Preparation And Interfacial Bonding Mechanism Of Co-Cured Damping Film-Embedded Composites

Fiber reinforced resin matrix co-cured damping composites have shown great application prospect in satellite navigating equipment,carrier rockets and high-speed trains in recent years due to its large specific modulus,high specific strength and excellent damping performance.The vulcanized rubber sheets are used as damping film materials of traditional co-cured damping composites,which are bonded to the composites through adhesives.The damping material and resin matrix fail to achieve co-curing due to the preparation process does not consider the vulcanized property,aging resistance of damping film material and curing mechanism of resin matrix.Under the action of high temperature and high pressure,it is easy to lead to the weak mechanical properties and aging failure of damping film,so that the whole structure loses the bearing capacity.However,the traditional co-cured damping composites have been unable to meet the increasing demand of human beings as the mechanical properties and vibration and noise control level are increasingly required.Therefore,how to further improve the interfacial bonding strength and damping performance of co-cured damping composites has become a key issue to be solved urgently.In view of the defects of existing co-cured damping composites,the ingredients of viscoelastic damping material were designed according to the principle of polymeric reaction and orthogonal test criterion.The preparation technology of low(80℃),medium(140℃and 165℃)and high temperature(230℃)co-cured damping composites were investigated.The mechanical properties of the damping composites were characterized.The microscopic interface bonding mechanism between damping film material and resin matrix in phenolic,epoxy and bismaleimide resin matrix co-cured damping composites was systematically revealed.The main work and innovation point of this paper are as follows:(1)The process system of co-curing damping composites was improved.The preparation technology and design method of phenolic,epoxy and bismaleic resin matrix co-curing damping film-embedded composites were developed by combining the theory of polymer forming with the co-curing process of composites.The co-curing damping film-embedded composites with different temperatures and different kinds of resins had been developed.It was of great significance to the mass production and application of co-cured damping film-embedded composites.(2)The viscoelastic damping materials matching with resin matrix were designed based on polymer theory and co-curing process.The interfacial bonding problem of co-cured damping film-embedded composites was explored from the perspective of chemical molecular bonds.The interface bonding mechanism of co-cured damping composites was revealed by combining mechanical methods with chemical characterization methods.The final results confirmed that the functional groups between phenolic resin and nitrile rubber,epoxy resin and brominated butyl rubber,and bismaleimide resin and fluorine rubber were chemically cross-linked.The viscoelastic damping material was closely bonded to the composite laminates through chemical molecular bonds,which greatly improved the interfacial bonding strength of co-cured damping film-embedded composites.(3)In view of the characteristics that viscoelastic materials were not easy to vulcanize and had short service life in low and high temperature environment,vulcanized parameters of the damping film were adjusted according to the curing process of resin matrix.Semi-effective vulcanization system and peroxide vulcanization system were proposed to improve the vulcanized characteristics of viscoelastic materials.The mechanical properties and aging resistance of viscoelastic materials were enhanced by using carbon black and white carbon black and zinc methacrylate.The co-curing theory of high and low temperature co-curing damping composites was improved.The chemical bonding between resin matrix and viscoelastic material at the interface was realized.The variation of damping properties and interfacial bonding performance of co-cured damping film-embedded composites with material parameters was investigated.(4)In view of the characteristics of low loss factor and narrow effective damping temperature range of polymer materials at ambient temperature,the orthogonal test method was combined with the design principle of polymer materials,and the additive with large particle size and high surface activity was proposed as the reinforcing system of viscoelastic materials.The effects of accelerator,vulcanized aid agent and resin curing agent on the damping properties of viscoelastic materials were explored.Finally,viscoelastic damping materials with high damping loss peak and wide effective damping temperature range were developed.The free vibration attenuation test and modal test module of co-cured damping film-embedded composites were built.Co MParing the test results with traditional damping composite,the damping performance of co-cured damping film-embedded composite was greatly improved.