Preparation And Properties Of Polyurethane Elastomer Based On Sandwich Structure Of Anti-collision Box

The development of lightweight,high-strength polyurethane-steel composite structural plate is of great significance to the application of polyurethane elastomer.The polyurethane core material in the composite structure board has an important influence on the function of the structural plate.In this paper,a polyurethane elastomer material with high strength,good heat aging resistance and excellent processability was designed,which was suitable for the SPS composite board.The mechanical properties,process performance,heat resistance,the microphase separation structure was characterized.O n this basis,the corresponding SPS composite plate was prepared,its three-point bending performance was tested and the life of the core material was predicted.Finally,it was applied to a new type of pier crash box.First,polytetrahydrofuran polyol(PTMG)with molecular weight of 1000 was selected as the soft segment,TDI-100+ MOCA,MDI-50 + MOCA and MDI-100+ BDO were used as hard segments.Three kinds of polyurethane elastomers were prepared by prepolymer method.The lifetime,heat and mechanical properties,hydrogen bonding and microphase separation of the samples were tested by rotary viscometer,Fourier transform infrared spectroscopy,DSC,TG and so on.The results show that the process performance,mechanical properties and heat resistance of TDI-100-MOCA system is good,and suitable for the hard segment of polyurethane.Second,the soft segment structure was changed,the blends of PTMG,PPG were used as the soft segment structure of polyurethane.Five kinds of polyurethane elastomer samples with different soft segment structure were prepared by prepolymer method.It is found that mPTMG: mPPG = 70: 30 blended as soft segment polyurethane is better in processing technology,mechanical properties,heat resistance and micro phase separation,and is suitable for the soft segment structure of polyurethane.Then,TDI-100-MOCA was used as hard segment,and mPTMG: mPPG = 70: 30 blends was used as soft segment.Polyurethane elastomer sample was prepared by semi-prepolymer method,Prepolymer pre-mixing method and Prepolymer post-mixing.The effects of different synthesis technology on the structure and properties of polyurethane elastomers were investigated.The results showed that the polyurethane prepared by Prepolymer post-mixing not only has good mechanical properties but also better process performance.On the basis of the above experiment,the corresponding polyurethane elastomer and its SPS structural plate were prepared.The service life of the polyurethane core material was predicted by thermal degradation kinetics: the continuous use time at 60 ? was 6.91 × 108min(about 1315 years),and the continuous use time was 80 ? for 2.08 × 107 min About 39 years).Through the three-point bending test of the SPS structural plate,the quality of the SPS composite plate was reduced by 51.80% compared with the same bending resistance steel plate.Finally,the polyurethane is applied to the anti-collision box,and the anti-collision box was successfully installed in Jiangmen City Xiaogang Bridge 20 # piers.