Study On The Structure And Properties Of Trans-1,4-polyisoprene

Trans-1,4-polyisoprene(TPI)material is excellent in performance,wear resistance and tear strength.Due to simple molecular structure,good regularity of segment,low internal friction and low heat generation,TPI is an ideal material for green tire preparation.In addition to its application in the tire field,TPI can also be used in plastic modification,submarine cables,airtight rubber compositions and other special environments.In addition to its application in the tire field,TPI can also be used in plastic modification,submarine cables,airtight rubber compositions and other special environments.In this paper,from the microscopic and macroscopic levels,the experimental and simulation methods are combined to study the microstructure,crystal structure of trans-1,4-polyisoprene,the related properties of crystals under condensed state,the crystallization processes in complex systems,and dynamic behavioral simulation of molecular crystallization in dynamic environments are introduced.In this paper,Trans-1,4-polyisoprene with a Mooney viscosity of 153 was synthesized by the bulk polymerization method using the Ziegler-Natta catalyst,and Trans-1,4-polyisoprene with the Mooney viscosity of 30,39,52,60,61,73,84,104,127 was studied together to study the effect of relative molecular mass on mechanical properties,crystallinity,processability and tensile properties of polymerized products.The microstructure and properties of the trans-1,4-polyisoprene were investigated by infrared,NMR,WAXD,DSC and other analysis.The experimental results showed that the synthesized polymerization product was trans-1,4-polyisoprene(99.65%)and contains small cis-1,4 content(0.3%).The product contains ?-form(monoclinic),?-form(orthorhombic),the ?-form forms a black cross extinction pattern at a temperature lower than 35?,and the a-form forms dendritic spherulites at a temperature of about 45?,and the content of a-form increases with increasing temperature.Through tensile and dynamic mechanical properties tests,it was found that the tensile strength and elongation at break increased first and then decreased with the increase of Mooney viscosity,and the tensile strength reached the maximum when the Mooney viscosity was around 90.The storage modulus increases with frequency,and tan ? decreases with increasing frequency.Trans-1,4-polyisoprene with a Mooney viscosity of 153 was synthesized by bulk polymerization using a combination of experimental and simulation methods.Molecular simulations were used to study the properties of TPI including free volume fraction,crystallization,aging mechanism,and cohesive energy density.The result showed that the minimum ideal degree of polymerization required for the simulation was 20.The a-form conformation is trans-CTS-trans-CT,the p-form conformation is trans-STS,and the S is 115° and the T is 179°.The trans-1,4-polyisoprene(TPI)having a degree of polymerization of 20 had a glass transition temperature of 197 K.The angles corresponding to a-cell and ?-cell in the experimental data are basically consistent with the results obtained by the simulation.