Preparation And Properties Of Thermoplastic Poiyurethane Based Damping Materials

Thermoplastic polyurethane(TPU)has both the high elasticity of rubber material and the plasticizing processability of plastic material at high temperature,and its excellent mechanical properties,which has a very broad application prospect at present.However,the damping property of single TPU material is poor and the cost is high.From this point of view,this paper prepared thermoplastic polyurethane based damping material by melt blending process,in order to improve the damping property of TPU and reduce the cost.In this paper,polyvinyl chloride(PVC)and nitrile butadiene rubber(NBR)were selected to modify TPU respectively.The effects of blending proportion,packing type,acrylonitrile content of NBR and blocked phenolic small molecule AO-60on the damping property,mechanical properties and compatibility of thermoplastic polyurethane damping material were investigated.The molecular dynamics simulation and experiment were combined.The main research work of this paper is as follows:Firstly,The PVC/TPU blends were prepared.The effects of the blend ratio of PVC/TPU,the type of TPU and the type of fillers on the damping and mechanical properties of PVC/TPU blends were studied.The results show that the 60/40 PVC/TPU blends ratio has the best mechanical properties and damping properties.The damping property of aromatic TPU is better than that of aliphatic TPU and PVC.Compared with talcum powder and mica,nano calcium carbonate is more suitable for PVC/TPU blends because of its best mechanical properties and damping properties.Secondly,The NBR/TPU blends was prepared.The effects of blend ratio of NBR/TPU,filler type and acrylonitrile content of NBR on the damping property,mechanical properties and compatibility of the blend were studied.The results show that the physical properties of NBR/TPU blends decrease gradually with the increase of NBR/TPU blends,and the peak value of tan?of NBR/TPU blends increases,while the effective damping temperature domain has little change.The compatibility of talcum powder with blends is better than that of silica,and the mechanical properties and damping properties of blends are better.With the increase of acrylonitrile content from18%to 40%,the mechanical properties of NBR/TPU blends are improved,the peak value of damping loss(tan?_MAX)increases,the effective damping temperature domain moves to room temperature,and the damping properties are improved,but the effective damping temperature range is not broadened.Thirdly,In this chapter,molecular dynamics simulation and experiment were combined.The small molecule AO-60 was added into the NBR/TPU blends system,and molecular dynamics simulation software was used to construct the AO-60/NBR/TPU blends model.The experimental results show that with the increase of the amount of AO-60,the damping properties of NBR/TPU blend system are improved,the tan?_MAXincreases from 1.1 to 1.43,and the effective damping temperature range increases from34?to 51?.Kinetic calculation results show that with the increase of AO-60 content,the binding energy of the blend system increases,the free volume fraction decreases and the number of hydrogen bonds increases.The number of intermolecular hydrogen bonds in the mixed system increases,and the breaking and generation of hydrogen bonds increase the energy loss of the system,which leads to the improvement of the damping performance of the system.As the binding energy increases,the intermolecular attraction of the blend system increases,and the work of the blend in the process of being stretched increases,the macroscopic mechanical properties of the blend are improved.