Modified high cis conjugated diene copolymer and manufacturing method of the same

A modified conjugated diene polymer, manufactured by a method comprising forming a conjugated diene polymer by a polymerization step and enabling the conjugated diene polymer to react with a first modifier and then react with a second modifier to obtain the modified conjugated diene polymer, wherein

• the modified conjugated diene polymer has a cis-1,4-structure and the cis-1,4-structure is higher than 97%,
• the polydispersity index (PDI) of the modified conjugated diene polymer is greater than 1.8 and less than 2.5,
• the first modifier has a chemical formula of X—R1-Si(R2)3, wherein X is a functional group selected from the group consisting of an epoxypropoxy group, an isocyanate group, and a 2-(3,4-epoxycyclohexyl group), R1 is an alkyl group with 2˜3 carbon atoms, R2 is an alkyl group with 2˜3 carbon atoms or an alkoxy group with 1˜3 carbon atoms;
• the second modifier has a chemical formula of R3-Si(R4)3, wherein R3 is selected from the group consisting of an alkyl group, an alkoxy group, an aromatic group, an aryloxy group and a cycloalkyl group with 1˜12 carbon atoms, R4 is selected from the group consisting of an alkyl group, an alkoxy group, an aryloxy group and a cycloalkyl group with 1˜12 carbon atoms.