Preparation And Application Of Novel Thermoreversible Healing Of EPDM Damping Materials

High damping rubbers are widely used in vehicles,buildings,aircrafts and ships because of their high entropy-elasticity.Most neat rubbers exhibit low tensile strength and insufficient fracture toughness,which severely hampers their practical applications.Various fillers have been incorporated to improve the strength and toughness of rubbers.However,rubber compounding causes significant constraints in terms of filler dispersion or aggregation and interfacial regulation,resulting in deteriorated stretchability and interfacial regulation.In this work,modification has been carried out to EPDM rubber matrix with multinetwork structure of various combinations of hydrogen bonds and metal-based units to obtain high damping EPDM rubber.Novel modified EPDM prepared by blending of white carbon black and terpene resin have been investigated.Furthermore,a new Solid-Lock^?anti-looseness device with a structure of constrained layer damping has been prepared by using the modified EPDM.The new Solid-Lock^?anti-looseness device has good performance via transverse vibration tests which provides the solution for the loose problem.First,this paper presents a report of the synthesis of maleic anhydride,3-amino-1,2,4-triazole（ATA）,and zinc chloride（ZnCl₂）.The formation of hydrogen bonds and Zn-based units was confirmed by FTIR and SAXS.And the influence of mole ratio of ATA/MAH on tensile strength and fracture energy of EPDM were investigated.The results showed that the hydrogen bonds break first,followed by rupture of the Zn-based bonds,which dissipates energy and confers significantly improved tensile modulus and fracture toughness.Especially when the mole ratio of ATA/MAH is 1,EPDM have the highest tensile fracture energy.Furthermore,the new multinetwork structure of EPDM with various combinations of hydrogen bonds and metal-based units have been synthesized by incorporated the vulcanization system of sulphur.The results show that the dynamic nature of the sacrificial hydrogen bonding and Zn-based bonds improved the tensile strength of rubber.When the mole ratio of ZnCl₂/ATA is 0.1⁰.2,the tensile strength of the unfilled EPDM is up to 15 MPa.Meanwhile,the healing process could be performed at the same position for many times during stretching and reform with the aid of heat up unloading.Moreover,the addition of terpene resin further improved the damping property of the EPDM at high temperature range.When filled with 32 phr terpene resin,the elongation of EPDM at break is 1000%,and the EPDM have good damping property under 30℃.Finally,a new locking device has been prepared successfully by using the EPDM blended with 32 phr terpene resin applied in Solid-Lock^?locking device.Through transverse vibration test,the new type of locking device is suitable for strong vibration of complex dynamic load condition,and has good lock locking function.