Vapor permeability of polymers

Table II. Oxygen Permeability and Water Vapor Permeability of Polymers...

It should be noted that the gas and vapor permeability of polymer membranes could be affected by pretreatment, ageing, plasticizatitm, crosslinking and/or crystallinity of the polymer and, in some cases, by the experimental conditions and measurement techniques employed. For example, the type of solvent(s) used in the casting of membranes may affect their permeability. 

Permeability of Polymers to Gases and Vapors Brochure P302-335-79, The Dow Chemical Company, Midland, Mich., 1979. 

We test the permeability of polymer films or sheets to various vapors and gases by mounting the polymer between chambers that contain different concentrations of the migrant molecules. We can determine the permeability from pressure changes, volumetric changes, or by microanalytical techniques that measure the concentration of the migrant molecules in a stream of gas flowing across the low concentration side of the barrier. 

Permeability of Polymers to Gases, Vapors, and Liquids, Alexander Leborits, Modern... 

Permeabilities in Constant Volume/Variable Pressure Apparatus, J. Appl. Folym. Sci., 20, 1921 (1976) Measurement of Gas Permeability of Polymers. II. Apparatus for Deiemunelion of Mixed Gases and Vapors, J. Appl- Polym. Sci., 20, 287 (1976). 

The significance of plasma polymers in this respect is that a different principle applies in governing the magnitude of D and S, consequently the limiting case observed with conventional polymers does not apply to plasma polymers. A value of the water vapor permeability of a plasma polymer is also included in Table II. 

Methods u.sed to measure the permeability of polymers to vapors fall broadly into two categories, namely those for water vapor and those for volatile liquids. In both cases the most common measuring technique is the weight change or gravimetric method. Several test standards are based on this. Other methods include techniques similar to those used for gases. 

Mondal, S., and Hu, J. L. 2007. Water vapor permeability of cotton fabrics coated with shape memory polyurethane. Carbohydrate Polymers 67 282-287. 

Increase of internal stresses in the pol5rmer causes increased vapor permeability of the polymer and corrosion failure [173], and the formation of cracks that accelerate oxidation the abrasion resistance decreases [174], and the thermal and physical properties change. 

Shogren, R. (1997) Water vapor permeability of biodegradable polymers. Journal ( Environmental Polymer Degradation, 5,91-95. 

Tsuji, H., Okino, R., Daimon, H. and Fujie, K. (2006) Water vapor permeability of poly(lactide)s Effects of molecular characteristics and crystaUinity. Journal of Applied Polymer Science, 99,2245-2252. 

This chapter is a revised and updated version of Chapter 50, Permeability of Polymers to Gases and Vapors by S. A. Stem, B. Krishnakumar, and S. M. Nadakatii, published in the first edition of Physical Properties of Polymers Handbook , J. E. Mark, Editor, AIP Press, Woodbury, NY, 1996, pp. 687-700. 

H. Tsuji, R. Okino, H. Daimon and K. Fujie, Water vapor permeability of poly (lactide)s effects of molecular characteristics and crystallinity, J. Appl. Polym. Sci., 99 (2006) 2245-2252. 

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