POS1-1231
Precision Synthesis of Graft Alternating Copolymers: Sequence Impact on Self-Assembly Behaviors
Topic
S1. Polymer Synthesis
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Aoto Ishikawa (Graduate School of Engineering, Kyoto University)
Co-Author(s)
Abstract
Advances in precision polymerization have enabled the synthesis of graft copolymers, revealing self-assembly behaviors distinct from those of block copolymers. However, precise control over the sequence arrangement of graft chains remains challenging, and the influence of graft-chain sequence on self-assembly has attracted considerable interest.
In this study, we have achieved the synthesis of “graft alternating copolymers” via selective radical cyclopolymerization of a divinyl monomer, followed by post-polymerization modification reaction and grafting to/from reactions. Importantly, this synthetic strategy enables precise control over the molecular weight (MW) of both the backbone and graft chains, allowing sequence-dependent self-assembly behavior to be systematically evaluated through comparison with the corresponding graft random copolymers and conventional block copolymers having comparable molecular weights.
As an example, a graft alternating copolymer bearing periodically arranged crystalline poly(L-lactide) (PLLA) graft chains were precisely synthesized. Comparison with the corresponding graft random copolymer revealed the alternating sequence exhibited higher crystallinity. We also investigated stereocomplex crystallization. Furthermore, we successfully synthesized a graft alternating copolymer in which immiscible polystyrene (PS) and polylactide (PLA) graft chains were arranged alternately. Compared with the graft random copolymer and block copolymer, the alternating copolymer formed more well-defined microphase-separated structures with smaller domain spacings. We also investigated the effects of backbone/graft chain length as well as morphology control.
In this study, we have achieved the synthesis of “graft alternating copolymers” via selective radical cyclopolymerization of a divinyl monomer, followed by post-polymerization modification reaction and grafting to/from reactions. Importantly, this synthetic strategy enables precise control over the molecular weight (MW) of both the backbone and graft chains, allowing sequence-dependent self-assembly behavior to be systematically evaluated through comparison with the corresponding graft random copolymers and conventional block copolymers having comparable molecular weights.
As an example, a graft alternating copolymer bearing periodically arranged crystalline poly(L-lactide) (PLLA) graft chains were precisely synthesized. Comparison with the corresponding graft random copolymer revealed the alternating sequence exhibited higher crystallinity. We also investigated stereocomplex crystallization. Furthermore, we successfully synthesized a graft alternating copolymer in which immiscible polystyrene (PS) and polylactide (PLA) graft chains were arranged alternately. Compared with the graft random copolymer and block copolymer, the alternating copolymer formed more well-defined microphase-separated structures with smaller domain spacings. We also investigated the effects of backbone/graft chain length as well as morphology control.
