Preparation And Properties Of Polyborosilicate Viscous Damping Materials

The viscous damper is an energy-dissipating element with excellent damping performance.However,the damping medium silicone oil currently used has a lot of problems such as poor visosity-temperature performaace,and the performance is greatly affected by temperature.In this article were used boric acid(H2BO3)and hydroxyl terminated polydimethylsiloxane(PDMS-OH)as raw materials to prepare polyborasiloxane(PBDMS)with different formulations by changing the hydroxyl content of PDMS-OH and the ratio of H3BO3 to PDMS-OH.Then,PDMS-OH was used to dissolve polyborosilicate,and lipophilic silica was added to adjust the viscosity of the sample to obtain polyborosilicate alkyl damping material.The effects of the hydroxyl content boron content,and silica content of PDMS-OH on the rheological properties and damping performance of polyborosiloxane-based damping materials were inexplored.The conclusions are as follows:(1)The Fourier transform infrared transform test and DSC test of polyborosiloxane found that polyborosiloxane has obvious crystallization peaks and melting peaks.Within the service temperature range of bridge dampers,polyborosiloxane is in the viscous flow stat,the performance of the material is stable.Hoowever,with the of the silicon-boron ratio of Polyborosiloxane,the absorption peak intensity of B:O bond increases gradually,and the content of B:O bond increases.(2)As the silicon-boron ratio of polyborsiloxane decreases,the viscosity,storagemodulus,and loss modulus of polyborosiloxane-based dampingmaterials decrease.With the increase of silica content,the viscosity,storage modulus and loss modulus of polyborosiloxane-based damping materials gradually increase,and the viscosity ratio between-40℃ and 25℃ also decreases gradually.When the silica content is 5.00%,its viscosity ratio is 1.89 times,which is 7.45 times better than that of WACKER silicone oil,the ratio material currently used.(3)The dynamic test of the damper on the polyborosiloxane-based damping material filled with silica shows that as the silica content increases,the force when the viscous damper starts to move gradually increases.Simultaneously analyze the speed correlation data,and as the silicon dioxide content increases,the speed index α It gradually decreases between 0.57 and 0.39,but all comply with the commonly used range in engineering,while the Wacker silicone based viscous damper cannot perform constitutive fitting.The frequency correlation of polyborosilicate alkyl damping materials weakens with the increase of silicon dioxide content,and the maximum change in damping force is 6.52%,which is less than 8.16%of Wacker silicone oil.However,the temperature-dependent test results for polyborosiloxane-based damping materials found that with the increase of silica content,the attenuation of the damping force with temperature changes decreases.When the speed is less than 78.5 mm/s,the filling The damping force of the 0.5-C1-5%viscous damper is basically unchanged.When the speed is greater than 78.5 mm/s,the damping force of the viscous damper filled with Wacker silicone oil is basically unchanged.After the 20-cycle test,the damping force attenuation of the viscous damper filled with the two damping materials is very small,and the performance of the damper is stable.