Abstract

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Neutral hydrolytic depolymerization of the Polyurethane (PU) Foam waste was done using 0.5 L high pressure autoclave at temperatures of 150°,180°,200° and 240° C, the autogenious pressures of 75, 160, 220 and 480 psi and time intervals of 30, 45, 60 and 90 minutes. Extent of depolymerization of polyurathene was studied by measuring the amine value of the product. Optimum amount of catalysts such as zinc acetate and lead acetate was found to be 1g. Zinc acetate was more effective catalyst than lead acetate for the depolymerization of PU foam reaction. On the basis of 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 obtained by Arrhenius plot were 36.86 kJ mole^-1 and 1.349 x 102 min^-1 respectively. The enthalpy of activation at 150°C, 180°C, 200°C, and 240°C 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.

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