The Experts below are selected from a list of 3261 Experts worldwide ranked by ideXlab platform

Lingpu Meng - One of the best experts on this subject based on the ideXlab platform.

  • In-situ tracking polymer crystallization during Film Blowing by synchrotron radiation X-ray scattering: The critical role of network
    Polymer, 2020
    Co-Authors: Qianlei Zhang, Haoyuan Zhao, Wei Chen, Lingpu Meng, Daoliang Wang
    Abstract:

    Abstract Recent efforts attempting to in-situ track the polymer Film formation during Film Blowing are summarized. The specially designed Film Blowing apparatus is firstly introduced, where the air ring is aligned along with the die, and it's capable of installation in the synchrotron beamline (SR-beamline). Later on, detailed structural evolution of different polymeric systems during Film Blowing, including polyethylene (PE) and poly(butylene adipate-co- butylene terephthalate) (PBAT), are obtained with the assistance of simultaneous acquired Small- and Wide Angle X-ray Scattering (SAXS/WAXS). The transient structure evolution information from oriented polymer melt to final crystalline tubular Film clarifies the contribution of the crystallite-based network to final macroscopic performances. Also, the experimental results have shown the influence of intrinsic molecular characteristics and external processing parameters on the formation of stable tubular bubble. Additionally, the post-modification of the blown Film, including stretching and surface treatment is also discussed. Current experimental efforts are expected to provide more detailed parameters for mathematical modeling of Film Blowing, which could help us modify or develop new numerical models.

  • Elucidation of the relationships of structure-process-property for different ethylene/α-olefin copolymers during Film Blowing: An in-situ synchrotron radiation X-ray scattering study
    Polymer Testing, 2020
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Zhijie Xia, Erjie Yang, Zhang Mengnan, Yusong Wang, Lingpu Meng
    Abstract:

    Abstract The copolymerization of ethylene and different α-olefins could result in polyethylene (PE) with different structural topologies, and lead to polyethylene products with different macroscopic performances. Herein, three different polyethylene samples, namely low-density polyethylene (l-PE), metallocene catalyzed ethylene-hexene copolymer (h-PE) and ethylene-octene copolymer (o-PE), were selected as representatives to construct the structure-process-property relationship during Film Blowing. The detailed crystal-based network evolution during Film Blowing was first characterized by in-situ synchrotron radiation X-ray scattering. The crystallization process of l-PE Film is determined by the coupling effects of temperature and flow, while those of h-PE and o-PE Films are dominated by the temperature. Furthermore, the hierarchical crystal structure from the molecular scale to micrometers of final Films and segmental dynamics were systematically characterized by multiple ex-situ characterization techniques, i.e. Solid-State NMR, FTIR, SEM. l-PE Film shows the crystalline morphology of the row-nucleated structure, whereas h-PE and o-PE show spherulite-like superstructure with better mechanical properties. The current study tentatively constructs the relation of primary chemical structure, microstructural evolution and macroscopic performances of different polyethylene copolymers during Film Blowing.

  • Manipulation of Chain Entanglement and Crystal Networks of Biodegradable Poly(butylene adipate-co-butylene terephthalate) During Film Blowing through the Addition of a Chain Extender: An In Situ Synchrotron Radiation X-ray Scattering Study.
    Biomacromolecules, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Lingpu Meng, Zhijie Xia, Erjie Yang, Yusong Wang, Daoliang Wang
    Abstract:

    One prerequisite for the large-scale application of biodegradable polymers is the manipulation of macroscopic performances of commercially available biopolymers during processing according to different real service requirements. Herein, the microstructural evolution of poly(butylene adipate-co-butylene terephthalate) (PBAT) modified by chain extender during Film Blowing was investigated by in situ synchrotron radiation X-ray scattering to unveil the origin of different performances. The chain dynamics difference induced by the chain extender was first characterized by the rheological measurement and 1H Multiple Quantum (MQ) NMR. It shows that the terminal relaxation is significantly slowed down, while the locally segmental dynamics is not apparently changed. With the assistance of the custom-built Film Blowing apparatus, the microstructure right above the die exit (D = 13–165 mm) was in situ, simultaneously captured by small- and wide-angle scattering (SAXS/WAXS), where four distinct regimes can be define...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    ACS Applied Polymer Materials, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (i...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (iii) nucleation and growth determined by the coupling effects of both temperature and flow (LPE with low TUR). The current results are expected to guide the processing of Film Blowing as well as provide a new viewpoint for FIC study under far-from-equilibrium conditions

