Cellulose-based composite thermal-insulating foams toward eco-friendly, flexible and flame-retardant. (1st December 2021)

• Record Type: Journal Article
• Authors: Jiang, Shuai; Zhang, Meiling; Li, Mengmeng; Zhu, Jianhua; Ge, Aixiong; Liu, Lifang; Yu, Jianyong
• Is Part Of: Carbohydrate polymers. Volume 273(2021)
• Publication Date: 2021-12-01
• Subjects: Cellulose nanofibril -- Sodium alginate -- Foam -- Flexible mechanical properties -- Thermal insulation -- Flame-retardant; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2021.118544
• Languages: English
• ISSNs: 0144-8617

Abstract

Abstract: Cellulose nanofibrils (CNFs) have been developed as building blocks for highly porous foams which are superior in thermal insulation. Unfortunately, the flammability and poor mechanical performance of CNF foams limited their practical applications. In this strategy, biopolymer sodium alginate, together with nontoxic boric acid and borate, were explored to play the roles of flame retardants for methyltrimethoxysilane cross-linked CNF foams. Their co-effects on preventing CNF foams from being ignited were revealed. The composite foams were self-extinguish and showed a considerably increased limited oxygen index (up to 39.5%). Additionally, the foams were flexible with good resilience and bendability. The eco-friendly foams with low thermal conductivity (0.028 W m −1 K −1 at 25 °C), flexibility, and non-ignitability can meet the satisfactory in energy-conservation, wide applicability, and use safety. Graphical abstract: Unlabelled Image Highlights: A new strategy in improving the practical use of CNF-based foam was investigated. Cellulose composite foam with excellent flame-retardant property was fabricated. Alginate with boric acid/borate played a synergistic role in resisting CNF flaming. The resultant foams showed good compressive resilience and bendability.