COLLAGEN PROTEINS IN ELECTROREFINING - RATE CONSTANTS FOR GLUE HYDROLYSIS AND EFFECTS OF MOLAR MASS ON GLUE ACTIVITY

Animal glue (collagen proteins) degradation was studied in water and i n a simulated copper electrolyte (150 g/L H2SO4, 46 g/L Cu2+ as CuSO4) by size-exclusion chromatography. The rate of degradation was relativ ely slow in pure aqueous solutions, and depending on the temperature a nd glue concentration, some association to larger molar mass species w as observed. For simulated electrolyte in a temperature range of 42-de grees-C to 70-degrees-C and a glue concentration range of 100 to 3000 mg/L, the degradation rate constant was described with the following r elation: k' = 1.5.10(7) exp (-9951/T), min-1 The degradation rate was zero order with respect to initial concentration of the protein and fi rst order with respect to acid concentration. The results show that gl ue degradation under normal tankhouse operation should be rapid, with degradation to number-average molar mass (M(n)) < 10,000 units occurri ng in about 40 to 80 minutes depending on the mass transfer rate (or m ixing) of the electrolyte solution. Samples of glue from three differe nt sources showed almost no difference in degradation rates. Results c alculated from the rate equation for glue degradation have been correl ated with cathode polarization data from the literature, and the resul ts suggest that critical glue M(n) below which the glue loses most of its activity is 3700.