Carbon dioxide permeability temperature

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). 

Figure 1.3 Oxygen and carbon dioxide permeability vs temperature through fluorinated ethylene propylene copolymer.

Mujica-Paz, H.and Gontard, N. Oxygen and Carbon dioxide permeability of WG film Efffect of relative humidity and temperature. J. Agric. FoodChem., 45, 4101 105 (1997). 

Polyethylene naphthalate (PEN), a relatively new polyester, is part of the PET family and has a great potential as a resin for bottles. PEN resin is more opaque, shows five times lower oxygen and carbon dioxide permeability coefficients, has a higher glass transition temperature, is stronger, and is stiffer than PET. This makes it more suitable for hot fiUing and a excellent material for carbonated beverages. Bottles made of PEN provide the product with additional ultraviolet protection. PEN bottles can be returnable, refiUable, and re-... 

BiaxiaHy orieated PPS film is transpareat and nearly colorless. It has low permeability to water vapor, carbon dioxide, and oxygen. PPS film has a low coefficient of hygroscopic expansion and a low dissipation factor, making it a candidate material for information storage devices and for thin-film capacitors. Chemical and thermal stability of PPS film derives from inherent resia properties. PPS films exposed to tolueae or chloroform for 8 weeks retaia 75% of theh original streagth. The UL temperature iadex rating of PPS film is 160°C for mechanical appHcatioas and 180°C for electrical appHcations. Table 9 summarizes the properties of PPS film. 

PERMANENT GASES Table 3 lists the permeabilities of oxygen [7782-44-7] nitrogen [7727-37-9] and carbon dioxide [124-38-9] for selected barrier and nonbarrier polymers at 20°C and 75% rh. The effect of temperature and humidity are discussed later. For many polymers the permeabihties of nitrogen, oxygen, and carbon dioxide are in the ratio 1 4 14. 

The poor efficiencies of coal-fired power plants in 1896 (2.6 percent on average compared with over forty percent one hundred years later) prompted W. W. Jacques to invent the high temperature (500°C to 600°C [900°F to 1100°F]) fuel cell, and then build a lOO-cell battery to produce electricity from coal combustion. The battery operated intermittently for six months, but with diminishing performance, the carbon dioxide generated and present in the air reacted with and consumed its molten potassium hydroxide electrolyte. In 1910, E. Bauer substituted molten salts (e.g., carbonates, silicates, and borates) and used molten silver as the oxygen electrode. Numerous molten salt batteiy systems have since evolved to handle peak loads in electric power plants, and for electric vehicle propulsion. Of particular note is the sodium and nickel chloride couple in a molten chloroalumi-nate salt electrolyte for electric vehicle propulsion. One special feature is the use of a semi-permeable aluminum oxide ceramic separator to prevent lithium ions from diffusing to the sodium electrode, but still allow the opposing flow of sodium ions. 

Most acrylonitrile-butadiene styrene terpolymer (ABS) is produced as a graft of SAN onto a butadiene polymer backbone. This graft copolymer may be blended with more SAN or acrylonitrile elastomer (NBR) to improve its properties. ABS is more ductile than SAN. The Tt and the heat deflection temperature of ABS vary with the composition, and ABS may have one set of values for the PBD domains and another set for the SAN matrix. The permeabilities of ABS to oxygen, nitrogen, and carbon dioxide are much less than those of hope. 

Another phenomenon found under pressure at depth in terrestrial oceans and in permafrost is gas hydrate deposits. Hydrates of natural gases such as methane (CH4-6H20) and carbon dioxide (C02-6H20) form on Earth beneath low-permeability strata under high pressure and low temperature (Kvenvolden 1993 Sloan 1998 Blunier 2000) ... 

Figure 4.20 Permeability of carbon dioxide through an alumina membrane at two different temperatures [Hsieh et al. 1991]...

C Using solubility data of a gas in a solid, explain how you would determine the molar concentration of the gas in the solid at the solid-gas interface at a specified temperature. 14-32C Using Henry s constant data for a gas dissolved in a liquid, explain how you would determine the mole fraction of the gas dissolved in the liquid al the interface at a specified tempemture. 14-33C What is permeability How is the permeability of a gas in a solid related to the solubility of the gas in that solid 14-34 Determine the mole fraction of carbon dioxide (CO2) dissolved in water at the surface of water at 300 K. The mole fraction of CO in air is 0.005, and the local atmosphere pressure is 100 kPa. 

Most acrylic roof coatings have a service temperature of 60°C. Temperatures as low as -20°C do not alter the coating performance. These coatings provide an effective barrier to carbon dioxide and permeability to water vapour. 

Step 24. Calculate the permeability to small gas molecules at room temperature. A rough estimate for the penneability to oxygen is given by equations 15.14, 15.15 and 15.17. The permeabilities to nitrogen and carbon dioxide can be predicted (even more roughly) by using equations 15.18 and 15.19, respectively. The use of ECOhi 39197 J/mole, V(298K)=97.0... 

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