Highly flexible cross-linked cellulose nanofibril sponge-like aerogels with improved mechanical property and enhanced flame retardancy

Limin Guo; Zhilin Chen; Shaoyi Lyu; Feng Fu; Siqun Wang

doi:10.1016/j.carbpol.2017.09.084

Highly flexible cross-linked cellulose nanofibril sponge-like aerogels with improved mechanical property and enhanced flame retardancy

Carbohydr Polym. 2018 Jan 1:179:333-340. doi: 10.1016/j.carbpol.2017.09.084. Epub 2017 Sep 27.

Authors

Limin Guo¹, Zhilin Chen², Shaoyi Lyu¹, Feng Fu¹, Siqun Wang³

Affiliations

¹ Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, China.
² Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, China. Electronic address: chenzhilin@caf.ac.cn.
³ Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, China; Center for Renewable Carbon, University of Tennessee, Knoxville, TN 37996, USA. Electronic address: swang@utk.edu.

PMID: 29111059
DOI: 10.1016/j.carbpol.2017.09.084

Abstract

Cellulose nanofibril (CNF) aerogel is highly flammable and its mechanical strength is very soft, which is unfavourable due to safety concerns and impractical when used as the thermal insulation material. In this work, we used N-methylol dimethylphosphonopropionamide (MDPA) and 1,2,3,4-butanetetracarboxylic acid (BTCA) as co-additives and then prepared lightweight flame resistant CNF sponge-like aerogels via an eco-friendly freeze-drying and post cross-linking method. The CNF/BTCA/MDPA aerogel exhibited a better flame retardant performance, outstanding self-extinguishing behaviour and significantly increased char residue (by as much as 268%) compared with the neat CNF aerogel. Meanwhile, the resilience of the aerogel samples improved significantly as the flexibility decreased slightly. Furthermore, the aerogel samples still exhibited excellent thermal insulating properties with thermal conductivity as low as 0.03258W/(m k). The combination of these characteristics makes the CNF-based aerogel a promising insulation candidate for thermal protective equipment (e.g., fire-protection clothing or advanced spacesuit elements) in the future.

Keywords: Aerogel; Cellulose nanofibril; Cross-linking; Flame retardant; Resilience.