Study On Phase Structure And Acoustic Properties Of Eucommia Ulmoides Rubber Composites

The development of economic globalization makes the noise problem more and more serious.Marine noise caused by the navigation of ship not only interferes with underwater communication,but also seriously affects the survival of marine organisms and human health.In order to reduce the impact of marine noise on organisms and humans,underwater acoustic functional materials have developed.Rubber materials are widely used in underwater acoustic fields such as shock absorption,noise reduction and sound absorption,but rubber materials still have the problems of easy deformation and narrow adaptability of damping frequency domain.As a natural crystalline material,eucommia ulmoides gum has the characteristics of high modulus,rubber and plastic duality and room temperature damping.In order to solve the problems of easy deformation and narrow damping frequency domain of rubber material,this paper prepared underwater acoustic material with excellent acoustic performance and pressure resistance by combining eucommia ulmoides gum with traditional rubber material.The contents of this research are as follows:(1)Eucommia ulmoides gum was mixed with polar chloroprene rubber to study the effects of the blending ratio on the physical and mechanical properties,damping properties,phase structure and acoustic properties of the blend.When the combined amount of eucommia ulmoides gum is less than 30 phr,eucommia ulmoides gum is dispersed in chloroprene rubber in the form of crystalline particles,which improves the mechanical properties and sound absorption property of the blend,reduces the damping property,decreases the sound transmission property first and then increases.When the amount of eucommia ulmoides gum was further increased,the structure of the two phases gradually began to change,and the sound transmission performance of the blend improved,while the sound absorption performance decreased.The results showed that the phase structure of eucommia ulmoides gum and chloroprene rubber is a key factor affecting the acoustic properties of blends.On this basis,the dispersion state of eucommia ulmoides gum in chloroprene rubber was regulated by adjusting the crosslinking density of the blend to regulate the dispersion state of eucommia ulmoides gum in chloroprene rubber.The change of crosslinking density made eucommia ulmoides gum dispersed well in chloroprene rubber,and the sound absorption performance of the blend was improved.(2)Eucommia ulmoides gum was selected to blend with nonpolar solutionpolymerized styrene butadiene rubber.When the combined amount of eucommia ulmoides gum was less than 50 phr,eucommia ulmoides gum was dispersed in the solution-polymerized styrene butadiene in the form of rubber particle,and there was no crystallization of eucommia ulmoides gum in the system.At this time,the mechanical properties and sound absorption properties of the blend decrease,and the sound transmission properties increase.After increasing the amount of eucommia ulmoides gum,the mechanical properties of the blend began to improve,the crystallization of eucommia ulmoides gum appeared in the system,and the sound absorption property of the system was still reduced.Subsequently,the effect of the crosslinking density on the acoustic properties of the blend was studied.As the crosslinking density decreased,the sound absorption property of the blend increased and the sound transmission property decreased,but there was still no crystallization in the blend.(3)Epoxidized natural rubber was introduced into the incompatible eucommia ulmoides gum and chloroprene rubber systems to improve their compatibility and regulate the dispersion of eucommia ulmoides gum in chloroprene rubber.The effects of compatibilizer on the mechanical and acoustic properties of the phase separation structure and the blend were investigated.The introduction of compatibilizer resulted in limited disruption of eucommia ulmoides gum crystallization.The sound absorption performance of the blend under normal pressure was improved,especially the sound absorption performance of the blend under pressure was improved.