Robust and highly resilient waterborne polyurethane-based composite aerogels prepared by blending with aramid nanofibers. (29th September 2022)

• Record Type: Journal Article
• Authors: He, Ran; Xie, Chunjie; Chen, Yuexi; Guo, Zhao-Xia; Guo, Baohua; Tuo, Xinlin
• Is Part Of: Composites science and technology. Volume 228(2022)
• Publication Date: 2022-09-29
• Subjects: Waterborne polyurethane -- Aramid nanofiber -- Composite aerogel -- Resilience; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2022.109622
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Robust waterborne polyurethane (WPU)-based composite aerogels have a promising prospect of application. However, their preparation is still challenging. Herein, polymerization-induced aramid nanofibers (PANFs) were used to reinforce WPU aerogel by taking the advantage of their intrinsic rigidity and the hydrogen bonding interaction between WPU and PANFs. The WPU/PANF composite aerogels containing 0–10% PANFs were prepared by a simple mixing and freeze-drying technique. The composite aerogels exhibit super-flexibility and excellent processability. The specific compressive strength of the composite aerogels shows an increasing tendency with PANF content. By incorporating 10% PANFs, the compressive strength of the aerogel (WF-10%) reaches 335.1 kPa at 70% strain, which is 742% larger than that of neat WPU aerogel with similar porosity. Cyclic compression tests show that the aerogels have excellent durability with a strain recovery of about 95%. After long-term compressive stress, the WPU/PANF composite aerogels have much better resilience than neat WPU aerogel with similar porosity. In simple burning tests, a continuous char layer was formed on the combustion surface of WF-10%, preventing further combustion. Graphical abstract: Image 1 Highlights: Robust and highly resilient composite aerogels were prepared by blending waterborne polyurethane with aramid nanofibers using a freeze-drying technique. The introduction of aramid nanofibers significantly enhances compressive strength and resilience, and slows down the combustion rate of composite aerogels. The composite aerogels exhibit super-flexibility, excellent processability and good thermal insulation ability. The outstanding fatigue resistance with the best recovery ability and excellent compressive resilience endow composite aerogels a great potential in applications as supportive and comfortable seating and cushioning materials.