Thermodynamics of the absorption of hydrocarbon vapors in polyethylene films

Castro, E.F.; Gonzo, Elio Emilio; Gottifredi, J.C.

doi:10.1016/s0376-7388(00)82230-9

Cited by 35 publications

(24 citation statements)

References 12 publications

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“…The Sanchez−Lacombe equation of state (SL‐EOS) was used to model the solubility of ethylene in PE alone, and the solubility of a mixture of ethylene and n ‐hexane in PE. Alizadeh used the date of Yao et al and Castro et al to estimate the interaction parameters k 13 and k 23 (1 = ethylene, 2 = hexane, 3 = PE, assuming k 12 = 0). The values as a function of temperature are shown in Figure .…”

Section: Resultsmentioning

confidence: 99%

Condensed Mode Cooling for Ethylene Polymerization: Part IV. The Effect of Temperature in the Presence of Induced Condensing Agents

Andrade

McKenna

2017

Macro Chemistry & Physics

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An experimental investigation of the impact of changes in temperature on the observed rate of polymerization of ethylene in the gas phase using a commercial Ziegler–Natta catalyst in the presence of induced condensing agents (ICAs) reveals some unexpected behavior. In the absence of ICA, the effect of temperature is as expected: raising the temperature of the gas phase from 70 to 90 °C causes the observed rate of polymerization to increase monotonically. It is demonstrated in the past that ICA can increase rate of polymerization of the ethylene in the gas phase due to a cosolubility effect. However, in the current study, it is shown that when ICA is present in the reactor, the same increase in temperature can actually lead to an observable decrease in the reaction rate under certain conditions of temperature and pressure. This is attributed to a lower impact of the ICA on the solubility of ethylene in the amorphous phase of the high‐density polyethylene in the reactor at higher temperatures. An order of magnitude analysis also reveals that the presence of ICA can have an impact on the particle temperature as well.

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Section: Resultsmentioning

confidence: 99%

Condensed Mode Cooling for Ethylene Polymerization: Part IV. The Effect of Temperature in the Presence of Induced Condensing Agents

Andrade

McKenna

2017

Macro Chemistry & Physics

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“…Kulkarni and Stern6 measured the equilibrium mass uptake of CO 2 , CH 4 , C 2 H 4 , and C 3 H 8 by semicrystalline PE rods at gas pressures up to 40 atm and found that the solubility coefficient of all penetrants remained constant and within the Henry's law limits, regardless of gas pressure. Castro et al7 measured the solubility of n ‐butane, n ‐pentane, n ‐hexane, and n ‐heptane in PE membranes at very low pressures (<1 atm) and used the Flory–Huggins theory to analyze their experimental results. Hutchinson8 showed that the solubility coefficient of various gases and vapors (e.g., ethane, methane, ethylene, propylene) in semicrystalline PE followed the Henry's law.…”

Section: Introductionmentioning

confidence: 99%

Experimental and theoretical investigation of solubility and diffusion of ethylene in semicrystalline PE at elevated pressures and temperatures

Kiparissides

Dimos

Boultouka

et al. 2002

J of Applied Polymer Sci

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ABSTRACT:The solubility and diffusivity of ethylene in semicrystalline polyethylene were experimentally measured using a magnetic suspension microbalance. The sorption measurements were carried out at temperatures up to 80°C and pressures up to 66 atm. The experimentally measured solubilities were found to decrease with increasing temperature and increased with ethylene pressure in good agreement with the predictions of the Sanchez-Lacombe latticefluid model. The diffusivity of ethylene in semicrystalline polyethylene films was estimated from the reduced sorption curves using the half-time method. The experimentally determined diffusivities were compared with theoretical values predicted by a new molecular hybrid model, which combines the characteristic features of the Pace-Datyner diffusion model with those of the Kulkarni-Stern free-volume model. The ethylene diffusion coefficient was found to increase with temperature and/or the ethylene-sorbed concentration.

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“…To estimate the absorption values, unsteadystate experiments were carried out in a Cahn-RG high vacuum electrobalance following a procedure described by Castro et al 21 The samples were subjected to vacuum (1 ϫ 10 Ϫ4 mmHg) in the thermobalance until their weight achieved a constant values. The arm region where the samples were placed was immersed into a thermostatic bath at a specified temperature and the temperature was registered.…”

Section: Solubility and Diffusion Measurementsmentioning

confidence: 99%

Transport properties and mechanical behavior of poly(methyl‐phenylsiloxane) membranes as a function of methyl to phenyl groups ratio

Erdmann

Destéfanis

Abalos

et al. 2002

J of Applied Polymer Sci

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Membranes based on dimethyl and methyl-phenylsiloxane were synthesized and then fully characterized. Transport properties and mechanical behavior were determined as a function of different methyl/phenyl group ratios and the effects of these groups on results were established. Membrane transport properties were evaluated from n-hexane absorption studies. Static tensile stress-strain deformation measurements, stress-hysteresis determination, and stress-relaxation studies were performed to assess the mechanical behavior of these membranes. The results indicate that both physical-mechanical and transport properties are strongly affected by the methyl group content. The increase of the phenyl groups in the polymer chain impairs mechanical properties as a result of which decrease in crosslinking degree and gas permeability due to the diminution in free volume and penetrant solubility.

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Thermodynamics of the absorption of hydrocarbon vapors in polyethylene films

Cited by 35 publications

References 12 publications

Condensed Mode Cooling for Ethylene Polymerization: Part IV. The Effect of Temperature in the Presence of Induced Condensing Agents

Condensed Mode Cooling for Ethylene Polymerization: Part IV. The Effect of Temperature in the Presence of Induced Condensing Agents

Experimental and theoretical investigation of solubility and diffusion of ethylene in semicrystalline PE at elevated pressures and temperatures

Transport properties and mechanical behavior of poly(methyl‐phenylsiloxane) membranes as a function of methyl to phenyl groups ratio

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