a slightly lower density than simultaneous stretching to the same draw ratio. Moreover, sequential stretching produced lower Orientation in the first stretch direction and higher Orientation in the second stretch direction compared to simultaneous stretching. The study confirmed the generality of a one-to-one correlation between the oxygen permeability of BOPP films and the mobility of amorphous tie chains as measured by the intensity of the dynamic mechanical β-relaxation. Moreover, the study established the correlation for commercially important sequentially drawn BOPP films with an unbalanced draw ratio. Finally, the chain mobility in the stretch direction was found to depend on the final stress during stretching.
Yves Germain - One of the best experts on this subject based on the ideXlab platform.
-
Tensile drawing of ethylene/vinyl-alcohol copolymers: 3. Biaxial Orientation
Polymer, 1999Co-Authors: Roland Seguela, Karina Djezzar, Laurence Penel, J M Lefebvre, Yves GermainAbstract:Abstract The phenomenological and structural aspects of Biaxial drawing of a vinyl alcohol-rich ethylene/vinyl-alcohol copolymer is studied as a function of temperature. For draw temperature above the crystalline mechanical relaxation, T α , sharp necks accompanied with catastrophic fissures develop during simultaneous Biaxial drawing as well as in the first step of sequential Biaxial drawing. For draw temperature below T α , simultaneous Biaxial drawing can be successfully achieved via propagation of diffuse necking so that a minimum macroscopic draw ratio of about 3 × 3 is required to obtain a uniform plastic strain. The strong interaction anisotropy of the sheet-like structure of the monoclinic phase is responsible for the fissuring trend at T > T α . In contrast, the isotropic mesomorphic phase that is strain-induced at T T α enables simultaneous Biaxial drawing. The development of a planar texture suggests that the transformation results from transverse crystal slip. However, the random distribution of the H-bonds in the mesomorphic phase is rather consistent with an accumulation process of conformational defects that remain frozen in the crystal.
-
tensile drawing of ethylene vinyl alcohol copolymers 3 Biaxial Orientation
Polymer, 1999Co-Authors: Roland Seguela, Karina Djezzar, Laurence Penel, J M Lefebvre, Yves GermainAbstract:Abstract The phenomenological and structural aspects of Biaxial drawing of a vinyl alcohol-rich ethylene/vinyl-alcohol copolymer is studied as a function of temperature. For draw temperature above the crystalline mechanical relaxation, T α , sharp necks accompanied with catastrophic fissures develop during simultaneous Biaxial drawing as well as in the first step of sequential Biaxial drawing. For draw temperature below T α , simultaneous Biaxial drawing can be successfully achieved via propagation of diffuse necking so that a minimum macroscopic draw ratio of about 3 × 3 is required to obtain a uniform plastic strain. The strong interaction anisotropy of the sheet-like structure of the monoclinic phase is responsible for the fissuring trend at T > T α . In contrast, the isotropic mesomorphic phase that is strain-induced at T T α enables simultaneous Biaxial drawing. The development of a planar texture suggests that the transformation results from transverse crystal slip. However, the random distribution of the H-bonds in the mesomorphic phase is rather consistent with an accumulation process of conformational defects that remain frozen in the crystal.
Donald E Schuele - One of the best experts on this subject based on the ideXlab platform.
-
effects of interphase modification and Biaxial Orientation on dielectric properties of poly ethylene terephthalate poly vinylidene fluoride co hexafluoropropylene multilayer films
ACS Applied Materials & Interfaces, 2016Co-Authors: Zheng Zhou, Donald E Schuele, Mason A Wolak, E BaerAbstract:Recently, poly(vinylidene fluoride) (PVDF)-based multilayer films have demonstrated enhanced dielectric properties, combining high energy density and high dielectric breakdown strength from the component polymers. In this work, further enhanced dielectric properties were achieved through interface/interphase modulation and Biaxial Orientation for the poly(ethylene terephthalate)/poly(methyl methacrylate)/poly(vinylidene fluoride-co-hexafluoropropylene) [PET/PMMA/P(VDF-HFP)] three-component multilayer films. Because PMMA is miscible with P(VDF-HFP) and compatible with PET, the interfacial adhesion between PET and P(VDF-HFP) layers should be improved. Biaxial stretching of the as-extruded multilayer films induced formation of highly oriented fibrillar crystals in both P(VDF-HFP) and PET, resulting in improved dielectric properties with respect to the unstretched films. First, the parallel Orientation of PVDF crystals reduced the dielectric loss from the αc relaxation in α crystals. Second, Biaxial stretchin...
