Polymerization behavior and phase separated structure formed in controlled radical polymerization solution

Motokawa, Ryuhei   ; Koizumi, Satoshi; Zhao, Y.; Hashimoto, Takeji; Iida, You*

Focusing USANS plays an important role to investigate the time-evolution of hierarchically ordered structures in the controlled radical polymerization solution, preparing poly(methyl methacrylate)-block-polystyrene (PMMA-b-PS). In the reaction process to synthesize PS block chains from the end of PMMA block chain, we found the interplay between macro and microdomain structures as follows. As the polymerization proceeds, (1) first by polymerization-induced disorder-order transition, a lamellar microdomain appears and (2) second by order-order transitions, the morphologies of microdomains change to PS cylinder and successively to PS sphere. Ultra-small-angle scattering exhibits power law scattering due to macrophase separation between PMMA-b-PS and PS homopolymer, appeared as by-product.