Multifunctional Stabilization of TPU / POSS ‐ HALS ‐Silane Hybrid Nanocomposites for Enhanced Env

ABSTRACT

Thermoplastic polyurethane (TPU) envelope materials used in lighter‐than‐air (LTA) vehicles are susceptible to degradation from ultraviolet radiation, ozone exposure, heat, and humidity, leading to deterioration in mechanical performance and service life. In this study, TPU‐based hybrid nanocomposites containing 3 wt.% octamethyl polyhedral oligomeric silsesquioxane (OMP‐POSS), bis (2,2,6,6‐tetramethyl‐4‐piperidyl) sebacate (HALS), and 3‐mercaptopropyl trimethoxy silane (MPTMS) were developed and optimized to improve environmental durability. The influence of HALS and MPTMS loading on thermal stability, morphology, viscoelastic behavior, and aging resistance was systematically investigated. The optimized formulation U2S0.9 exhibited the highest thermal stability, with an onset degradation temperature of 239.5°C compared to 184.4°C for the control TPU. FTIR analysis and depth profiling revealed that aging‐induced chemical modifications were primarily confined to the exposed surface, while the siloxane‐rich interfacial structure remained preserved within the bulk. Mechanical retention studies demonstrated superior aging resistance, with U4S0.9 exhibiting tensile strength retention of 133.3% and 158.3% after accelerated weathering and ozone aging, respectively. The hybrid stabilization effects of HALS, MPTMS, and OMP‐POSS effectively suppressed environmental degradation, demonstrating the potential of these hybrid nanocomposites as durable protective envelope materials for aerostat and LTA vehicle applications.