Haoyuan Zhao - One of the best experts on this subject based on the ideXlab platform.

  • In-situ tracking polymer crystallization during Film Blowing by synchrotron radiation X-ray scattering: The critical role of network
    Polymer, 2020
    Co-Authors: Qianlei Zhang, Haoyuan Zhao, Wei Chen, Lingpu Meng, Daoliang Wang
    Abstract:

    Abstract Recent efforts attempting to in-situ track the polymer Film formation during Film Blowing are summarized. The specially designed Film Blowing apparatus is firstly introduced, where the air ring is aligned along with the die, and it's capable of installation in the synchrotron beamline (SR-beamline). Later on, detailed structural evolution of different polymeric systems during Film Blowing, including polyethylene (PE) and poly(butylene adipate-co- butylene terephthalate) (PBAT), are obtained with the assistance of simultaneous acquired Small- and Wide Angle X-ray Scattering (SAXS/WAXS). The transient structure evolution information from oriented polymer melt to final crystalline tubular Film clarifies the contribution of the crystallite-based network to final macroscopic performances. Also, the experimental results have shown the influence of intrinsic molecular characteristics and external processing parameters on the formation of stable tubular bubble. Additionally, the post-modification of the blown Film, including stretching and surface treatment is also discussed. Current experimental efforts are expected to provide more detailed parameters for mathematical modeling of Film Blowing, which could help us modify or develop new numerical models.

  • Elucidation of the relationships of structure-process-property for different ethylene/α-olefin copolymers during Film Blowing: An in-situ synchrotron radiation X-ray scattering study
    Polymer Testing, 2020
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Zhijie Xia, Erjie Yang, Zhang Mengnan, Yusong Wang, Lingpu Meng
    Abstract:

    Abstract The copolymerization of ethylene and different α-olefins could result in polyethylene (PE) with different structural topologies, and lead to polyethylene products with different macroscopic performances. Herein, three different polyethylene samples, namely low-density polyethylene (l-PE), metallocene catalyzed ethylene-hexene copolymer (h-PE) and ethylene-octene copolymer (o-PE), were selected as representatives to construct the structure-process-property relationship during Film Blowing. The detailed crystal-based network evolution during Film Blowing was first characterized by in-situ synchrotron radiation X-ray scattering. The crystallization process of l-PE Film is determined by the coupling effects of temperature and flow, while those of h-PE and o-PE Films are dominated by the temperature. Furthermore, the hierarchical crystal structure from the molecular scale to micrometers of final Films and segmental dynamics were systematically characterized by multiple ex-situ characterization techniques, i.e. Solid-State NMR, FTIR, SEM. l-PE Film shows the crystalline morphology of the row-nucleated structure, whereas h-PE and o-PE show spherulite-like superstructure with better mechanical properties. The current study tentatively constructs the relation of primary chemical structure, microstructural evolution and macroscopic performances of different polyethylene copolymers during Film Blowing.

