Stearate and hindered amine light stabilizers coordinate to boost charge storage performance of water electret melt-blown nonwovens

Water electret (WE) technology is a current research hotspot in the field of high-efficiency and low-resistance melt-blown filter materials. The electret is an important factor affecting the filtration performance and dura-bility of WE melt-blown nonwovens. In this paper, WE melt-blown nonwovens were prepared with stearate compounded with hindered amine light stabilizer (HALS) as the electret additives, which exhibited excellent performance and the filtering efficiency of DEHS oily particles exceeding 99%. The charge formation and storage mechanism of WE melt-blown nonwoven were also elucidated by using the thermally stimulated discharge technique. Benefiting from the inherent amino group of HALS and the synergistic effect with stearate, positively charged hydrated protons were attracted and migrated to the interior of the fiber to form durable space charges, which led to a significant enhancement of the filtration/charge storage performance of melt-blown nonwoven. The charge stability performance of WE melt-blown nonwoven was also investigated under the treatment of solvents such as constant temperature and humidity, high-temperature hot water, alcohol, and isopropyl alcohol. These studies help to improve the product quality of WE melt-blown nonwovens, as well as provide a systematic guide to an in-depth understanding of the electret mechanism of WE technology.