Lei Xia,Tianyi Lu,Miqiu Kong,Jingke Pei,Yajiang Huang,Yanhua Niu,Yadong Lv,Guangxian Li
Despite extensive research on the impact of environmental weathering on the degradation of electromagnetic wave absorbing (EWA) coatings, the influence of material composition on their service stability remains underexplored. In this study, we prepared EWA coatings with epoxy resin as the matrix and flaky carbonyl iron (FCI) as the absorber, at concentrations of 50 wt%, 60 wt%, and 70 wt%. These coatings underwent a 192-h combined UV irradiation-salt spray accelerated aging test to examine the effects of varying absorber concentrations on their corrosion behavior and mechanisms. Surface morphology, chemical structure evolution, and corrosion diffusion were analyzed using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDX). Corrosion behaviors and their impact on wave absorption performance were further investigated using electrochemical impedance spectroscopy (EIS) and electromagnetic simulations. Our results show that increasing FCI content accelerates the corrosion rate of the composite coating. This acceleration is attributed to the reduced protective effect of the epoxy matrix at higher FCI concentrations and the defects caused by FCI corrosion, which facilitate the penetration of corrosive media. This study elucidates the influence of varying absorber concentrations on the weather resistance of the coatings and their microscopic mechanisms, providing valuable insights for optimizing the service stability of EWA coatings.
Lu Gaojun,Zhu Jingli,Yu Houyong,Jin Meijin,Abdalkarim Somia Yassin Hussain,Wei Yong
Oceans and soils have been contaminated with traditional plastic due to its lack of degradability. Therefore, green biopolymer composites reinforced with cellulose nanocrystal-zinc oxide hybrids (ZnO hybrids) with good biodegradation ability provided a positive impact on reducing environmental challenges. In this work, the effect of various morphologies of ZnO hybrids on the biodegradation ability of poly(butylene adipate-co-terephthalate), PBAT) under seawater, soil burial, and UV aging conditions were investigated. Sheet-like ZnO hybrids (s-ZnO hybrid) efficiently enhanced the mechanical, UV-blocking properties and biodegradation ability of PBAT nanocomposite films. Compared to neat PBAT, the best tensile strength of PBAT nanocomposite with 2 wt% s-ZnO hybrid was increased by 15.1%, meanwhile this nanocomposite films showed the highest biodegradation rate after 80 days of soil degradation and 90 days of seawater degradation. Besides, three possible biodegradation mechanisms of green PBAT nanocomposite films were presented, hinting that such PBAT nanocomposite have great promising packaging applications. Graphic abstract
危险品化学品经营许可证（带存储）