SCALING DESCRIPTION OF THE AGGREGATION KINETICS OF MACROMOLECULES IN AQUEOUS GELATIN SOLUTIONS IN THE VICINITY OF GELATION THRESHOLD

A study is made of the aggregation kinetics of macromolecules of photo emulsion gelatin with the viscosity-average molecular weight M-nu = (7 .1-11.5) x 10(4) in aqueous solutions with the concentration 0.3-1.6 g dl(-1) at 293 and 299 K. Within the approximation of the lattice mode l of fractal clusters expressions are obtained relating the kinetic co nstants gamma, rates and rate constants of aggregation of macromolecul es with the relative viscosity eta(rel) of gelatin in solution, reduce d conversion time tau = gamma t, as well as with the fractal dimension D of aggregates, concentration c, and molecular weight of macromolecu les M-nu. Based on the kinetic viscosity data on eta(rel)(t) (t is the conversion time) obtained by capillary viscometry for various molecul ar weights, intrinsic viscosities [eta], and concentration of the poly mer c, kinetic aggregation parameters are calculated for the two clust er models: D = 2 and D = 2.5.