-
effect of Biaxial Orientation on dielectric and breakdown properties of poly ethylene terephthalate poly vinylidene fluoride co tetrafluoroethylene multilayer films
Journal of Polymer Science Part B, 2013Co-Authors: Joel Carr, Donald E Schuele, Matthew Mackey, Lionel Flandin, E BaerAbstract:Polymer films with enhanced dielectric and breakdown properties are essential for the production of high energy density polymer film capacitors. By capitalizing on the synergistic effects of forced assembly nanolayer coextrusion and Biaxial Orientation, polymer multilayer films using poly(ethylene terephthalate) (PET) and a poly(vinylidene fluoride-co-tetrafluoroethylene) [P(VDF-TFE)] copolymer were produced. These films exhibited breakdown fields, under a divergent field using needle/plane electrodes, as high as 1000 kV mm−1. The energy densities of these same materials, under a uniform electric field measured using plane/plane electrodes, were as high as 16 J cm−3. The confined morphologies of both PET and P(VDF-TFE) were correlated to the observed breakdown properties and damage zones. On-edge P(VDF-TFE) crystals induced from solid-state Biaxial stretching enhanced the effective P(VDF-TFE) layer dielectric constant and therefore increased the dielectric contrast between the PET and P(VDF-TFE) layers. This resulted in additional charge buildup at the layer interface producing larger tree diameters and branches and ultimately increasing the breakdown and energy storage properties. In addition to energy storage and breakdown properties, the hysteresis behavior of these materials was also evaluated. By varying the morphology of the P(VDF-TFE) layer, the low-field dielectric loss (or ion migration behavior) could be manipulated, which in turn also changed the observed hysteresis behavior. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 882–896
-
Effect of Biaxial Orientation on dielectric and breakdown properties of poly(ethylene terephthalate)/poly(vinylidene fluoride‐co‐tetrafluoroethylene) multilayer films
Journal of Polymer Science Part B, 2013Co-Authors: Joel Carr, Donald E Schuele, Matthew Mackey, Lionel Flandin, Eric BaerAbstract:Polymer films with enhanced dielectric and breakdown properties are essential for the production of high energy density polymer film capacitors. By capitalizing on the synergistic effects of forced assembly nanolayer coextrusion and Biaxial Orientation, polymer multilayer films using poly(ethylene terephthalate) (PET) and a poly(vinylidene fluoride-co-tetrafluoroethylene) [P(VDF-TFE)] copolymer were produced. These films exhibited breakdown fields, under a divergent field using needle/plane electrodes, as high as 1000 kV mm−1. The energy densities of these same materials, under a uniform electric field measured using plane/plane electrodes, were as high as 16 J cm−3. The confined morphologies of both PET and P(VDF-TFE) were correlated to the observed breakdown properties and damage zones. On-edge P(VDF-TFE) crystals induced from solid-state Biaxial stretching enhanced the effective P(VDF-TFE) layer dielectric constant and therefore increased the dielectric contrast between the PET and P(VDF-TFE) layers. This resulted in additional charge buildup at the layer interface producing larger tree diameters and branches and ultimately increasing the breakdown and energy storage properties. In addition to energy storage and breakdown properties, the hysteresis behavior of these materials was also evaluated. By varying the morphology of the P(VDF-TFE) layer, the low-field dielectric loss (or ion migration behavior) could be manipulated, which in turn also changed the observed hysteresis behavior. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 882–896
Zheng Zhou - One of the best experts on this subject based on the ideXlab platform.
-
effects of interphase modification and Biaxial Orientation on dielectric properties of poly ethylene terephthalate poly vinylidene fluoride co hexafluoropropylene multilayer films
ACS Applied Materials & Interfaces, 2016Co-Authors: Zheng Zhou, Donald E Schuele, Mason A Wolak, E BaerAbstract:Recently, poly(vinylidene fluoride) (PVDF)-based multilayer films have demonstrated enhanced dielectric properties, combining high energy density and high dielectric breakdown strength from the component polymers. In this work, further enhanced dielectric properties were achieved through interface/interphase modulation and Biaxial Orientation for the poly(ethylene terephthalate)/poly(methyl methacrylate)/poly(vinylidene fluoride-co-hexafluoropropylene) [PET/PMMA/P(VDF-HFP)] three-component multilayer films. Because PMMA is miscible with P(VDF-HFP) and compatible with PET, the interfacial adhesion between PET and P(VDF-HFP) layers should be improved. Biaxial stretching of the as-extruded multilayer films induced formation of highly oriented fibrillar crystals in both P(VDF-HFP) and PET, resulting in improved dielectric properties with respect to the unstretched films. First, the parallel Orientation of PVDF crystals reduced the dielectric loss from the αc relaxation in α crystals. Second, Biaxial stretchin...
Takashi Inoue - One of the best experts on this subject based on the ideXlab platform.
-
dual lamellar crystal structure in poly vinylidene fluoride acrylic rubber blends and its Biaxial Orientation behavior
Polymer, 2006Co-Authors: Yongjin Li, Yuko Oono, Kazuo Nakayama, Hiroshi Shimizu, Takashi InoueAbstract:Abstract The miscibility for melt-mixed poly(vinylidene fluoride) (PVDF)/acrylic rubber (ACM) blends and the crystal morphology of PVDF in the blends were investigated over the whole composition ranges by dynamic mechanical analysis (DMA), wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). DMA measurements revealed that PVDF is miscible with ACM in ACM-rich system, and partially miscible in PVDF-rich system. Two kinds of PVDF lamellar structures with different long periods were detected by SAXS and TEM for the partially miscible blends. In the miscible system, only one kind of crystal lamellae with enlarged long period is found. The two kinds of lamellar structures in the blend show different Orientation behavior during the uniaxial stretching to result in a Biaxial Orientation. The lamellae with short long period are oriented vertical to the stretching direction, while those with large long period were found to be oriented parallel to the stretching direction.
