Controlled Self-Assembly of PPE-PDMS Block Copolymers: From Synthesis to Morphological Analysis
ORAL
Abstract
Block copolymers (BCPs) composed of siloxane and hydrocarbon segments readily form microphase-separated structures due to strong repulsion. In addition, siloxanes enable BCP synthesis via polymer reaction using easily introduced hydrosilyl end-groups. By leveraging these characteristics of siloxanes, we precisely synthesized poly(phenylene ether) (PPE)-poly(dimethylsiloxane) (PDMS) BCPs and achieved various morphologies, such as spheres, cylinders, and lamellae in the BCPs.
PPE was synthesized via oxidative coupling polymerization, purified by Soxhlet, and allyl-functionalized. PDMS was synthesized via ring-opening polymerization and hydrosilyl-functionalized. PPE-PDMS BCPs were synthesized via hydrosilylation, a reaction between the allyl group on the PPE chain-end and the hydrosilyl group on the PDMS chain-end. PPE-PDMS BCPs were successfully obtained without any residual homopolymers, and the volume fraction of PPE was controlled to be 0.47-0.67.
Small-angle X-ray scattering (SAXS) and transmission electron microscope (TEM) revealed the development of microphase-separated structures, including cylinders, lamellae, and spheres. Temperature-modulated SAXS showed solvent-dependent structures, where samples prepared from chloroform and dichloromethane exhibited different morphologies depending on the solvent affinity. This work demonstrates precise PPE-PDMS BCP synthesis and controlled self-assembly, opening new avenues for advanced hybrid materials.
PPE was synthesized via oxidative coupling polymerization, purified by Soxhlet, and allyl-functionalized. PDMS was synthesized via ring-opening polymerization and hydrosilyl-functionalized. PPE-PDMS BCPs were synthesized via hydrosilylation, a reaction between the allyl group on the PPE chain-end and the hydrosilyl group on the PDMS chain-end. PPE-PDMS BCPs were successfully obtained without any residual homopolymers, and the volume fraction of PPE was controlled to be 0.47-0.67.
Small-angle X-ray scattering (SAXS) and transmission electron microscope (TEM) revealed the development of microphase-separated structures, including cylinders, lamellae, and spheres. Temperature-modulated SAXS showed solvent-dependent structures, where samples prepared from chloroform and dichloromethane exhibited different morphologies depending on the solvent affinity. This work demonstrates precise PPE-PDMS BCP synthesis and controlled self-assembly, opening new avenues for advanced hybrid materials.
*This study was financially supported by JSPS KAKENHI (grant numbers 20H02785 and 24H00052), JST SPRING (grant number JPMJSP2106), and JST-CREST (JPMJCR2546). We sincerely appreciate Prof. Tomoyasu Hirai (Osaka Institute of Technology) and Dr. Noboru Ohta (JASRI) for their support in the SAXS measurements at Spring-8 BL40B2, Mr. Ryohei Kikuchi and Dr. Takashi Kajitani (Institute of Science Tokyo) for TEM and temperature-modulated SAXS measurements.
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Publication: Synthesis and Morphological Analysis of Well-Defined Poly(2,6-dimethyl-1,4-phenylene ether)‑b‑Poly(dimethylsiloxane)
Riku Takahashi, Kan Hatakeyama-Sato, Yuta Nabae, and Teruaki Hayakawa
Macromolecules 2025, 58, 5271-5282.
Presenters
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Riku Takahashi
- Institute of Science Tokyo