Kinetics of Powder-Free Laboratory Examination Gloves at 323°C and 408°C by Thermogravimetric Analysis

Abstract

At two isotherm temperatures, 323°C and 408°C, and two thermal scans the kinetics of thermolysis of powder-free laboratory safety gloves (LG) was studied by thermogravimetric analysis. Three methods was used to determine the fraction of reactants and hence the related kinetics parameters. The results of the study indicated that the kinetics parmeters depended on the method of calculation the fraction of reactants. The experimental data at the isothermal temperature 323°C fitted in zeroth, first and second order reaction, and the kinetics of pyrolysis at the isotherm temperature 408°C fitted into first order and second order, depending on the definition of the fraction of reactants. Moreover, the reiteration method was used to find the best value of n and k for thermolysis at both temperatures; the best order for the thermolysis found to be 1.78, and 1.93 at 323 and 408°C, respectively. The activation energy of thermalizes was estimated by two methods: thermal scans, and the plot of k values obtained from five isotherms versus the invers of corresponding temperatures. The value of activation energy for the process at lower temperatures was near to activation energy corresponds to evaporation of volatiles, and at higher temperatures the activation energy was below constituents’ chemical bond energies but it was higher than the reported activation energy for decomposition of polymethyl methacrylate and it was lower than activation energy for decomposition of rubber in tires.