Utilising gelatin: some applications in the coatings, adhesives and allied industries—2

Methods of forming gelatin films and sheets have been published, and of semi‐permeabie membranes. The structure of dried gelatin films has been investigated, including temperature dependance of the structure forming process, and internal stresses of gelatin film applied to solid substrates. Studies of the state of absorbed water in gelatin films have been carried out, to show that the absorbed water becomes bound. Internal stresses arising from the heating of gelatin film have been found to decrease by addition of plasticisers, such as glycerol. The mechanical properties of gelatin film prepared by the evaporation of its water/solvent solutions has been investigated, and the effects of dyes and titanium dioxide on the mechanical properties of the films has been examined. The oxide was found to have negligible effects, but the dyes produced minor changes in the modulus and tensile strength, and major changes in the contraction of the film under constant stress. The effects of water on the mechanical strength of gelatin films has also been considered and compared with its effects on collagen. The permeability of potassium chloride, tetraalkyl ammonium chloride, dodecylamine chloride and uric acid, glucose and urea.