Catalytic degradation of low and high density polyethylenes using ethylene polymerization catalysts: Kinetic studies using simultaneous TG/DSC analysis

In this work, the catalytic degradation of high and low density polyethylenes, using catalysts based on transition metals supported on zeolite Y, is analysed using simultaneous thermogravimetry (TG) and differential scanning calorimetry (DSC). The results obtained in the catalytic degradation are compared with those that were obtained in the purely thermal degradation. The transition metals used, vanadium, zirconium and nickel, supported on NaY or HY were studied since they were found to be active, although with different degrees of efficiency, for ethylene polymerization, which is, in a way, the reverse reaction of the one we are interested in. It was found that they are also able to promote the degradation process of polyethylene, also with varying efficiencies. A kinetic model capable to describe the performance of the catalytic degradation, and which has already been used to analyse its thermal degradation, has been applied. Fitting this model to the experimental results obtained by TG and DSC made it possible to estimate several kinetic parameters and to gain some insight into the processes involved.

Graphical abstractThe catalytic degradation of polyethylene, using catalysts based on transition metals supported on zeolite Y, is analysed using simultaneous TG/DSC. These catalysts were active for ethylene polymerization, the reverse reaction of the one we are interested in. They were also able to promote the degradation process of polyethylene. A kinetic model was used to provide insight into the processes involved.Figure optionsDownload full-size imageDownload high-quality image (89 K)Download as PowerPoint slide