Synthesis and characterization of hydroxyl-terminated polybutadiene

To expand the application of Cu(I) catalyzed cycloaddition(CuAAC) between terminal alkynes and azides in the system of polybutadiene prepolymer, the target prepolymer of azido-terminated polybutadiene(ATPB) was successfully prepared through the end-group modification with hydroxyl-terminated polybutadiene(HTPB) as reaction substrate. FT-IR analysis shows that the characteristic peak of hydroxyl groups of HTPB disappears in the FT-IR spectra of ATPB, and the characteristic peak of azide groups appears at 2097 cm^-1. ¹³C-NMR analysis indicates that the characteristic peak of carbon atoms connected with hydroxyl groups of HTPB disappears in the ¹³C-NMR spectra of ATPB, and the characteristic peak of carbon atoms connected with azide groups appears at δ52.81. The end groups of HTPB are completely modified to generate ATPB. The GPC analysis reveals that the process of the end-group modification of HTPB does not affect the polymer molecular weight and its distribution. Elemental analysis indicates that the azide value of the target product ATPB is 0.67 mmol/g, which is consistent with the theoretical value.