This study investigates the influence of zinc oxide (ZnO) nanoparticles on the mechanical, thermal, and surface properties of low-density polyethylene (LDPE) nanocomposites under accelerated weatheringconditions, including UV exposure, elevated temperature, and humidity. LDPE samples were reinforced with varying ZnO concentrations (0.5%, 1%, and 2%) and compared to neat LDPE (D0). Shore D hardness and Charpy impact tests showed enhanced mechanical stability in nanocomposites, with D1 (0.5% ZnO) exhibiting improved hardness and impact resistance before and after exposure. Contact angle measurements indicated increased hydrophobicity in D1 due to better dispersion of ZnO. At the same time, higher loading in D2 led to a decrease in contact angle due to surface roughness and nanoparticle agglomeration. SEM analysis supported these findings, revealing smoother, defect-free surfaces in D1 compared to D0. Thermal analysis via TGA and DSC demonstrated that D1 had superior thermal stability, with delayed degradation onset (432.8°C), reduced weight loss (89.18%), and higher enthalpy values (ΔH₂ = 136.7 J/g). In contrast, D3 (2% ZnO) showed increased degradation and instability due to excessive nanoparticle aggregation. Overall, the incorporation of 0.5% ZnO proved optimal, balancing mechanical reinforcement, thermal durability, and surface performance, making it a promising candidate for outdoor applications such as irrigation piping.
