Preparation of NiP@Fe-SBA-15 Suppressant and Its Inhibition Mechanism on PP Dust Deflagration Flames

Polypropylene (PP) is a widely utilized plastic material in industrial production. However, during its production and transportation, it is highly prone to dust explosion accidents, posing significant threats to personnel and equipment safety. In this study, a novel explosion suppressant NiP@Fe-SBA-15 was synthesized to suppress the propagation of PP dust combustion flames. The synthesis method employed was in situ, whereby SBA-15 mesoporous silica was modified with metal ions, followed by the loading of active components NiP to prepare NiP@Fe-SBA-15.The results of SEM-Mapping test indicated that the active elements were uniformly distributed without significant aggregation, ensuring good dispersibility of the suppressant. In this paper, Hartman explosive device was used to evaluate the effect of NiP@Fe-SBA-15 explosion suppressor on PP dust deflation. The experimental results show that with the increase of NiP@Fe-SBA-15 additive, the flame propagation rate of PP dust deflagrator decreases significantly, and the flame propagation is almost completely inhibited when 70wt% inhibitor is added. The double explosion suppression mechanism of NiP@Fe-SBA-15 inhibiting the deflagging of PP dust is analyzed. On the physical level, NiP@Fe-SBA-15 inhibitor occupies the reaction space and reduces the concentration of oxygen and combustible volatiles, thus limiting the combustion reaction. At the same time, the SBA-15 molecular sieve exposed by thermal decomposition of the suppressor absorbs heat by forming a physical barrier, thus reducing the intensity of the combustion reaction. At the chemical level, the active ingredients NiP and Fe groups capture the living free radicals (H·, O·, OH·) produced during combustion, effectively interrupting the chain reaction and reducing the intensity of the explosion. In summary, this study proves that NiP@Fe-SBA-15 is an effective explosion suppressor for PP dust explosion, and reduces the combustion intensity of PP dust by combining physicochemical synergies. The research results of this paper can provide a new idea and method for improving the safety of polypropylene industry. Future research will focus on optimizing the application of NiP@Fe-SBA-15 explosion suppressors in industry, while solving the problems of cost, environmental sustainability and stability, so as to further promote the dust explosion prevention technology.