Water Vapour Permeable PU Elastomers

Note For comfort, moisture vapour permeabiIity shouId be 4000 g m per 24 h. 

Water molecules use chemical groups along molecular chains as stepping stones to enable them to move rapidly to the outside world 

Typical water-vapour transmission rates for the various classes of breathable fabrics used are shown in Table 13.17. 

A new type of PU elastomer has been synthesized which relies on the chemical structure of the molecule for water-vapour transmission as shown in Fig. 13.14. 

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