Water vapour permeable polyurethanes

These have become commercially important as a means of obtaining a flexible membrane of controlled water-vapour permeability which finds applications as a replacement for leather, laminates for waterproof garments and various medical uses. Polyurethanes are superior to other plastics and rubbers due to their following combination of properties ... 

Jeong H.M., Ahn B. and Kim B.K. (2000), Temperature sensitive water vapour permeability and shape memory effect of polyurethane with crystalline reversible phase and hydrophilic segments. Polymer International, 49 pp. 1714-1721. 

The activated carbon granules were coated in substrates (e.g., polyurethane foam and non-woven pads) for use as an interliner in the clothing system however, the coated polyurethane foam usually has low air and water vapour permeabihty, and it is reported that needle-punched fabrics coated with activated carbon have better thermal comfort properties. The coated activated carbon material is combined with other textile materials in permeable CPC to provide two main functions ... 

PE foams exhibit a superior ability to absorb mechanical impact, reduced hygroscopicity, low permeability to water vapours, and good resistance to weathering and chemicals compared to polystyrene (PS) and polyurethane (PU) foams. They are rigid or flexible foams depending on the volume increase which may be anything from three to five to as much as 40 times the initial volume. 

Adhesive nanocomposites of polyurethane and montmorillonite modified with different organic residues have been synthesized and their permeability to oxygen and water vapour has been measured by Osman et al. The oxygen transmission rate asymptotically decayed with increasing aluminosilicate volume fraction and a 30% reduction was achieved at 3 vol.%, when the elay... 

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