1. Reactive ammonium phosphite flame retardant in improving the flame retardancy of air filter paper.
- Author
-
Cheng, Yang, Hui, Lanfeng, Li, Ming, Gao, Yang, Zhao, Mingyue, Chen, Zhixian, and Zhao, Juan
- Subjects
FIREPROOFING ,AIR filters ,FIREPROOFING agents ,FILTER paper ,HEAT release rates ,AMMONIUM ,CELLULOSE nanocrystals - Abstract
To reduce the fire risk of air filter paper, a reactive ammonium phosphite flame retardant was synthesized and applied to the flame-retarding treatment of air filter paper. It was found that ammonium phosphite reacted with cellulose existing in filter paper fibers to form P–O–C bonds and remarkably improved the flame-retarding properties and thermal stability of the air filter paper. After modification of the air filter paper with 30 wt% of ammonium phosphite, its limiting oxygen index value reached 39.5%, which remained at 29.6% after 4 h of the dipping test. The heat release rate and total heat release rate of the treated air filter paper decreased significantly, and the carbon residual amounts at 700 °C in the nitrogen atmosphere and in air reached 43.96% and 16.35%, respectively. During thermal decomposition, ammonium phosphite played a flame-retarding role in both condensed and gas phases. Moreover, ammonium phosphite, as a flame retardant, had no obvious influence on the physical properties and filtration performance of the air filter paper. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF