Anionic Grafting to Strategies for Functional Polymethacrylates: Convenient Preparation of Stimuli‐Responsive Block Copolymer Architectures

Abstract

AbstractFunctional block copolymers (BCP) are promising candidates for many important applications in fields of separations technologies, drug delivery, or (nano)lithography. Here, a universal strategy is described for the preparation of functional poly(methacrylate)s grafted (PMA) to polystyrene‐block‐polyisoprene (PS‐b‐PI) BCPs via a convenient postmodification strategy. PS‐b‐PIs are functionalized by means of hydrosilylation protocols for the introduction of chlorosilane moieties. Subsequent anionic grafting‐to polymerization of different functional PMA macro anions leads to grafted BCP. Various functional and non‐functional homopolymers, that is, poly(di(ethylene glycol) methyl ether methacrylate), poly(methacrylic acid), and poly(3‐methacryloxypropyl)heptaisobutyl‐T8‐silsesquioxane as well as poly(methyl methacrylate), poly(n‐butyl methacrylate), poly(iso‐propyl methacrylate), poly(tert‐butyl methacrylate), and poly(2‐hydroxy ethyl methacrylate) are block‐selectively incorporated into the PI segment. Applied grafting strategies for the non‐functional PMA derivatives, which feature different sizes of the alkyl substituent, reveal a strong influence on the grafting‐to efficiency. The grafted BCP architectures are capable of undergoing microphase separation in the bulk state, while the resulting morphology is significantly influenced by the introduction of PMA segments as shown by transmission electron microscopy measurements. Additionally, the structure formation and pH‐switching capability of the poly(methacrylic acid)‐grafted BCP is studied by dynamic light scattering, proving the feasibility for the herein investigated synthesis strategy.