  • Manipulation of Chain Entanglement and Crystal Networks of Biodegradable Poly(butylene adipate-co-butylene terephthalate) During Film Blowing through the Addition of a Chain Extender: An In Situ Synchrotron Radiation X-ray Scattering Study.
    Biomacromolecules, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Lingpu Meng, Zhijie Xia, Erjie Yang, Yusong Wang, Daoliang Wang
    Abstract:

    One prerequisite for the large-scale application of biodegradable polymers is the manipulation of macroscopic performances of commercially available biopolymers during processing according to different real service requirements. Herein, the microstructural evolution of poly(butylene adipate-co-butylene terephthalate) (PBAT) modified by chain extender during Film Blowing was investigated by in situ synchrotron radiation X-ray scattering to unveil the origin of different performances. The chain dynamics difference induced by the chain extender was first characterized by the rheological measurement and 1H Multiple Quantum (MQ) NMR. It shows that the terminal relaxation is significantly slowed down, while the locally segmental dynamics is not apparently changed. With the assistance of the custom-built Film Blowing apparatus, the microstructure right above the die exit (D = 13–165 mm) was in situ, simultaneously captured by small- and wide-angle scattering (SAXS/WAXS), where four distinct regimes can be define...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    ACS Applied Polymer Materials, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (i...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (iii) nucleation and growth determined by the coupling effects of both temperature and flow (LPE with low TUR). The current results are expected to guide the processing of Film Blowing as well as provide a new viewpoint for FIC study under far-from-equilibrium conditions

Qianlei Zhang - One of the best experts on this subject based on the ideXlab platform.

  • In-situ tracking polymer crystallization during Film Blowing by synchrotron radiation X-ray scattering: The critical role of network
    Polymer, 2020
    Co-Authors: Qianlei Zhang, Haoyuan Zhao, Wei Chen, Lingpu Meng, Daoliang Wang
    Abstract:

    Abstract Recent efforts attempting to in-situ track the polymer Film formation during Film Blowing are summarized. The specially designed Film Blowing apparatus is firstly introduced, where the air ring is aligned along with the die, and it's capable of installation in the synchrotron beamline (SR-beamline). Later on, detailed structural evolution of different polymeric systems during Film Blowing, including polyethylene (PE) and poly(butylene adipate-co- butylene terephthalate) (PBAT), are obtained with the assistance of simultaneous acquired Small- and Wide Angle X-ray Scattering (SAXS/WAXS). The transient structure evolution information from oriented polymer melt to final crystalline tubular Film clarifies the contribution of the crystallite-based network to final macroscopic performances. Also, the experimental results have shown the influence of intrinsic molecular characteristics and external processing parameters on the formation of stable tubular bubble. Additionally, the post-modification of the blown Film, including stretching and surface treatment is also discussed. Current experimental efforts are expected to provide more detailed parameters for mathematical modeling of Film Blowing, which could help us modify or develop new numerical models.

  • Elucidation of the relationships of structure-process-property for different ethylene/α-olefin copolymers during Film Blowing: An in-situ synchrotron radiation X-ray scattering study
    Polymer Testing, 2020
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Zhijie Xia, Erjie Yang, Zhang Mengnan, Yusong Wang, Lingpu Meng
    Abstract:

    Abstract The copolymerization of ethylene and different α-olefins could result in polyethylene (PE) with different structural topologies, and lead to polyethylene products with different macroscopic performances. Herein, three different polyethylene samples, namely low-density polyethylene (l-PE), metallocene catalyzed ethylene-hexene copolymer (h-PE) and ethylene-octene copolymer (o-PE), were selected as representatives to construct the structure-process-property relationship during Film Blowing. The detailed crystal-based network evolution during Film Blowing was first characterized by in-situ synchrotron radiation X-ray scattering. The crystallization process of l-PE Film is determined by the coupling effects of temperature and flow, while those of h-PE and o-PE Films are dominated by the temperature. Furthermore, the hierarchical crystal structure from the molecular scale to micrometers of final Films and segmental dynamics were systematically characterized by multiple ex-situ characterization techniques, i.e. Solid-State NMR, FTIR, SEM. l-PE Film shows the crystalline morphology of the row-nucleated structure, whereas h-PE and o-PE show spherulite-like superstructure with better mechanical properties. The current study tentatively constructs the relation of primary chemical structure, microstructural evolution and macroscopic performances of different polyethylene copolymers during Film Blowing.

