On the crystallinity effect on the gas sorption in semicrystalline linear low density polyethylene (LLDPE) |
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| Authors: | Vicente Compañ L F Del Castillo S I Hernández M Mar López‐González Evaristo Riande |
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| Institution: | 1. Departamento de Termodinámica Aplicada, ETSII, Universidad Politécnica de Valencia, Campus de Vera s/n. 46022‐Valencia, SpainDepartamento de Termodinámica Aplicada, ETSII, Universidad Politécnica de Valencia, Campus de Vera s/n. 46022‐Valencia, Spain;2. Departamento de Polímeros, Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70‐360, Coyoacán, México DF, 04510, Mexico;3. Instituto de Ciencia y Tecnología de Polímeros (CSIC), 28006 Madrid, Spain |
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| Abstract: | This article describes the solubility of carbon dioxide, ethylene and propane in 1‐octene based polyethylene of 0.94, 0.92, 0.904, and 0.87 densities. The isotherms obtained in the gas sorption experimental device display a sorption behavior similar to that of glassy polymers. We apply the dual model to semicrystalline polymers assuming that Henry's sites are related to the amorphous phase, which decreases when the crystallinity percentage increases, whereas the surface of the crystalline phase acts as a Langmuir site with higher gas‐polymer affinity than glassy polymers. The good concordance of the calculated kD values, using the Flory‐Huggins theory of polymer diluent mixtures, with the experimental results suggest that Henry's gas sorption fulfills this theory and, therefore, it may be a suitable way to estimate polymer‐gas enthalpic interactions. Particularly, the variation of kD with the crystallinity fraction is exponential and the proportionality of the total sorption with the amorphous content seems only apparent. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1798–1807, 2007 |
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| Keywords: | gas diffusion permeability solubility sorption |
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