Synthesis by RAFT polymerization and properties of anionic cylindrical molecular brushes bearing poly(acrylic acid) side chains

Synthesis and characterization of anionic pentablock brush copolymers bearing poly(acrylic acid) side chains on the brush blocks separated by linear poly(butyl methacrylate) blocks

“…Thus, the copolymer APBC-4 possesses weaker acidic properties compared to the similar copolymer with shorter pAA side chains APBC-1. Relatively strong acidic properties of APBC-1 comparable with those of linear pAA (pKa 5.07 ± 0.14 in 0.1 M NaCl [10]) indicate that local concentration of the ionized monomeric units and their counterions is not high in this case which could be predetermined both by low DP of pAA and the presence of linear pBMA inserts.…”

“…This copolymer was esterified with 2-bromopropionyl bromide (BPB) in the same way as described in our previous publication [10]. Modification of the pentablock copolymer resulted in its derivative containing labile bromine atoms in almost every unit of pHEMA blocks.…”

“…Synthesis of CTA containing butylthiocarbonothioylthio moieties can be done by several methods. Using one-pot method (method A, see Section 2), sodium trithiocarbonate is prepared in the mixture which is directly used for succeeding nucleophilic substitution reaction [10]. According to another method (method B, see Section 2) [48,49], a nucleophil is prepared separately and, after purification, added to the reaction mixture.…”

“…Several types of cylindrical molecular brushes bearing negatively charged side chains were synthesized and studied so far [9][10][11][12]. Anionic brush polymers constituted mainly of hydrophobic poly(meth)acrylate backbone and poly(acrylic acid) or poly(methacrylic acid) side chains, possess several attractive properties the main being pH induced changes in dimensions and low tendency to aggregation.…”

“…alkyne-azide ''click chemistry' '[9], or the synthesis of multiblock copolymers succeeded by modification of particular blocks attaching anionic side chains [10][11][12]. The first approach is rather complicated, since the reactions involving terminal functionalities of the brush molecules have steric limitations because of dense side chains.…”