Material Research And Structure Design Of Polyurethane Non-pneumatic Tire

The invention of rubber inflatable tires greatly promoted the development of the tire industry.While bringing economic development and convenience to people’s travel,there are also problems such as traffic accidents caused by air leaks and tire bursts,as well as the pollution of the environment by waste tires.Polyurethane non-pneumatic tire can solve the above problems to a certain extent,but the performance of non-pneumatic tire not only depends on high-performance polyurethane materials,but also on reasonable structural design.Therefore,studying polyurethane materials with excellent performance and optimizing the design of non-inflatable tire structures is of great significance for the application of polyurethane non-pneumatic tire.This work is based on molecular assembly design to prepare polyurethane elastomers with excellent dynamic mechanical properties and low-temperature elasticity.A new hollow structure non-pneumatic tire was designed,and non-inflatable tire samples were prepared by casting and related tests were carried out.The research content includes:(1)Poly(ε-caprolactone)(PCL)was used as the soft segment,and 4,4’-diphenylmethane diisocyanate(MDI-100)and 1,4-butanediol(BDO)were used as the hard segment to investigate the effects of prepolymer isocyanate index(NCO%)and soft segment molecular weight on the performance of the elastomer.The performance of the material were characterized by universal material testing machine,dynamic mechanical analyzer,thermal analyzer,differential scanning calorimeter,and rubber hardness tester.The results showed that when the prepolymer NCO% was 6.0 and the PCL mass ratio of soft segment molecular weight of 1000 and 2000 was 3:2,the synthesized polyurethane elastomer had the best comprehensive performance.This formulation of elastomer had excellent mechanical and dynamic mechanical performance.Meanwhile,a new type of hollow structure non-pneumatic tire was designed,and the prepared non-pneumatic tire samples passed the durability test for mediumspeed and low-load tires.(2)Poly(dimethylsiloxane)(PDMS)was used as the soft segment,and MDI-100 and BDO were used as the hard segment to systematically investigate the effects of prepolymer NCO% and soft segment molecular weight on the performance of the elastomer.The performance of the material were characterized by universal material testing machine,dynamic mechanical analyzer,thermal analyzer,differential scanning calorimeter,and rubber hardness tester.The results showed that when the prepolymer NCO% was 6.0 and the molecular weight of PDMS was 1000,the synthesized polyurethane elastomer had the best comprehensive performance.This elastomer exhibited excellent low-temperature elasticity,and the prepared non-pneumatic tire samples passed the durability test for medium-speed and low-load tires,showing better durability.However,the non-pneumatic tire prepared from this elastomer did not meet the relevant technical requirements for high-speed and heavy-load applications,and further optimization of the materials and structure is needed.(3)MDI-100 and BDO were used as the hard segment,and a blend of 1000 molecular weight PDMS and PCL mixed with polyol was used as the soft segment.The effects of the PDMS/PCL ratio in the blend polyol on the performance of the elastomer were systematically investigated based on a prepolymer NCO% of 6.0.The performance of the material were characterized by universal material testing machine,dynamic mechanical analyzer,thermal analyzer,differential scanning calorimeter,and rubber hardness tester.The results showed that when the molar ratio of PDMS to PCL in the blend polyol was 1:1,the elastomer had the best comprehensive performance.This elastomer exhibited excellent mechanical and lowtemperature elasticity performance and could be used for the preparation of non-pneumatic tire.Meanwhile,the finite element method was used to analyze the relevant mechanical behavior of the non-inflatable tire and modify the structure to optimize the non-pneumatic tire structure.A high-speed and heavy-load non-inflatable tire sample was prepared using a dual soft segment polyurethane elastomer and tested for durability.The results showed that the tire met the relevant technical requirements,providing theoretical and practical support for the high-speed application of polyurethane non-pneumatic tire.