China Safety Science Journal ›› 2022, Vol. 32 ›› Issue (5): 127-133.doi: 10.16265/j.cnki.issn1003-3033.2022.05.0114

• Safety engineering technology • Previous Articles     Next Articles

Preparation and flame retardant properties of silica gel foam

GONG Yawen(), LIU Yingchun, JING Mingju, ZHANG Yingnan, ZHANG Bin   

  1. College of Safety Science and Engineering, Nanjing Tech University, Nanjing Jiangsu 211816, China
  • Received:2021-12-18 Revised:2022-03-25 Online:2022-08-17 Published:2022-11-28

Abstract:

In order to solve problems of low viscosity and poor stability of silica gel foam materials, a silica gel foam was prepared by using composite foaming agent, foam stabilizer, sodium silicate solution and acetic acid as raw materials. Firstly, sol-gel method and orthogonal test were used to study properties of sodium silicate solution's crosslinking system and compound foaming agent. Secondly, gelling time and viscosity of gels at different proportions were tested by Brookfield viscometer, and gel ratio suitable for solid combustibles (wood) was selected. Subsequently, on-site experiments were conducted by utilizing synchronous thermogravimetric (TG) analyzer to study flame retardant properties of gel foam on wood. The results show that silica gel foam has good flame retardant effect on wood combustion. The gel could be bonded to surface of solid combustibles (wood) during gelation process. In air atmosphere, carbon residue rate of wood is almost zero, while that for wood @gel foam system after experiment is about 48.63%, and according to the field wood burning tests, the wood's weight loss rate is 46% higher than gel-treated wood, indicating that the gel foam has better flame retardancy.

Key words: silica gel foam, flame retardancy, thermogravimetric(TG), thermal stability, gelation time