Hierarchical ordering and multilayer structure of poly(ε-caprolactone) end-functionalized by a liquid crystalline unit: role of polymer crystallization

End functionalization is an effective avenue to develop polymers with specific functions. Microphase separation between the polymer segment and the end group can lead to end-functionalized polymers organizing into ordered structures; this behavior is more significant for crystallizable end-functionalized polymers. However, the role of polymer crystallization in the ordering organization of end-functionalized polymers remains unclear. Herein, we synthesized end-functionalized poly(ε-caprolactone) (PCL) with the liquid crystalline (LC) 4-hexyloxy-4′-cyanobiphenyl terminal, denoted LC-PCL. We demonstrated that the structural organization of LC-PCL was governed by the polymer composition and PCL crystallization. LC-PCL with a short PCL block organized in a smectic-like bilayer structure. LC-PCL with a medium PCL block length assembled in multilayers comprised of alternating PCL lamellae and LC layer; however, the formation of the LC layer was prohibited when the crystallization of PCL was fast. LC-PCL with a long PCL block only formed PCL lamellae, similar to conventional semicrystalline polymers. This study provides deep insight into the hierarchical structural organization of semicrystalline end-functionalized polymers.