Gel-sol transitions of chrome tanned leather waste hydrolysate

The properties of gels of collagenous hydrolysates from enzyme treatment of chrome-tanned leather waste, were monitored with the use of the DSC techni que. The temperatures at which gels melt, the energies of the gel-sol trans itions (determined by use of the DSC technique) and the gel strength (in de grees Bloom) correspond to those of gels of the qualitative class 9-10, as specified by the National Association of Clue Manufacturers. Due to the low er mean molecular weight of the hydrolysates (when compared with commercial ly available glues) and the wider molecular weight distribution, hydrolysed gels from enzyme hydrolysates (hydrolysis times less than 3 h) are used at concentrations approximately three times higher than is usual with commerc ially available glues of the above-mentioned quality. Glues of this qualitative class are often used in industry in concentration s of 50% and higher and thus the higher concentration of hydrolysates from chrome-tanned leather waste will not represent an obstacle when they are us ed in a similar way.