Supramolecular thermoplastic elastomers via self-complementary quadruple hydrogen bonding between polybutadiene-based triblock copolymers

Two series of triblock copolymers, polycaprolactone- b -polybutadiene- b -polycaprolactone (PCL- b -PB- b -PCL, CBC) and polylactide- b -polybutadiene- b -polylactide (PLA- b -PB- b -PLA, LBL), have been synthesized through the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL)/ D,L -lactide ( D,L -LA) catalyzed by Sn(Oct) 2 with hydroxyl-terminated polybutadiene (HTPB) as a macroinitiator. Then, these triblock copolymers are end-functionalized with 2-ureido-4[1H]-pyrimidinone (UPy) groups to obtain the supramolecular multiblock copolymers UCBC and ULBL as supramolecular thermoplastic elastomers (TPEs). The thermal properties of UCBC and ULBL samples are measured by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The tensile tests of all the samples prepared are carried out to investigate the influence of the content of hard segments and the microstructure of PB soft segments on the mechanical properties of supramolecular TPEs.