Fabrication of rigid flame retardant foam using bio-based sucrose-furanic resin for building material applications

As sucrose is less expensive and more readily available than tannin, sucrose-based foams were prepared by incorporating furfuryl alcohol (FA) and glyoxal as a crosslinking agent to obtain sucrose-furan-glyoxal (SFG) resin. Ammonium dihydrogen phosphate (ADP) was then incorporated into SFG and foamed with azodicarbonamide (AC) to form SFGA foam. The study examined the chemical structures, morphology, mechanical properties, thermal properties and flame retardancy of the foams. The findings indicated that the SFGA foam exhibited a closed cell structure characterized by a smooth surface as well as high compressive strength and shore hardness. The closed structure of SFGA provides the foam with good thermal stability and excellent flame retardancy, as demonstrated by its limiting oxygen index (LOI) of 43.3 %. The combustion test demonstrated that the SFGA foam attained the UL-94 V-0 flame retardant classification. During the process of combustion, the primary volatile compounds identified were carbon dioxide, acetic acid, and oxanes. No toxic substances such as alkanes were detected. In addition to its outstanding flame retardant properties, SFGA foam is also capable of biodegradation. After being buried in soil for 30 days, it exhibited a weight reduction of 2.7 %. The SFGA foam underwent a weight reduction of 0.69 % in the laboratory when exposed to Penicillium sp for a duration of 20 days. The study proposed that sucrose can serve as a substitute for tannin in the production of rigid foam, which is suitable for insulation materials.