  • Manipulation of Chain Entanglement and Crystal Networks of Biodegradable Poly(butylene adipate-co-butylene terephthalate) During Film Blowing through the Addition of a Chain Extender: An In Situ Synchrotron Radiation X-ray Scattering Study.
    Biomacromolecules, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Lingpu Meng, Zhijie Xia, Erjie Yang, Yusong Wang, Daoliang Wang
    Abstract:

    One prerequisite for the large-scale application of biodegradable polymers is the manipulation of macroscopic performances of commercially available biopolymers during processing according to different real service requirements. Herein, the microstructural evolution of poly(butylene adipate-co-butylene terephthalate) (PBAT) modified by chain extender during Film Blowing was investigated by in situ synchrotron radiation X-ray scattering to unveil the origin of different performances. The chain dynamics difference induced by the chain extender was first characterized by the rheological measurement and 1H Multiple Quantum (MQ) NMR. It shows that the terminal relaxation is significantly slowed down, while the locally segmental dynamics is not apparently changed. With the assistance of the custom-built Film Blowing apparatus, the microstructure right above the die exit (D = 13–165 mm) was in situ, simultaneously captured by small- and wide-angle scattering (SAXS/WAXS), where four distinct regimes can be define...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    ACS Applied Polymer Materials, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (i...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (iii) nucleation and growth determined by the coupling effects of both temperature and flow (LPE with low TUR). The current results are expected to guide the processing of Film Blowing as well as provide a new viewpoint for FIC study under far-from-equilibrium conditions

Martin Zatloukal - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of convective heat transfer in 9-layer Film Blowing process by using variational principles
    International Journal of Heat and Mass Transfer, 2015
    Co-Authors: Martin Zatloukal, Roman Kolarik
    Abstract:

    Abstract In this work, coextrusion experiments utilizing an industrial 9-layer Brampton Engineering coextrusion Film Blowing line for LDPE/LDPE/tie/PA6/EVOH/PA6/tie/LDPE/LDPE Film production has been performed in order to investigate the effect of cooling intensity on the bubble shape, temperature profile and final mechanical properties of the produced multilayer Film. Obtained experimental data followed by theoretical parametric analysis were used to evaluate three different convective heat transfer models by using simple variational principle based Film Blowing model. For the studied processing conditions and given multilayer structure of the coextruded Film, it has been demonstrated experimentally that reduction in the heat transfer coefficient leads to increase in Young’s modulus and yield strength. Secondly, it has been found that the variational principle based model can describe measured multilayer bubble shape reasonably well and finally, the Muslet & Kamal heat transfer model (Muslet and Kamal, 2004) provides more realistic behavior than Campbell heat transfer model (Campbell, 2014) or Constant heat transfer coefficient model, especially if the bubble has very high freezeline height.

  • Evaluation of variational principle based model for LDPE large scale Film Blowing process
    2013
    Co-Authors: Roman Kolarik, Martin Zatloukal
    Abstract:

    In this work, variational principle based Film Blowing model combined with Pearson and Petrie formulation, considering non-isothermal processing conditions and novel generalized Newtonian model allowing to capture steady shear and uniaxial extensional viscosities has been validated by using experimentally determined bubble shape and velocity profile for LDPE sample on large scale Film Blowing line. It has been revealed that the minute change in the flow activation energy can significantly influence the Film stretching level.

  • Investigation of heat transfer in 9-layer Film Blowing process by using variational principles
    2013
    Co-Authors: Roman Kolarik, Martin Zatloukal
    Abstract:

    In this work, coextrusion experiments utilizing an industrial 9-layer Brampton Engineering coextrusion Film Blowing line has been performed under different processing conditions (low/high air cooling intensity) in order to evaluate variational principles based modeling approach using energy equation utilizing variable heat transfer coefficient along the multi-layer bubble. It has been revealed that the variational principle based model can describe the bubble shape and temperature profile reasonably well even if the multi-layer Film has been viewed as the static elastic membrane characterized only by one material parameter - bubble compliance J, which was not allow to vary along the bubble. Moreover, it has been found that if the freezeline height becomes long, heat transfer coefficient starts to vary significantly along the bubble which has crucial impact on the temperature profile along the multi-layer bubble. The performed theoretical parametric study revealed that increase in blow-up ratio or decrease in bubble curvature and air temperature causing bubble cooling efficiency increases, which allows to cooled down the multi-layer bubble for the given freezeline height to solidification temperature by smaller amount of the air volume flow rate.

