Study on Catalytic Depolymerization of Polyurethane Using Zinc and Lead

In the present work, Polyurethane (PU) waste was depolymerized by neutral hydrolytic process in presence of zinc acetate and lead acetate as catalysts. Extent of depolymerization of polyurathene was studied by measuring the amine value of the product. The ideal quantity of catalysts, including zinc acetate and lead acetate, was discovered to be 1g. For the depolymerization of PU foam reaction, zinc acetate was a more potent catalyst than lead acetate. Based on the amine value and residual weight of the depolymerized product, the velocity constant was obtained and found to be in order of 10-3 min-1; and the reaction was found to be first order. The energy of activation and frequency factor determined by Arrhenius plot were 36.86 kJ mole -1 and 1.349 x 102 min-1 respectively. The enthalpy of activation at 1500C, 1800C, 2000C, and 2400C was recorded as 43.89, 44.39, 44.72 and 45.37 kJmole-1 respectively. The entropy of activation at the respective temperatures was recorded as 10.37 x 10-2, 9.79 x 10-2, 9.45 x 10-2 and 8.84 x 10-2 kJ mole-1.