A high-strain shape memory polymer, cis-1,4-polybutadiene–polyethylene (CPB-PE) semicrystalline copolymer with 2-ureido-4[1H]pyrimidinone (UPy) side groups (UHPB), was synthesized by grafting UPy groups onto CPB and a subsequent partial hydrogenation reaction. In the shape memory process, the robust physical crosslinking via hydrogen bonding through UPy dimerization provided the permanent network, while the crystalline PE segments served as a switching phase to afford the temporary network. The broad melting transition ranging from 35.1 to 84.2 °C allowed this material to achieve multi-shape memory behaviors by choosing two and more switching temperatures within or above the melting transition. The shape memory performance was markedly influenced by the selected critical switching temperature; in other words, the shape fixity and recovery were dependent on the fraction of the recrystallized and remelted PE phase during shape fixing and recovery processes, respectively. The two-way shape memory effect under a constant load of this system was also attained by the crystallization-induced elongation and melting-induced contraction of the PE segments in UHPB. Moreover, UHPB exhibited an excellent recoverable high-strain capacity; the shape recovery reached 96.2% at a high strain of 480%.

trans-1,4-Selective coordination chain transfer polymerization of 1,3-butadiene was achieved by using a Nd(Oi-Pr)₃/Mg(n-Bu)₂ catalyst, affording polybutadienes having high trans-1,4 contents (ca. 96%), moderate molecular weight (M_n = 1.0–2.3 × 10⁴), and narrow polydispersity (M_w/M_n ∼ 1.7). In the system, Mg(n-Bu)₂ acted as both a co-catalyst and a chain transfer agent, and the calculated transfer efficiencies of Mg(n-Bu)₂ were 27–34%. The produced living polybutadiene could further initiate the ring-opening polymerization of ε-CL/lactide to give TPB-b-PCL/PLA copolymers in a controlled fashion. The crystalline amphiphilic copolymers (TPB-b-PCL/PLA) were subsequently applied to investigate their self-assembly behavior by adding a selective solvent into a polymer/co-solvent solution. The polymer plates composed of a crystallized TPB core and PCL/PLA brushes were obtained by the crystallization-driven self-assembly. Moreover, the morphology of the polymers underwent change from nano-sized plates to micro-sized plates with increasing addition of the selective solvent.