La/Ce-doped Mg-LDH for simultaneous cold resistance and plasticizer migration suppression of PVC in high-altitude environments

Abstract

Flexible Polyvinyl chloride (PVC) utilized in high-altitude, cold regions is frequently constrained by severe plasticizer migration, poor low-temperature toughness, and biosafety risks. Traditional modifiers such as SiO₂, CaCO₃, and conventional layered double hydroxides (LDHs) fail to simultaneously address these challenges; moreover, most LDH-related studies focus predominantly on flame retardancy and thermal stability rather than low-temperature flexibility and anti-migration performance. To address these research gaps, we synthesized La/Ce co-doped magnesium-based LDH(n(La/Ce) via co-precipitation and utilized it as a single functional filler to modify DOTP-plasticized PVC. A systematic evaluation encompassing mechanical tests, migration measurements, low-temperature Raman characterization, and biosafety assessments was conducted. The results demonstrate that the (n(La/Ce) = 1:3/PVC composite exhibits an elongation at break of 456.1% at − 40 °C, while the (n(La/Ce) = 3:1/PVC counterpart achieves a 100% low-temperature impact pass rate alongside a remarkably low plasticizer migration rate of 1.2%. This filler effectively suppresses cold-induced plasticizer phase separation, and comprehensive evaluations confirm the non-toxicity of all modified materials. Furthermore, the optimal filler ratio was determined using response surface methodology. Despite these findings, certain limitations remain: this study only performed single low-temperature simulation tests, without exploring material performance under multi-field coupling and long-term aging conditions characteristic of plateau environments. Future work will focus on field exposure and multi-environmental aging tests. Overall, this work provides a green and feasible strategy for developing high-performance PVC materials tailored for harsh high-altitude environments.