Thermomechanical properties of polypropylene and styrene-ethylene-butylene-styrene blends: a molecular simulation and experimental study

Résumé : Polymer blends consisting of two or more polymers are important for a wide variety of industries and processes, but, the precise mechanism of their thermomechanical behaviour is incompletely understood. In order to understand clearly, it is essential to determine the miscibility and interactions between the components in polymer blend and its macroscopic thermomechanical properties. In this study, we performed experiments on SEBS and isotactic PP blends (SP) as well as molecular dynamics simulations, aiming to know the role played by molecular interactions on the thermomechanical properties. To investigate the glass transition temperature (Tg) of SEBS, PP and their blends at different ratio, the unit cell of the polymer molecular structure of each was established. The LAMMPS molecular dynamics method was used to predict the density, specific volume, free volume, enthalpy, kinetic energy, potential energy and bond energy. The (Tg) s of the SEBS, PP and SP blends were predicted by analysing these properties. Interestingly, the simulated values of the Tg of SEBS, PP and their blends showed good agreement with our experimental results obtained from dynamic mechanical analysis (DMA). This technique used in this work can be used in studying glass transition of other complex polymer blends.