Étude théorique et expérimentale de la compatibilisation et de la fissuration sous contrainte environnementale dans les mélanges de polypropylène et de polyéthylène basse densité

Abstract

This thesis investigates the impact of SEBS and SEBS-g-MA as compatibilizers for polypropylene (PP) and low-density polyethylene (LDPE) blends, along with the influence of IGEPAL CA 630 on environmental stress crack resistance (ESCR). The study involves theoretical calculations using molecular dynamics, and experimental analyses such as X-ray diffraction, differential scanning calorimetry, thermogravimetry, and scanning electron microscopy. The addition of SEBS and SEBS-g-MA enhances the morphological and interfacial adhesion of the blends, reducing carbonyl group absorption and improving rupture time in ESCR tests. Molecular dynamics simulations and density functional theory confirm the compatibilizing effects of SEBS and SEBS-g-MA. The inclusion of SEBS-g-MA particularly enhances flexibility and ESCR performance in PP/LDPE blends with specific weight fractions, suggesting that compatibilizers can enhance the properties of these blends in various applications.