Permeability oxygen transmission rate

The effect of orientation on oxygen permeability of the medium and high barrier resins is seen to be dependent upon the morphological nature of the barrier resin prior to orientation. A plot of the oxygen transmission rates as a function of the overall draw ratio (figure 3) illustrates this clearly. While the semicrystalline polymers, VDC copolymer, and aromatic nylon MXD-6, show little change in the permeability with moderate amounts of orientation in the solid state, orientation of the amorphous polymers SELAR PA 3426 and XHTA-50A causes reduction in the permeability by 5-30% in both resins, depending upon the overall level of orientation. 

Barrier Properties Exact Plastomers create controllable gas-permeable films for modified atmospheres, as well as gas-permeable films and packaging for such items as fresh vegetables, fhiits, flowers, and a growing range of other horticultural products. Users can select carbon dioxide and oxygen transmission rates (OTR) that meet their needs, with low water vapor transmission rates (WVTR) and high levels of clarity and gloss. " ... 

Polymer Oxygen transmission rate (OTR) at 25°C and 0% RH (cmVmVday) Water vapor permeability at 38°C and 90% RH (g/mVday)... 

Diffusion coefficients and solubility coefficients are the fimdamental parameters that control mass transfer in packaging systems. In practice, however, the permeability P is the most important of the permeation properties. Characteristic values for the permeability are the transmission rates (oxygen transmission rate, OTR water vapor transmission rate, WVTR). They indicate the amount of a given substance that passes a unit surface area of film per unit time, depending on the partial pressure gradient for a given temperature, the relative humidity and the given thickness of the film. 

I. 16 g mm /(m day) compared to 12.9 g mm /(m day) for the neat polymer (Yano et al., 1997). Theoretical modeling of this data shows that the variation in H O permeability and oxygen transmission rate (OTR) values, as a function of clay type, corresponds well to the natural platelet lateral dimensions for each clay. The first successful application of polymer-clay nanocomposites (PCNC) was a rtylon-6 MMT hybrid material developed by the Toyota Corporation in 1986 (Dastjerdi and Montazer, 2010). 

Oxygen-Transmission Rate See Permeability. Oxymethylene n (1) Syn Formaldehyde. (2) (oxane) The group (-OCH2-) the chain unit of Acetal Resins. 

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... 

Figure 7 shows the oxygen barrier properties as a function of the number of clay-PAM bilayers on a PET substrate. The oxygen transmission rate (OTR) and permeability decrease by an order of magnitude between 10 and 15 bilayers. The permeability of a 20-bilayer... 

Certain copolymers of this type have been found to have excellent gas barrier properties, with the dry polymer having an oxygen permeability only about 1/lOth that of polyvinylidene chloride. Unsurprisingly, the copolymer has a high moisture absorption and a high moisture vapour transmission rate. Where the material is swollen by water, gas permeability is also higher. 

Table 10 Oxygen Permeability (Transmission Rate) for Packaging Materials...

The effect of plasticizers and temperature on the permeability of small molecules in a typical vinylidene chloride copolymer has been studied thoroughly. The oxygen permeability doubles with the addition of about 1.7 parts per hundred resin (phr) of common plasticizers, or a temperature increase of 8°C (91). The effects of temperature and plasticizer on the permeability are shown in Figure 4. The moisture (water) vapor transmission rate (MVTR or WVTR) doubles with the addition of about 3.5 phr of common plasticizers (92). The dependence of the WVTR on temperature is a litde more complicated. WVTR is commonly reported at a constant difference in relative humidity and not at a constant partial pressure difference. WVTR is a mixed term that increases with increasing temperature because both the fundamental permeability and the fundamental partial pressure at constant relative humidity increase. Carbon dioxide permeability doubles with the addition of about 1.8 phr of common plasticizers, or a temperature increase of 7°C (93). 

Permeability of Thermoplastic Containers to Packaged Reagents or Proprietary Products Oxygen Gas Transmission Rate Through Plastic Film and Sheet using a Coulometric Sensor Water Permeability of Geotextiles by Permittivity Permeability of Leather to Water Vapor... 

F1927-98el Determination of Oxygen Gas Transmission Rate, Permeability and Permeance at Controlled Relative Flumidity... 

Figure 15.12. Oxygen permeability and water vapor transmission rate (WVT) behavior of PA-6/Amorphous PA-6I/6T blends at 95% RH.

The permeability coefficient, P, combines the effects of the diffusion and solubility coefficients. The barrier characteristics of a polymer are commonly associated with its permeability coefficient values. The well-known relationship P = DS holds when D is concentration independent and S follows Henry s law. Standard methods for measuring the permeability of organic compounds are not yet available. ASTM E96 describes a method for measuring the water vapor transmission rate. ASTM D1434 describes a method for the determination of oxygen permeability. 

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