| With the continuous development of marine military,the role of underwater detection technology is becoming more and more important.Therefore,higher requirements are put forward for underwater acoustic materials.For example,as the diving depth of submarines continues to increase,acoustic materials are required to have better resistance.Pressure performance,so as to maintain stable acoustic performance in a constantly changing environment.Rubber and water are easier to match the characteristic acoustic impedance,coupled with the viscoelasticity of rubber,it is widely used in the field of underwater acoustics.In this paper,starting from the base rubber,through different levels of formulation design,processing and testing to explore the relationship between rubber material structure and acoustic properties,and prepared three kinds of rubber nanocomposites with better compressive effects.The main research content Including the following aspects:(1)The sound absorption,sound transmission,and sound insulation mechanisms of acoustic materials are explained and analyzed.Through the acoustic mechanism,it can be known that the modulus and self-loss of rubber materials are closely related to their acoustic performance.Therefore,this paper chooses two types of rubber,low modulus and high loss nitrile rubber and high modulus,low loss eucommia rubber,from the four levels of cross-linking density,filler compounding,rubber blending,and fiber compounding.The formulation design of different material structures is carried out to explore the relationship between material structure and acoustic performance.(2)Tested and analyzed the crosslinking density of nitrile rubber and eucommia ulmoides and its mechanical and acoustic properties.It is found that the crosslinking density has a greater impact on the glass transition temperature,tensile strength and other mechanical properties of the material,but it has a great impact on the sound absorption.The impact of transmission and reflection is small;after adding carbon black on the basis of vulcanized nitrile rubber,the transmission coefficient reaches above 0.8,and it remains consistent under all pressures.The water pressure resistance depth exceeds 300m.Further introduce glass beads,coupling agent,and oxidation the aluminum filler verifies that the surface friction of the filler plays a leading role in improving the sound absorption performance.(3)Using eucommia gum as a carrier,the acoustic performance of five commonly used reinforcing fibers was tested,and a quantitative analysis of the effects of fibers on sound absorption,transmission,and reflection of sound waves was obtained,which provided a basis for selection of fiber reinforcement of acoustic rubber.A pressure-resistant and sound-insulating glass fiber composite material was obtained,in which the low-frequency reflection coefficient can reach 0.8,and the change with pressure is also small.(4)Introduce eucommia gum blending on the basis of nitrile rubber composite material,and improve the compressive ability of the material through the high modulus of gutta percha.The mechanics of nitrile/eucommia alumina nanocomposites with different blending ratios was carried out.Acoustic testing,exploring the performance and connection between mechanics,dynamic thermodynamics,and acoustics,adding a small amount of eucommia ulmoides to blend,is conducive to improving sound absorption and compression performance,and it is determined that the best blending ratio of nitrile and eucommia is 95/15,under this blending ratio,the average ordinary pressure sound absorption performance can reach 0.7,and the compression performance is also greatly improved.The sound absorption and compression resistance are all higher than the nitrile rubber material under the filler compound,and the WLF time temperature is explored.The effect equation explores the internal relationship between the equation constants C1 and C2 and the material. |
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