New Materials Permeable to Water Vapor

Wool, leather or cotton like most natural products are permeable to air and water vapor. The reason for this property is a fibrous structure consisting of chains of hydrophilic constituents such as cellulose or collagene. It is difficult to imitate this natural phenomenon by synthesis. Ways to obtain water vapor permeability by microporosity or a hydrophilic structure are discussed in this book (nearly 2,500 citations). Most commercial products permeable to water vapor and substitutes for natural leather are named. Materials permeable to water vapor offer a wide range of use, the subsitution of leather was only the starting point. Other uses are in the medical sector for implants and dialysis, in industry for filtration or catalytic reactions, or for processes demanding the slow release of substances. Further applications of this interesting chemistry.will surely be developed in the future.

1 Leather and Artificial Leather.- 1 Leather.- 2 Coating of Textiles.- 3 Definitions.- 4 Water Vapor Permeability.- 5 Microporous Products: Comparison of the Structure and Properties.- 2 Ways To Create Water Vapor Permeability by Elimination of Solid or Liquid Products.- 6 Ways To Create Microporosity.- 7 Elimination of Solid Particles Especially Leaching of Salts.- 8 Coagulation of Polyurethanes.- 9 Microporosity by Evaporation of Volatile Products.- 10 Reactive Processes.- 3 Porosity by Other Means.- 11 Blowing and Foaming.- 12 Microporosity by Controlled Melting Processes.- 13 Perforation.- 14 Discontinuous Coatings e.g. by Printing.- 15 Flocking.- 16 Crystallization of Homopolymers.- 17 Precipitation of Polymers in Water-Based Dispersions.- 18 Hydrophilic Polymers.- 19 Production of Synthetic Suede.- 20 Leather Board.- 21 Nonwovens.- 4 Treatment of Man-Made Leather.- 22 Finishing and Dyeing.- 23 Modification of Physical Properties by Chemical Methods.- 24 Conversion of Water Vapor Permeable Products.- 5 Chemistry, Testing Methods, Other Industrial Applications, Ecology.- 25 The Chemistry of Polyurethanes Especially for Water Vapor Permeable Products.- 26 Testing Methods.- 27 Other Industrial Applications.- 28 Ecology.- 6 Trade Names, Marketing History, Summary of Patent Applications.- 29 Comparison of Different Articles.- 30 The Development of Water Vapor Permeable Materials: Patents and Publications.- 7 Summary of Patent Applications and Practical Examples.- 31 Summary of the Patent Applications.- 32 Some Practical Examples.