Experimental estimation of gas-transport properties of linear low-density polyethylene membranes by an integral permeation method

2001 ◽  
Vol 82 (12) ◽  
pp. 3013-3021 ◽  
Author(s):  
J. P. G. Villaluenga ◽  
B. Seoane
Keyword(s):  
Transport Properties ◽  
Gas Transport ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Gas Transport Properties ◽  
Experimental Estimation

scholarly journals Hollow Fiber Porous Nanocomposite Membranes Produced via Continuous Extrusion: Morphology and Gas Transport Properties

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2311 ◽  
Author(s):  
Zahir Razzaz ◽  
Denis Rodrigue
Keyword(s):  
Transport Properties ◽  
Hollow Fiber ◽  
Cellular Structure ◽  
Gas Transport ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Nanocomposite Membranes ◽  
Gas Transport Properties ◽  
Continuous Extrusion ◽  
Porous Nanocomposite

In this work, hollow fiber porous nanocomposite membranes were successfully prepared by the incorporation of a porous nanoparticle (zeolite 5A) into a blend of linear low-density polyethylene (LLDPE)/low-density polyethylene (LDPE) combined with azodicarbonamide as a chemical blowing agent (CBA). Processing was performed via continuous extrusion using a twin-screw extruder coupled with a calendaring system. The process was firstly optimized in terms of extrusion and post-extrusion conditions, as well as formulation to obtain a good cellular structure (uniform cell size distribution and high cell density). Scanning electron microscopy (SEM) was used to determine the cellular structure as well as nanoparticle dispersion. Then, the samples were characterized in terms of mechanical and thermal stability via tensile tests and thermogravimetric analysis (TGA), as well as differential scanning calorimetry (DSC). The results showed that the zeolite nanoparticles were able to act as effective nucleating agents during the foaming process. However, the optimum nanoparticle content was strongly related to the foaming conditions. Finally, the membrane separation performances were investigated for different gases (CO2, CH4, N2, O2, and H2) showing that the incorporation of porous zeolite significantly improved the gas transport properties of semi-crystalline polyolefin membranes due to lower cell wall thickness (controlling permeability) and improved separation properties (controlling selectivity). These results show that mixed matrix membranes (MMMs) can be cost-effective, easy to process, and efficient in terms of processing rate, especially for the petroleum industry where H2/CH4 and H2/N2 separation/purification are important for hydrogen recovery.

Crystallinity effect on the gas transport in semicrystalline coextruded films based on linear low density polyethylene

2010 ◽  
Vol 48 (6) ◽  
pp. 634-642 ◽  
Author(s):  
Vicente Compañ ◽  
L. F. Del Castillo ◽  
S. I. Hernández ◽  
M. Mar López-González ◽  
Evaristo Riande
Keyword(s):  
Gas Transport ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene

Mechanical and transport properties of irradiated linear low density polyethylene (LLDPE)

2001 ◽  
Vol 72 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Carlo Naddeo ◽  
Liberata Guadagno ◽  
Simonetta De Luca ◽  
Vittoria Vittoria ◽  
Giovanni Camino
Keyword(s):  
Transport Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene

The Effect of the Type and Concentration of the Crosslinking Diene on the Gas Transport Properties of Membranes Based on Polyoctylmethylsiloxane

2020 ◽  
Vol 2 (6) ◽  
pp. 399-406
Author(s):  
E. A. Grushevenko ◽  
I. L. Borisov ◽  
D. S. Bakhtin ◽  
V. V. Volkov ◽  
A. V. Volkov
Keyword(s):  
Transport Properties ◽  
Gas Transport ◽  
Gas Transport Properties

scholarly journals Identification of the LLDPE Constitutive Material Model for Energy Absorption in Impact Applications

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1537
Author(s):  
Luděk Hynčík ◽  
Petra Kochová ◽  
Jan Špička ◽  
Tomasz Bońkowski ◽  
Robert Cimrman ◽  
...  
Keyword(s):  
Strain Rate ◽  
Material Model ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Stress Strain ◽  
Rate Dependent ◽  
Constitutive Material Model ◽  
Principal Directions ◽  
Constitutive Material

