Submitted to: American Leather Chemists Association Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2011
Publication Date: N/A
Technical Abstract: We have demonstrated the effectiveness of enzymatic and chemical modification of waste protein from leather, used alone or in combination with protein from the dairy industry, in preparation of fillers for leather treatment. As we continue our research into use of sustainable resources, we are building on these and additional techniques to make products that could enhance finished leather. Vegetable tanning, utilizing polyphenols extracted from plant materials, is used primarily for production of heavy leathers for saddles, belts and shoe soles. The polyphenolic acids in vegetable tannins have been investigated extensively for their ability to modify gelatin. They can react under oxidizing conditions with side chain amino groups of peptides leading to formation of cross-links in proteins. It has also been demonstrated that biopolymer products could be made by reaction of polyphenols with proteins and pectins as well as with starch and chitosan. We explored whether gelatin, alone or in combination with other resources, when modified using polyphenols could give products with properties that might have application in leather processing. In our initial studies, before we investigated individual polyphenolic acids, we tested various tannins, to see if indeed these vegetable tannins themselves could be used in crosslinking. It was found that gelatin could be modified, using vegetable tannins, to make products that had varying physical properties such as high melting points and viscosities; it was also found that molecular weight determinations showed an extensive alteration in gelatin profile. This presentation will discuss modification parameters, characterization of products and suggest potential uses for leather processing, such as in coatings, films, adhesives or fillers.