Preparation And Properties Of Epoxy Viscoelastic Damping Materials

The vibration mechanical energy is converted into heat energy by the effect of internal friction of molecular chains,which is provided by polymer viscoelastic damping materials.Generally the effective damping temperature range of single polymer is narrow,and its mechanical properties and thermal stability are relatively bad.Therefore,a variety of polymers are blended in a physical or chemical way to prepare the interpenetrating polymer networks(IPN),then the composite material can be prepared by adding reinforcing filler into the IPN,which can improve these properties to some extent.In this paper,the damping properties of two kinds of cured products were compared with the curing agent polyether amine D400 and polyethylene polyamine curing epoxy resin CYD-127.Compared with polyethylene polyamine,the Tg of D400 curing products was closer to room temperature,peak of loss factor was bigger.So D400 was more suitable for curing agent for viscoelastic materials.And when D400:EP=3:10,the damping property of the cured product was the best.Then PU-EP IPNs was prepared by D400 as curing agent,and the damping properties,tensile properties,thermal stability and cross section morphology of PU-EP IPNs with different formulas were studied.Tensile test showed that 10%PU-EP IPNs had the best mechanical properties,it had the largest tensile strength and the smallest elongation at break.The DMA results showed 10%PU-EP IPNs had the best compatibility,compared with 0%PU-EP IPNs,the effective damping temperature range changed little,and the loss factor peak value increased a lot.30%PU-EP IPNs and 50%PU-EP IPNs appeared micro phase separation.30%PU-EP IPNs had widest effective damping temperature range which was 113.3?,it increased by 144% compared with 0%PU-EP IPNs,while the loss factor peak also inevitably fell a lot.Thermogravimetric analysis showed that,among the three kinds of materials of 0%PU-EP IPNs,10%PU-EP IPNs and 30%PU-EP IPNs,10%PU-EP IPNs had the best thermal stability,while 30%PU-EP IPNs had the worst thermal stability.In order to further improve the damping capacity of the material,using 30%PU-EP IPNs as the matrix material,T-ZnOw/IPN composites were prepared by adding tetrapod-shaped ZnO whisker(T-ZnOw)as enhanced filler.Then study the effect of silane coupling agent KH550 on the damping properties of the composite materials,and the influence of T-ZnOw content on damping properties,tensile properties,thermal stability and cross section morphology of composite materials.T-ZnOw can improve the damping capacity,tensile properties and thermal stability of IPN to a certain extent.When the T-ZnOw content was 1%(T-ZnOw:EP=1:100),composite material had best damping performance.Composite material with 2%T-ZnOw had largest tensile strength of 7.56 MPa,it increased by 76.6% compared to pure PU-EP IPNs.The more T-ZnOw content,the better the thermal stability of the composites.Whether or not after KH550 modification,the addition of T-ZnOw helped to improve the damping performance of the composites in the majority of temperature range.The non-modified T-ZnOw(1wt% EP)improved the damping performance in relatively low temperature range(-52.9?~33.8?)of the material.The modified T-ZnOw(1wt% EP)increased the damping performance in relatively high temperature range(-35.5?~70.0?)of the material.The composite material with modified T-ZnOw had better damping performance.