Preparation Of Thermosensitive Hydrogel And Experimental Study On Fire Extinguishing Characteristics

Water is one of the most commonly used,fire extinguishing agents for extinguishing Class A fires such as buildings and forests.However,in the process of extinguishing fire,water is easily lost,the use efficiency is low,and a large amount of water lost will cause water damage damage.Various additives are usually added to the water to change the physical properties of the water to improve the fire extinguishing performance of the water.Increasing the viscosity of w.ater is one of the most effective ways,but the conventional polymer hydrogel has the disadvantages of difficulty in transportation and short ejection distance.Based on the problems existing in the fire-extinguishing process of traditional polymer hydrogels,this paper prepared a temperature-sensitive property that is environmentally friendly,easily degradable,has good thermal stability,and can undergo sol-gel phase changes when affected by external temperature changes.Hydrogels.The hydrogel is mainly composed of methyl cellulose(MC),polyethylene glycol(PEG),sodium chloride(NaCl),ammonium polyphosphate(degree of polymerization n=5 and n=30?50)flame retardants.The hydrogel is sol-like at a temperature less than the critical transition temperature(LOST)and has a low viscosity.The utility model overcomes the defects that the common polymer hydrogel has large viscosity and poor fluidity at normal temperature;It is gel-like when it exceeds LCST.It has a high viscosity and combines the advantages of high viscosity and strong adhesion of ordinary polymer hydrogels.In this paper,the effects of different monomer component additions on temperature-sensitive hydrogel LCST,gel time,and viscosity of normal temperature sol and high temperature gel were investigated.Finally,the optimum ratio of concentration is MC:PEG:NaCl:ammonium polyphosphate(degree of polymerization n=30to50)=1.2:5:4:1.2.The structural characteristics and thermal stability of temperature-sensitive hydrogels were studied by TG and FT-IR,and the gel mechanism of temperature-sensitive hydrogels was analyzed.According to the national standard GB4066.2-2008,Class A mule fire extinguishing test bench and 55B oil pool fire extinguishing test bench of different scales were built.The free burning law of wood bonfire was studied,and the characteristics of temperature-sensitive hydrogel under different conditions for class A wood bonfire and class B oil pool fire were studied.The results of firewood A fire extinguishing experiment showed that the fire time increased first and then increased with the increase of temperature sensitive hydrogel mass fraction.The best temperature sensitive hydrogel fire extinguishing concentration was 4%;Temperature-sensitive hydrogels are superior to water and DTE water-based fire extinguishing agents in fire extinguishing performance and re-ignition resistance.The protective properties of water and temperature-sensitive hydrogels on combustibles were compared by cone calorimeter.The experimental results show that the watering and temperature-sensitive hydrogel soaking the pine boards can delay the ignition time of the board and delay the arrival of the board.The time at which the first heat release rate(HRR)peaks,reducing the magnitude of the HRR peak;And the wood treated with the temperature-sensitive hydrogel was ignited for a longer time and reached the first HRR peak time,with more peak reduction.The systematic research work in this paper provides a scientific basis for promoting the development of temperature-sensitive hydrogel fire fighting technology,and has strong academic and engineering application value.