Preparation And Properties Of Polymethyl Methacrylate-coated Halogenated Hydrocarbon Microcapsules Fire Extinguishing Agent

Halogenated hydrocarbon fire extinguishing agent has the advantages of high fire extinguishing efficiency,non-conductive,stable chemical performance,no pollution and no damage to the victim.It is a widely used high-efficiency fire extinguishing agent.At present,most of the halogenated hydrocarbon fire extinguishing agents have some disadvantages,such as complex equipment,strict technical requirements,high injection pressure and inconvenient storage,movement and carrying.Microencapsulation of halogenated hydrocarbon fire extinguishing agent is an important method to solve the above problems.When the microencapsulated fire extinguishing agent reaches a predetermined temperature,the shell of the microencapsulated fire extinguishing agent bursts and releases fire extinguishing gas.When the fire-fighting gas contacts the open fire or the shade burning surface,the fire-fighting gas can quickly and effectively extinguish the fire,so as to automatically start and extinguish the fire.In this paper,with polymethylmethacrylate(PMMA)as wall material,Freon114B-2 or1,1,1,2,2,3,4,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane(DMTP)as core material,PMMA/Freon114B-2 and PMMA/DMTP microcapsule fire extinguishing agents were prepared by suspension polymerization.The morphology,loading capacity,structure and fire extinguishing performance of PMMA/Freon114B-2 and PMMA/DMTP were studied.The main works are as follows:(1)Preparation of PMMA/Freon114B-2 microcapsule fire extinguishing agent:PMMA/Freon114B-2 microcapsule fire extinguishing agent was prepared with PMMA as wall material and Freon114B-2 as core material.The effects of emulsifier selection,initiator selection,emulsifier dosage,initiator dosage,core wall ratio and stirring speed on the morphology and loading capacity of microencapsulated fire extinguishing agent were studied,and the optimal preparation conditions were optimized.The microencapsulated fire extinguishing agent prepared under the optimum conditions is spherical,well dispersed and uniform in size,with a loading capacity of 45.7%.FTIR results showed that PMMA coated Freon114B-2 by physical action.TG results showed that the fire extinguishing agent could be released from the microcapsules in the temperature range of 110-400 ?.The stability test results show that the microencapsulated fire extinguishing agent can be stored stably at room temperature.The experimental results show that PMMA/Freon114B-2 microcapsule can extinguish the flame in a short time.(2)Preparation of PMMA/DMTP microcapsule fire extinguishing agent:PMMA/DMTP microcapsule fire extinguishing agent was prepared with PMMA as wall material and DMTP as core material.The effects of emulsifier selection and dosage,initiator dosage,core wall ratio and stirring speed on the morphology and loading capacity of microencapsulated fire extinguishing agent were studied,and the preparation conditions were optimized.The results show that the microencapsulated fire extinguishing agent prepared under the optimum conditions has regular ball shape,uniform size and good dispersibility,and the loading capacity is 51.3%.FTIR results showed that PMMA and DMTP were coated by physical interaction.TG results show that the fire extinguishing agent can be released in the temperature range of 120-400 ?.The stability test results show that the microencapsulated fire extinguishing agent can be stored stably at room temperature.The experimental results show that the microencapsulated fire extinguishing agent can extinguish the flame in a short time.In this paper,two kinds of halogenated hydrocarbon microencapsulated fire extinguishing agents are studied,which have wide application prospects in the field of fire fighting.