Interpolymer association of amphiphilic diblock copolymers bearing pendant siloxane and phosphorylcholine groups

Abstract

ABSTRACTIn this study, amphiphilic diblock copolymers (PMPCm‐PTSMn) composed of hydrophilic poly(2‐methacryloyloxyethyl phosphorylcholine) (PMPC) and hydrophobic poly(3‐(tris(trimethylsiloxy)silyl)propyl methacrylate) (PTSM) were prepared via RAFT‐controlled radical polymerization. The subscripts m and n represent the degrees of polymerization of the PMPC and PTSM blocks, respectively. Thus, the m/n ratio represents the hydrophilic/hydrophobic balance of the block copolymer. We prepared PMPCm‐PTSMn with m/n ratios of 12, 1.8, and 0.3 and studied their association behaviors in water. PMPCm‐PTSMn with m/n ratios of 12 and 1.8 could dissolve in water. However, PMPCm‐PTSMn with an m/n ratio of 0.3 did not directly dissolve in water. First, PMPCm‐PTSMn with an m/n ratio of 0.3 dissolved in ethanol, whose solution was dialyzed in water to prepare the aqueous solution. The solubilizing state of these polymers in water was examined by light scattering, a fluorescence probe method, and TEM. These polymers took interpolymer aggregation state with various morphologies. The m/n ratios of 12, 1.8, and 0.3 yielded spherical shapes, cylindrical micelles, and vesicle interpolymer aggregate shapes, respectively. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1500–1507