  • The effect of polyolefin extensional rheology on non-isothermal Film Blowing process stability
    International Journal of Heat and Mass Transfer, 2012
    Co-Authors: Roman Kolarik, Martin Zatloukal, Michael T. Martyn
    Abstract:

    Abstract The effect of polyolefin extensional rheology on the non-isothermal Film Blowing process stability and minimum achievable final Film thickness has been investigated experimentally as well as theoretically utilizing variational principle model for the Film Blowing operation. It has been revealed experimentally as well as theoretically that the relationship between Film Blowing stability window size (and/or minimum achievable final Film thickness) and the extensional strain hardening is non-monotonic in character for a given range of melt strengths, i.e. there is existence of the optimal values for both variables to reach maximum stability window size and/or the smallest minimum achievable final Film thickness.

  • Stability analysis of non-isothermal Film Blowing process for non-Newtonian fluids using variational principles
    Chemical Engineering Science, 2012
    Co-Authors: Roman Kolarik, Martin Zatloukal, Costas Tzoganakis
    Abstract:

    Abstract In this study, a numerical stability analysis of the Film Blowing process is performed. The numerical scheme used is based on a variational principle model of the Film Blowing operation. This model employs non-isothermal processing conditions, non-Newtonian behavior of the polymer and physically limiting criteria (maximum tensile and/or hoop stress) to investigate the complex relationship between processing conditions (internal bubble pressure, heat transfer coefficient, mass flow rate, cooling air temperature, melt/die temperature), material parameters (rupture stress, Newtonian viscosity, flow activation energy, power law index) and Film Blowing stability. It has been shown that the melt/die temperature has the highest impact on the Film Blowing stability window size as well as on the maximum and minimum achievable Film thickness. In more detail, it has been found that processing parameters together with flow activation energy have much higher effect on the Film Blowing stability and maximum achievable Film thickness than the basic rheological characteristics of the polymer melt. On the other hand, the effect of basic rheological parameters of the polymer melt become much more important than processing parameters (except of melt/die temperature) in order to reach minimum Film thickness.

Daoliang Wang - One of the best experts on this subject based on the ideXlab platform.

  • In-situ tracking polymer crystallization during Film Blowing by synchrotron radiation X-ray scattering: The critical role of network
    Polymer, 2020
    Co-Authors: Qianlei Zhang, Haoyuan Zhao, Wei Chen, Lingpu Meng, Daoliang Wang
    Abstract:

    Abstract Recent efforts attempting to in-situ track the polymer Film formation during Film Blowing are summarized. The specially designed Film Blowing apparatus is firstly introduced, where the air ring is aligned along with the die, and it's capable of installation in the synchrotron beamline (SR-beamline). Later on, detailed structural evolution of different polymeric systems during Film Blowing, including polyethylene (PE) and poly(butylene adipate-co- butylene terephthalate) (PBAT), are obtained with the assistance of simultaneous acquired Small- and Wide Angle X-ray Scattering (SAXS/WAXS). The transient structure evolution information from oriented polymer melt to final crystalline tubular Film clarifies the contribution of the crystallite-based network to final macroscopic performances. Also, the experimental results have shown the influence of intrinsic molecular characteristics and external processing parameters on the formation of stable tubular bubble. Additionally, the post-modification of the blown Film, including stretching and surface treatment is also discussed. Current experimental efforts are expected to provide more detailed parameters for mathematical modeling of Film Blowing, which could help us modify or develop new numerical models.

