Experimental Study on Thermosensitive Hydrogel Used to Extinguish Class A Fire.

Li Ma,Xixi Liu,Xiao Huang,Gaoming Wei,Youjie Sheng

doi:10.3390/polym13030367

Abstract

Hydrogels are crosslinked polymers that become fully swollen when placed in aqueous environments. They are widely used in the field of firefighting because they can remarkably increase the viscosity and wettability of water. In this study, a thermosensitive hydrogel used to effectively suppress class A fire was synthesized by using methylcellulose, sodium polyacrylate, and magnesium chloride. The structure, surface activity and viscosity of the hydrogel were characterized. Fire extinguishing performance was evaluated based on small-scale and large-scale experiments. The results showed that a phase transition of the hydrogel occurred when the temperature rose from 50 °C to 80 °C. After the phase transition, the hydrogel showed a higher viscosity and lower surface tension, which was conducive to attach to the surface of the burning material and acting as an effective barrier to isolate oxygen. The small-scale fire extinguishing tests indicated that the concentration of the hydrogel solution has an eminent influence on fire extinguishing performance. The optimum concentration for extinguishing performance was around 6 wt%. The large-scale experiments demonstrated that the fire-extinguishing performance of this thermosensitive hydrogel was superior to the two other commercial water-based fire extinguishing agents, as it prevented re-ignition highly efficiently.

Highlights

The results revealed that thermosensitive hydrogel exhibited better fire extinguishing performance than ordinary gel and foam extinguishing agents
A type of thermosensitive gel additive was prepared by compounding methylcellulose, sodium polyacrylate, and magnesium chloride
The phase transition occurred when the temperature was higher than 80 ◦ C, the viscosity was notably boosted, and the surface tension was reduced

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Fires often cause extensive wealth loss and pose a momentous threat to human life. Fire extinguishing agents with high-efficient combustion suppression are crucial to prevent fire hazards [1,2,3]. Water is used to cool flames because of its high heat capacity [4], but the strong fluidity of water will cause it to be wasted due to the massive loss in most fire-fighting operations, and improper disposal of fire wastewater can lead to water pollution [5,6]. It is an urgent task to research and develop a new environmentally friendly fire extinguishing agent

Methods

Discussion

Conclusion