Quantum Chemistry Theoretical Studies on Molecular Structures of Polybutadiene

The Density Function Theory (DFT) method are employed to study the geometries of the polybutadiene （C4H6）n（n=3，4，5）on the base of B3LYP/6-311+G in the paper. the polybutadiene have five isomers, including Cis-1，4-polybutadiene, Trans-1, 4-polybutadiene, Isotactic1, 2-polybutadiene, Syndiotactic1，2-polybutadiene, Atactic1, 2-polybutadiene. The molecular structures of each isomer were evaluated on the basis of single point energy with zero point vibration correction. The results show that the energies of polybutadiene varied with increase of molecular weight.