IMPROVED QUANTITATIVE-DETERMINATION OF ELASTOMERS IN TIRE RUBBER BY KINETIC SIMULATION OF DTG CURVES

A method of identifying and quantifying elastomers and processing oil in tire rubber, called DTG curve simulation method, is proposed. This method is based on DTG (derivative thermogravimetry) analysis of the straight elastomers NR, BR and SBR, which produces a series of decomposition rate data and pairs of kinetic constants. DTG curves of binary elastomer systems NR/SBR, NR/BR and BR/SBR are measured. The samples are qualitatively identified following the shape of their DTG curves. Quantitative determination is achieved by DTG curve simulation using a least squares method. When correct elastomers and proper compound ratio are chosen, minimum simulation error is achieved leading to effective identification. Satisfactory results were obtained when applying the method to elastomer mixtures of known composition and to tire rubbers of unknown composition. The study advanced the capability of the TG-DTG technique for quantitative determination of elastomers and blends.