Synthesis of high molecular weight poly(n-butyl acrylate) macromolecules via seATRP: From polymer stars to molecular bottlebrushes

Poly(n-butyl acrylate) (PBA) branched polymers have interesting properties and potential applications as super soft materials and pressure sensitive adhesives. Herein, star and comb polymers with long PBA sidechains were synthesized by a simplified electrochemically-mediated ATRP (seATRP) utilizing ca. 100 ppm of Cu catalyst. Grafting-from (or core-first) synthesis of PBA stars using a multifunctional sucrose initiator (Sucrose-Br-8) was best controlled using moderately negative applied potentials. This method was also applied to the synthesis of molecular bottlebrushes with long sidechains to a relatively high conversion. The prepared molecular bottlebrushes had low dispersity, with length distributions of 1.01 for the shorter bottlebrushes (backbone DP = 316) and 1.03 for the longer brushes (backbone DP = 1,632), as determined by atomic force microscopy (AFM) imaging.