Molecular Simulation And Experiment Of Resin Doped Nitrile-butadiene Rubber Ternary Hybrid Damping Material

Rubber damping materials are widely used in automotive,construction,aerospace and other fields because of their excellent damping properties.Adding small organic molecules to polar rubber matrix can form reversible hydrogen bond（H-bond）between small organic molecules and matrix,which can significantly improve the damping factor.In recent years,the preparation of high-performance damping materials has become a research hotspot.In this paper,molecular dynamics（MD）simulation and experiment were used to study the ternary hybrid damping materials of hindered phenol/nitrile-butadiene rubber/phenolic resin and hindered amine/nitrile-butadiene rubber/phenolic resin,and the anti migration antioxidant GO-4010NA was prepared and added to nitrile-butadiene rubber（NBR）to prepare NBR composites.The mechanism of improving the damping performance of NBR composites was studied from the molecular level.Combined with the experimental characterization,the quantitative relationship between H-bond and damping performance was studied to verify the accuracy of the simulation.The research contents mainly include:（1）In Chapter 3,MD simulation,experiment and linear regression analysis were used to study the ternary hybrid composites with different contents of hindered phenol AO-80/nitrile-butadiene/phenolic resin（AO-80/NBR/PR）,and the relationship between microstructure and damping properties was established quantitatively.The solubility parameters of AO-80,PR and NBR are calculated by MD simulation method.The simulation results show that AO-80,PR and NBR have good compatibility.The radial distribution function and H-bond statistics show that there are five types of H-bonds in the composite system.With the increase of AO-80 content,the free volume fraction（FFV）of the system decreases gradually,the binding energy(E_binding)increases gradually,and the number of H-bonds(N_HBs)increases gradually,which means that the interaction between AO-80 and NBR/PR matrix increases gradually.When the content of AO-80 increases to 44 phr,the FFV is the smallest,the E_binding is the largest and the number of H-bond is the largest.The H-bond is characterized by infrared from the macro level,and the damping parameters,including the peak loss factor tanδ,are obtained by dynamic mechanical property analysis tanδ_max and loss peak area TA（tanδ>0.3）,the results show that the damping performance is the best when the content of AO-80 is 44 phr.Finally,the quantitative relationship between the microstructure parameters(N_HBS,E_binding and FFV)and the macroscopic damping properties(tanδ_max and TA)was obtained by linear regression analysis.（2）In Chapter 4,small molecules of hindered amine GW-622 or GW-944 were introduced into nitrile-butadiene rubber/phenolic resin matrix（NBR/PR,abbreviated as NBPR）to prepare hindered amine/nitrile-butadiene rubber/phenolic resin ternary hybrid damping materials with high temperature damping properties.Fourier transform infrared spectroscopy（FTIR）,scanning electron microscopy（SEM）,differential scanning calorimetry（DSC）and dynamic mechanical property test（DMA）were used to characterize the microstructure,compatibility and damping properties of hindered amine/NBPR materials,respectively.FTIR results showed that a H-bond network was formed between hindered amine and NBPR matrix;DSC and SEM results show that hindered amine and NBPR matrix are partially compatible;DMA results show that the hindered amine/NBPR composite has two loss peaks,and the composite shows good damping performance in the high temperature region.With the increase of hindered amine small molecules,the high temperature damping performance of the composite is better.This study provides theoretical support for the preparation of damping materials in the high temperature region.（3）In Chapter 5,antioxidant 4010NA was grafted onto graphene oxide（GO）to prepare anti migration antioxidant（GO-4010NA）.The effects of different fillers（4010NA,GO,4010NA/GO,GO-4010NA）on the compatibility and damping properties of NBR composites were studied by MD simulation.MD simulation results show that 4010NA and GO-4010NA have good compatibility with NBR.GO-4010NA/NBR composite has the smallest FFV,the largest E_binding and strong interaction.DSC results showed that the T_g of GO-4010NA/NBR composites increased due to the formation of H-bonds in the system.DMA data show that GO-4010NA can improve the damping performance of NBR than 4010NA.Grafting 4010NA onto GO not only inhibited the migration of 4010NA,but also improved the damping properties of NBR matrix.