Thermal degradation of recycled polypropylene toughened with elastomers

摘要

Commercial polyolefins, such as polypropylene (PP), are widely used because of their easy processing and their excellent properties. Although their recycling is well established, the mechanical and thermal properties of the recycled products are normally lower than those of the virgin material. The introduction of an elastomeric additive can improve the toughness, without compromising the processability and recycling capabilities. However the thermal properties of these blends should be assessed in order to limit degradation during recycling. This work presents a study of the thermal degradation of blends based on recycled PP with different elastomeric systems. Thermogravimetric analysis in dynamic and isothermal modes is used to develop a kinetic model for the decomposition reaction of the studied blends. The effect of the introduction of the elastomer is analysed through the variation of the apparent activation energies as well as the reaction order and pre-exponential factor. The correspondence between experimental and calculated results demonstrates the validity of the proposed model.