Kinetics and mechanism of Taizhou AH-90 asphalt oxidation

Key words:  asphalt  oxidation  free radical  hydroperoxide  kinetics

Abstract:

With the air flow of 150 L/ (kgK) , asphalt was oxidated in the batch oxidation reactor at 200 ，220X! and 240 respectively, Tlie softening point and infrared spectra of the oxidated asphalt were tested. The softening point and reaction time were fitted by means of Lockwood model, and the relation of softening point and reaction time was obtained. TTic infrared spectra of the oxidated asphalt and the material asphalt were compared. Hie re&ults show that the relation of softening point and reaction time follows the laws of overall first order kinetics. The area of oxidated asphalt carbonyl absorption peak increases greatly when the wavenumber equals 1 698.1 cm-1, and increases with reaction lime. Tlie mechanism of asphalt oxidation belongs to self-oxidation. The initiator of hydroperoxide is produced in process of reaction. The hydroperoxide decomposes and produces the alkoxy free radical. Finaly, the alkoxy free radical comes into being the carbonyl compound.