Synthesis and Morphological Analysis of Well-Defined Poly(2,6-dimethyl-1,4-phenylene ether)-<i>b</i>-Poly(dimethylsiloxane)

Microphase-separated structures of block copolymers have been leveraged in advanced functional materials. However, such unique morphologies have not been extensively studied for block copolymers comprising poly(2,6-dimethyl-1,4-phenylene ether) (PPE), although PPE is a commonly utilized engineering plastic. Herein, based on precisely prepared PPE, we have developed PPE-containing block copolymers, exhibiting various microphase-separated structures such as spheres, lamellae, and cylinders. As the second block component, poly(dimethylsiloxane) (PDMS) was synthesized via living ring-opening polymerization. Block copolymers (PPE-b-PDMS) with different compositions were efficiently obtained by employing hydrosilylation using Karstedt’s catalyst. Additionally, it was found that PPE-b-PDMS followed different pathways of microphase-separated structure formation depending on the solvent used for sample preparation. The developed morphologies are expected to enhance the properties of PPE through the combination with other block components and the control of nanometer-scale internal structures.