Patent ID: 8163350

Claim:
A process for fabricating a selectively permeable finished article, comprising: (a) forming a solution of a chitosan moiety, (b) depositing a quantity of the chitosan solution sufficient to form a film on a nonporous substrate, wherein the substrate comprises a film comprising a polar polymer or a sheet comprising a polar polymer, wherein the polar polymer is an elastomer, glassy polymer, or semi-crystalline material; (c) drying the deposited chitosan solution on the substrate, thereby forming a continuous chitosan film; (d) heating the chitosan film at a temperature in the range of 100° C. to 180° C. for a time sufficient to make the film water-insoluble without adding a crosslinking agent; (e) optionally, depositing an additional layer onto the chitosan film; (f) forming a laminate having layers comprising the substrate and the chitosan film and at least one layer of fabric, wherein at least two layers of the laminate are attached to each other using an array of adhesive dots, adhesive lines, or adhesive curves; wherein the laminate has the properties of: a Moisture Vapor Transport Rate of at least 2 kg/m 2 /24 h, a transport rate of <4.0 μg/cm 2 one hour cumulative permeation for mustard, and a transport rate of <1.25 μg/cm 2 one hour cumulative permeation for Soman; and (g) fabricating a finished article incorporating the laminate, said article being chemically protective and selectively permeable to water vapor, wherein the finished article is selected from the group consisting of: items of apparel selected from the group consisting of coveralls, protective suits, coats, jackets, raingear, ski pants, gloves, socks, boots, shoe or boot covers, trousers, hoods, hats, masks, shirts, and medical garments; shelters, and protective covers.