Study On Preparation And Performance Of The Damping Silicone Rubber For Efficient Micro-Vibration Reduction

During the operation of the satellite in orbit,,a series of micro vibration with small amplitude and wide frequency spectrum will be produced by various attitude control devices,such as the control moment gyroscope.This kind of micro vibration will seriously reduce the imaging quality of the optical load on the high-resolution satellite.Using rubber damper is a good way to reduce the micro vibration influence on optical load.Silicon rubber vibration damper has been widely used in the field of aerospace because of its light weight,high reliability,good high and low temperature resistance and radiation resistance.However,the traditional silicone rubber has low loss factor and large modulus change,which is difficult to meet the needs of vibration reduction in small magnitude and small displacement environment.In this paper,from the perspective of silicone rubber system regulation,a series of researches have been carried out around silicone rubber phenyl content,vulcanization system,reinforcement system,damping additive,etc.This paper focuses on the the relationship between the dynamic mechanical properties under small amplitude?30?m?and the structure and composition of silicone rubber.The purpose of this paper is to prepare a kind of damping silicone rubber material which can meet the vibration reduction requirements of space micro vibration environment.The following is the main research content and conclusion of this paper?1?The damping silicone rubber with different phenyl content was prepared by using methyl phenyl silicone rubber with phenyl side group as the base rubber.The effect of phenyl content on the physical and mechanical properties and dynamic mechanical properties of silicone rubber was studied.The results showed that with the increase of phenyl content,the glass transition temperature and loss factor of silicone rubber increased,but the change range of modulus increased too.In the range of-30?70?,the loss factor of low phenyl contents silicone rubber Ph-5%is only about 0.2,while the loss factor of silicone rubber Ph-20%with20%phenyl content is 0.20?0.27.And the maximum loss factor is 23%higher than that of Ph-5%.Moreover the loss factor of high phenyl silicone rubber with 30%phenyl content is further increased,tan?_maxis 0.36.?2?Two kinds of vulcanizers,2,4-dichlorobenzoyl peroxide?DCBP?and diisopropyl peroxide?DCP?,were used to vulcanize silicone rubber.The effect of two curing agents on the physical and dynamic mechanical properties of silicone rubber was studied.The results show that the loss factor of DCBP vulcanized silicone rubber was higher than DCP vulcanized silicone rubber and the change of modulus was smaller.The loss factor of DCBP vulcanized silicone rubber was 0.22-0.26 and the change of elastic modulus is 13.5MPa in the range of-30-70?.Compared with DCP vulcanized silicone rubber,the loss factor increased by 23%,while the change of modulus is reduced by 48%.?3?The effect of silica content on the physical and dynamic mechanical properties of damping silicone rubber was studied,and carbon nanotubes?CNTs?were added to silicone rubber as damping filler.The results showed that with the increase of silica content,the loss factor of silicone rubber increased,and the change of modulus also increased significantly.When silica content increased from 20 per to 60 per,the modulus of silicone rubber increased from 1.4MPa to 42.7MPa in the range of-30?70?.CNTs can improve the loss factor of silicone rubber without significantly changing the mechanical strength and modulus.The loss factor of silicone rubber with CNTs increased by 20%in the range of-70?20?,while the elastic modulus of silicone rubber at-30?only changed from 20MPa to 24MPa?4?Phenyl silicon intermediate was added to silicone rubber as damping additive and co-vulcanized with silicone rubber by DCBP.The results show that with the increase of the amount of phenyl silicon intermediate,the vulcanization degree of silicone rubber decreased,and the elongation at break,tear strength and loss factor at high temperature increased significantly.Phenyl silicon intermediate make further improvement on the hysteresis loss of silicone rubber as a new relaxation unit.After adding phenyl silicon intermediate,a damping peak appears at-30?70?,and the maximum loss factor of silicone rubber increases from 0.2to 0.3.?5?Based on the above research,the silicon rubber shock absorber was prepared.The vibration reduction effect of the new silicone rubber was verified by the finite element simulation and vibration experiments.The results show that the damping silicon rubber has a good effect on the vibration disturbance of small scale.Under the micro vibration disturbance of 100mg,the vibration response at sensitive frequency point 200Hz and 300Hz decreased by20%and 60%respectively.The modulus of the prepared silicone rubber material is stable in a wide temperature range,and the frequency deviation is no more than 10Hz in the temperature range of-30?70?.The pointing precision change of the shock absorber is less than 1?after vibration.The mass loss of silicone rubber in vacuum is 0.2%,and the condensable volatile is0.02%.After 500 krad irradiation,the mechanical properties of silicone rubber did not change significantly,and the loss factor only changed 3%.The results show that the silicone rubber material can satisfy the requirements of application in space environment.