PYROLYSIS KINETICS ANALYSIS OF THE POLARIZING FILM FROM WASTE LIQUID CRYSTAL DISPLAY UNDER NON-ISOTHERMAL CONDITIONS

To better understand the pyrolysis process of polarizing film and to supply theoretic guidance for operating condition optimization, the pyrolysis kinetics of polarizing film was analyzed under inert conditions. Experiments were conducted by a thermogravimetric analyzer with heating rates of 5 K/min, 10 K/min, 15 K/min and 20 K/min. Based on the TG-DTG curves, the thermal decomposition characteristics of polarizing film were analyzed. The apparent activation energy and reaction order were evaluated based on Starink approach and Avrami theory. In the range of conversion fraction investigated (20%-80%), the apparent activation energy of polarizing film pyrolysis initially decreased from 158.8 kJ/mol to 140.0 kJ/mol and then increased to 152.4 kJ/mol afterward. Based on the Avrami theory, the reaction order varied from 0.790 to 1.215 at the temperature range of 565 K-585 K, indicating that the pyrolysis of polarizing film is not first-order reaction during its major mass loss stage.