Current industrial trends bring new challenges in energy absorbing systems. Polymer materials as the traditional packaging materials seem to be promising due to their low weight, structure, and production price. Based on the review, the linear low-density polyethylene (LLDPE) material was identified as the most promising material for absorbing impact energy. The current paper addresses the identification of the material parameters and the development of a constitutive material model to be used in future designs by virtual prototyping. The paper deals with the experimental measurement of the stress-strain relations of linear low-density polyethylene under static and dynamic loading. The quasi-static measurement was realized in two perpendicular principal directions and was supplemented by a test measurement in the 45° direction, i.e., exactly between the principal directions. The quasi-static stress-strain curves were analyzed as an initial step for dynamic strain rate-dependent material behavior. The dynamic response was tested in a drop tower using a spherical impactor hitting a flat material multi-layered specimen at two different energy levels. The strain rate-dependent material model was identified by optimizing the static material response obtained in the dynamic experiments. The material model was validated by the virtual reconstruction of the experiments and by comparing the numerical results to the experimental ones.

New poly(ether imide)s with pendant di-tert-butyl groups: Synthesis, characterization and gas transport properties

2019 ◽  
Vol 217 ◽  
pp. 183-194 ◽  
Author(s):  
N. Belov ◽  
R. Chatterjee ◽  
R. Nikiforov ◽  
V. Ryzhikh ◽  
S. Bisoi ◽  
...  
Keyword(s):  
Transport Properties ◽  
Gas Transport ◽  
Tert Butyl ◽  
Gas Transport Properties

scholarly journals A Molecular Simulation Study of Silica/Polysulfone Mixed Matrix Membrane for Mixed Gas Separation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2199
Author(s):  
Khadija Asif ◽  
Serene Sow Mun Lock ◽  
Syed Ali Ammar Taqvi ◽  
Norwahyu Jusoh ◽  
Chung Loong Yiin ◽  
...  
Keyword(s):  
Transport Properties ◽  
Molecular Simulation ◽  
Gas Separation ◽  
Membrane Separation ◽  
Gas Transport ◽  
Mixed Matrix ◽  
Mixed Gas ◽  
Gas Transport Properties ◽  
Simulation Results ◽  
Mixed Gases

Polysulfone-based mixed matrix membranes (MMMs) incorporated with silica nanoparticles are a new generation material under ongoing research and development for gas separation. However, the attributes of a better-performing MMM cannot be precisely studied under experimental conditions. Thus, it requires an atomistic scale study to elucidate the separation performance of silica/polysulfone MMMs. As most of the research work and empirical models for gas transport properties have been limited to pure gas, a computational framework for molecular simulation is required to study the mixed gas transport properties in silica/polysulfone MMMs to reflect real membrane separation. In this work, Monte Carlo (MC) and molecular dynamics (MD) simulations were employed to study the solubility and diffusivity of CO2/CH4 with varying gas concentrations (i.e., 30% CO2/CH4, 50% CO2/CH4, and 70% CO2/CH4) and silica content (i.e., 15–30 wt.%). The accuracy of the simulated structures was validated with published literature, followed by the study of the gas transport properties at 308.15 K and 1 atm. Simulation results concluded an increase in the free volume with an increasing weight percentage of silica. It was also found that pure gas consistently exhibited higher gas transport properties when compared to mixed gas conditions. The results also showed a competitive gas transport performance for mixed gases, which is more apparent when CO2 increases. In this context, an increment in the permeation was observed for mixed gas with increasing gas concentrations (i.e., 70% CO2/CH4 > 50% CO2/CH4 > 30% CO2/CH4). The diffusivity, solubility, and permeability of the mixed gases were consistently increasing until 25 wt.%, followed by a decrease for 30 wt.% of silica. An empirical model based on a parallel resistance approach was developed by incorporating mathematical formulations for solubility and permeability. The model results were compared with simulation results to quantify the effect of mixed gas transport, which showed an 18% and 15% percentage error for the permeability and solubility, respectively, in comparison to the simulation data. This study provides a basis for future understanding of MMMs using molecular simulations and modeling techniques for mixed gas conditions that demonstrate real membrane separation.

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