Résumé: Polylactic acid (PLA) is a biopolyester known for its biodegradability, but its brittleness and poor thermal and barrier properties limit its large-scale commercial applications and restrict its use in many industrial sectors. As a result, significant research has focused on modifying PLA to expand its range of applications for both economic and environmental purposes. In this context, blending PLA with conventional synthetic polymers has emerged as a promising strategy, with particularly notable results when combined with linear low-density polyethylene (LLDPE) and polycarbonate (PC). This study aims to prepare and characterize PLA/PC blends with compositions of 90/10, 70/30, and 50/50 %, incorporating 10% LLDPE to enhance thermal stability, mechanical performance, and viscoelastic behavior. The blends were prepared using an internal mixer and analyzed through differential scanning calorimetry (DSC), torque rheometry, thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) Keywords: Polycarbonate, Linear Low-Density Polyethylene, Polylactic Acid, Blend, Properties

Résumé: A nanocomposite is formed by combining two or more materials at the nanoscale to form a new product that possesses the combined properties of the constituent materials [1]. Due to the larger surface area available with the nanofiller, polymer nanocomposites offer the potential to enhance mechanical properties, particularly the modulus of elasticity, thermal properties, and barrier and flame retardant properties. Polycarbonate (PC) is a thermoplastic polymer widely used in many application areas due to its various properties such as transparency, thermal stability, and impact resistance. The incorporation of nanoparticles into PC has been considered to impart certain mechanical properties such as improved dimensional stability and greater scratch resistance, while maintaining its transparency. However, this increase in rigidity induced by the addition of lamellar phyllosilicate nanofillers causes a loss of polymer deformability, resulting in a decrease in the deformation at break and the resilience of the nanocomposites. Thus, our study aims to improve these mechanical characteristics by incorporating low levels of linear low-density polyethylene (LDPE-L) in order to compensate for the drop in impact strength of PC/organophilic montmorillonite nanocomposites. Given the incompatible nature of the system, we added a 10% level of linear low-density polyethylene grafted with maleic anhydride (LDPE-g-MA). The study of the variations in mixing torque and thermal properties as a function of composition showed that the addition of clay and LPE-LDPE significantly affects the viscosity of the mixture and the glass transition temperature of PC. Furthermore, the mechanical properties of the nanocomposites highlighted the favorable effects induced by the addition of PEBD-L and the compatibilizing agent PEBD-g-MA. Keywords: nanocomposite, polycarbonate, nanofiller, LDPE

Résumé: High-density polyethylene (HDPE) is a polymer widely used in many industrial applications such as manufacture of gas and water pipes. The main objective of this work is to study the influence of carbon black (NC) on the properties of composites based on HDPE TR-402 with different NC rates (0 to 5%) carried out at CP2K SKIKDA complex, ALGERIA, in order to examine the effect of the content of this adjuvant on the quality of HDPE TR-402/NC composites; physical, thermal and mechanical analyzes were carried out. This study shows that the addition of carbon black improves some properties of the composite, including viscosity index, hardness, yield strength, and fracture toughness. However, 2.5% by weight rate of NC gives the best characteristics to this grade of HDPE. Keywords: High density, polyethylene, additives, polymer, composite, carbon black.