Strong ultralight foams based on nanocrystalline cellulose for high-performance insulation

• Published in: Carbohydrate polymers 2019-08, Vol.218 (C), p.103-111
• Main Authors: Wang, Peipei, Aliheidari, Nahal, Zhang, Xiao, Ameli, Amir
• Format: Article
• Language: English
• Subjects: Foam; MATERIALS SCIENCE; Mechanical properties; Nanocrystalline cellulose; Polyvinyl alcohol; Thermal insulation; Ultralight
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2019.04.059

[Display omitted] •NCC-based composite foams is fabricated through a simple process.•Ester and hydrogen bonds contribute to enhanced mechanical properties.•More uniform cellular structure is obtained in composite foams.•Foams exhibit excellent elasticity and strength, superior to pure NCC foam.•Foams are ultralight with low conductivity suitable for insulation applications. Environmentally friendly, sustainable, and high-performance thermal insulators are in high demand. Petroleum-based insulator foams usually have high thermal conductivity and pose health hazards. Here, we report ultralight composite foams that are highly strong, elastic, and super-insulating. The foams are composed of nanocrystalline cellulose (NCC) (74 wt%), polyvinyl alcohol (7.5 wt%), and a crosslinking agent (18.5 wt%). The fabrication process is simple and uses only water. The composite foams exhibit an elastic strain of ˜13% at a modulus of 250 K Pa and a stress of 73 K Pa at 50% strain (100+ and 18 times, respectively, higher than those of pure NCC foam); both exceed the values of reported nanocellulose-based foams with no reinforcement. The foams exhibit a thermal conductivity of 0.027 Wm−1 K−1, which is superior to those of traditional insulating materials. The structural integrity is also preserved after burning. Our results show that NCC-based materials can be engineered towards high-performance insulation applications.