Synthesis and performance characteristics of organic-inorganic hybrid fire prevention and extinguishing gel based on phytoextraction-medical stone

Abstract

This study is aimed at lowering material costs and meanwhile achieving cleaner production by making full use of peanut shells, a kind of agricultural waste. To this end, cellulose nanofibrils (CNF) extracted from peanut shells were mixed with 2-acrylamide-2-methylpropanesulfonic acid (AMPS), medical stone (MDS) and acrylic acid (AA) for preparing biodegradable AA-AMPS-CNF/MDS gel for fire prevention and extinguishing (FPE). The experimental results show that the optimal water absorption rate and salt resistance performance of the prepared AA-AMPS-CNF/MDS FPE gel are achieved under the CNF: AMPS: MDS: AA ratio of 2: 1: 0.3: 14, the crosslinking agent amount of 1.8% and the initiator amount of 2.5%. The infrared spectroscopy and X-ray diffraction analysis results suggest that MDS, AA, AMPS and CNF have experienced copolymerization which leads to the formation of an amorphous structure. The scanning electron microscopy analysis results demonstrate that the product has an orderly three-dimensional structure containing voids on the whole, and elements in it are highly uniformly and densely distributed. Relevant test experiments show that the product has high water absorption and salt resistance. Through Hartmann tube test and inhibition performance test, as well as the combustion HRR curve of coal samples, the proposed FPE gel and mixed products, it is proved that the product has superior flame retardant effect. In addition, the effect and mechanism between the proposed FPE gel and coal is rarely reported in related researches. In this study, the proposed FPE mechanism and wetting effect of AA-AMPS-CNF/MDS are explained by means of molecular dynamic simulation (MS) simulation, which agrees with the above experimental results. The proposed FPE gel can effectively inhibit coal oxidation and lower coal temperature, thus protecting the physical and mental health of coal workers. In general, this research is of crucial economic and social benefits.