Block copolymers, composed of two or more chemically different polymer blocks connected by covalent bond, can self-assemble into periodically segregated nanostructure. The phase behavior of block copolymer is dictated by the Flory-Huggins interaction parameter between dissimilar blocks (χ), volume fraction (f), and degree of polymerization (N). In this study, we investigated the segregation behavior of a molten diblock copolymer, poly(butyl acrylate)-b-poly(methyl methacrylate-r-styrene) (PBA-b-P(MMA-r-St)) where styrene is incorporated as a comonomer in the second block for controlling the incompatibility between two blocks. Poly(butyl acrylate)-b-poly(methyl methacrylate-r-styrene) (PBA-b-P(MMA-r-St)) was synthesized by atom transfer radical polymerization (ATRP). The PBA block has a relatively narrow molecular weight distribution (MWD: 1.06) and the P(MMA-r-St) block has a relatively polydisperse molecular weight distribution (MWD: 1.2 ~ 1.5). To examine the effect of styrene comonomer fraction (φ) on the segregation behaviors of PBA-b-P(MMA-r-St), the bulk morphologies of PBA-b-P(MMA-r-St) with different φ were characterized by transmission electron microscopy (TEM) and small angle x-ray scattering (SAXS). The effective χ parameter between PBA block and P(MMA-r-St) block was estimated by analyzing SAXS profiles with the random phase approximation (RPA), which allows us to quantify the degree of incompatibility of PBA-b-P(MMA-r-St) diblock copolymer as a function φ.

Effect of comonomer composition on the segregation behaviour of poly(butyl acrylate)-b-poly(methyl methacrylate-r-styrene) prepared by atom transfer radical polymerization

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.