Thermodynamic properties and moisture sorption isotherms four types of natural rubber

Sorption isotherms of natural rubbers were determined at temperatures of 40 to 60°C and in the range of relative humidity varying from 10 to 90%. Six sorption models were used to fit the experimental data. The modified Oswin model was the most suitable model for describing sorption isotherms of all natural rubber types. Thermodynamic properties such as Isosteric heat and differential enthalpy of entropy were determined from moisture sorption data, using the Clausius-Clapeyron equation. The experimental data showed that isosteric heat and enthalpy of sorption was applicable for the moisture sorption behavior of natural rubbers.