  • Elucidation of the relationships of structure-process-property for different ethylene/α-olefin copolymers during Film Blowing: An in-situ synchrotron radiation X-ray scattering study
    Polymer Testing, 2020
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Zhijie Xia, Erjie Yang, Zhang Mengnan, Yusong Wang, Lingpu Meng
    Abstract:

    Abstract The copolymerization of ethylene and different α-olefins could result in polyethylene (PE) with different structural topologies, and lead to polyethylene products with different macroscopic performances. Herein, three different polyethylene samples, namely low-density polyethylene (l-PE), metallocene catalyzed ethylene-hexene copolymer (h-PE) and ethylene-octene copolymer (o-PE), were selected as representatives to construct the structure-process-property relationship during Film Blowing. The detailed crystal-based network evolution during Film Blowing was first characterized by in-situ synchrotron radiation X-ray scattering. The crystallization process of l-PE Film is determined by the coupling effects of temperature and flow, while those of h-PE and o-PE Films are dominated by the temperature. Furthermore, the hierarchical crystal structure from the molecular scale to micrometers of final Films and segmental dynamics were systematically characterized by multiple ex-situ characterization techniques, i.e. Solid-State NMR, FTIR, SEM. l-PE Film shows the crystalline morphology of the row-nucleated structure, whereas h-PE and o-PE show spherulite-like superstructure with better mechanical properties. The current study tentatively constructs the relation of primary chemical structure, microstructural evolution and macroscopic performances of different polyethylene copolymers during Film Blowing.

  • Manipulation of Chain Entanglement and Crystal Networks of Biodegradable Poly(butylene adipate-co-butylene terephthalate) During Film Blowing through the Addition of a Chain Extender: An In Situ Synchrotron Radiation X-ray Scattering Study.
    Biomacromolecules, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Lingpu Meng, Zhijie Xia, Erjie Yang, Yusong Wang, Daoliang Wang
    Abstract:

    One prerequisite for the large-scale application of biodegradable polymers is the manipulation of macroscopic performances of commercially available biopolymers during processing according to different real service requirements. Herein, the microstructural evolution of poly(butylene adipate-co-butylene terephthalate) (PBAT) modified by chain extender during Film Blowing was investigated by in situ synchrotron radiation X-ray scattering to unveil the origin of different performances. The chain dynamics difference induced by the chain extender was first characterized by the rheological measurement and 1H Multiple Quantum (MQ) NMR. It shows that the terminal relaxation is significantly slowed down, while the locally segmental dynamics is not apparently changed. With the assistance of the custom-built Film Blowing apparatus, the microstructure right above the die exit (D = 13–165 mm) was in situ, simultaneously captured by small- and wide-angle scattering (SAXS/WAXS), where four distinct regimes can be define...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    ACS Applied Polymer Materials, 2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (i...

  • Synergistic and Competitive Effects of Temperature and Flow on Crystallization of Polyethylene during Film Blowing
    2019
    Co-Authors: Haoyuan Zhao, Qianlei Zhang, Wei Chen, Daoliang Wang, Lingpu Meng
    Abstract:

    The influences of both temperature and external flow field on Film Blowing have been studied with a combination of a custom-built Film Blowing device and in situ synchrotron radiation small- and wide-angle X-ray scattering techniques. Polyethylene (PE) with different structural topologies, namely linear (MPE) and long-chain branched polyethylene (LPE), was used here with different responses to temperature and flow. The MPE Film shows a spherulite-like superstructure with low orientation independent of take-up ratio (TUR), while the LPE has a typical row-nucleated structure at high TUR. But for LPE Film obtained at low TUR, it exhibits the combination of both crystal morphologies. Further analysis of the microscopic structural evolution of PE during Film Blowing by synchrotron X-ray scattering reveals three different types of network evolution: (i) the temperature-induced crystallization (TIC) dominated process (MPE); (ii) the flow-induced crystallization (FIC) dominated process (LPE with high TUR); and (iii) nucleation and growth determined by the coupling effects of both temperature and flow (LPE with low TUR). The current results are expected to guide the processing of Film Blowing as well as provide a new viewpoint for FIC study under far-from-equilibrium conditions