Performance of birnessite-type manganese oxide in the thermal-catalytic degradation of polyamide 6

Abstract

Birnessite-type manganese oxide (BMO) was prepared by oxidation of Mn(NO3)2 with H2O2 in KOH solution. The nature and the extent of degradation of polyamide 6 (PA6) in the presence of samples were analysed by thermogravimetric analysis under static air atmosphere at several heating rates between 5 and 30 °C min−1. The surface and structure of BMO were characterized using infrared (IR) spectroscopy, X-ray diffraction, and thermal analysis techniques. The acid sites of BMO were investigated by IR using pyridine as a molecular probe. The activation energy for degradation estimated by Kissinger method for PA6 and BMO/PA6 system containing 10 mass% of BMO was found to be 212 and 144 kJ mol−1 under air, respectively. The catalytic activity observed in BMP catalyst was associated to a high lattice oxygen mobility.