12 research outputs found
Directs Measurement of High Temperature/High Pressure Solubility of Methane and Carbon Dioxide in Polyamide (PA-11) using a High-Pressure Microbalance
The Accurate Measurement of Elevated Pressure Gas Permeation through Polymers Based on New Specimen Geometries
Transport properties of natural gas through polyethylene nanocomposites at high temperature and pressure
Permeation of water vapor through high performance laminates for VIPs and physical characterization of sorption and diffusion phenomena
Gas Permeation in Semicrystalline Polyethylene as Studied by Molecular Simulation and Elastic Model
We have employed molecular simulation to study the permeation of two different gases (CH4 and CO2) in polyethylene. The simulations have been performed at temperatures below the polymer melting point. Although under such conditions, polyethylene is in a semicrystalline state, we have used simulation boxes containing only a purely amorphous material. We showed in previous works [Memari P., Lachet V., Rousseau B. (2010) Polymer 51, 4978] that the effects of the complex morphology of semicrystalline materials on solubility can be implicitly taken into account by an ad-hoc constraint exerted on the amorphous phase. Here, it has been shown that our method can be applied not only for the calculation of equilibrium properties but also for transport properties like diffusion coefficients. In addition, the ad-hoc constraint has been theoretically related to the fraction of elastically effective chains in the material by making use of Michaels and Hausslein elastic model [Michaels A.S., Hausslein R.W. (1965) J. Polymer Sci.: Part C 10, 61]. We observe that the transport properties in amorphous regions are strongly governed by this fraction of elastically effective chains
Prediction and Correlation of High-Pressure Gas Solubility in Polymers with Simplified PC-SAFT
The Theory of Decompression Failure in Polymers During the High-Pressure Processing of Food
A Predictive Model for Vapor Solubility and Volume Dilation in Glassy Polymers
The nonequilibrium lattice fluid (NELF) model is here implemented with a simplified relation for bulk rheological behavior of glassy polymers, to obtain a predictive model for pseudoequilibrium solute content and volume dilation induced by swelling agents. The rheological model discussed in this work is ultimately used to derive a relation for the pseudoequilibrium volume of the polymeric system as a function of temperature and solute fugacity. The model makes use of two nonequilibrium parameters which, in turn, can be determined through the analysis of nonequilibrium pVT properties of the polymeric species. The predictive ability of the new model for solubility and volume swelling was tested by means of the comparison of model predictions and correlations with experimental data, available in the literature, for different polymer/penetrant pairs. The results obtained from the comparison allow one to conclude that the model is not just useful to describe the swelling effect of penetrants but also to recognize conditions at which plasticization by solute species induces a glass to rubber transition in the polymeric system