Catalytic degradation of low-density polyethylene and polypropylene using modified ZSM-5 zeolites

Abstract

The catalytic degradation of low-density polyethylene (LDPE) and polypropylene (PP) using a modified ZSM-5 zeolite, DeLaZSM-5, has been investigated. The results obtained have been compared with those of USY, ZSM-5, and also thermal degradation. The degradation behaviours of LDPE and PP using DeLaZSM-5 were quite different from those observed in thermal degradation and in studies using USY as catalysts. LDPE exhibited much higher degradation activity using the DeLaZSM-5 than PP did, especially in relatively lower temperature stage, indicating that DeLaZSM-5 shows a shape-selective effect in catalytic degradation of LDPE and PP. The factors affecting the shape-selective effect of DeLaZSM-5 are discussed. It was concluded that the pore structure and unique acid properties of the DeLaZSM-5 as well as proper reaction temperatures were important factors to fully exert this shape-selective effect.