Well‐defined amphiphilic polymethylene‐b‐poly(acrylic acid) diblock copolymers: New synthetic strategy and their self‐assembly

Abstract

Well‐defined amphiphilic polymethylene‐b‐poly (acrylicacid) diblock copolymers have been synthesized via a new strategy combining polyhomologation and atom transfer radical polymerization (ATRP). Hydroxyl‐terminated polymethylenes (PM‐OH) with different molecular weights and narrow molecular weight distribution are obtained through the polyhomologation of dimethylsulfoxonium methylides following quantitative oxidation via trimethylamine‐N‐oxide dihydrate. Subsequently, polymethylene‐based macroinitiators (PM‐MIs Mn = 1,300 g mol−1 [Mw/Mn = 1.11] and Mn = 3,300 g mol−1 [Mw/Mn = 1.04]) are synthesized by transformation of terminal hydroxyl group of PM‐OH to α‐haloester in ∼100% conversion. ATRPs of tert‐butyl acrylate (t‐BuA) are then carried out using PM‐MIs as initiator to construct PM‐b‐P(t‐BuA) diblock copolymers with controllable molecular weight (Mn = 8,800–15,800 g mol−1 Mw/Mn = 1.04–1.09) and different weight ratio of PM/P(t‐BuA) segment (1:1.7–1:11.2). The amphiphilic PM‐b‐PAA diblock copolymers are finally prepared by hydrolysis of PM‐b‐P(t‐BuA) copolymers and their self‐assembly behavior in water is preliminarily investigated via the determination of critical micelle concentrations, dynamic light scattering, and transmission electron microscope (TEM). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Semi-crystalline polymethylene-b-poly(acrylic acid) diblock copolymers: aggregation behavior, confined crystallization and controlled growth of semicrystalline micelles from dilute DMF solution

“…32 Number-average molecular weight (M n ), polydispersity index (M w /M n ), crystallization temperature (T c ) and melting temperature (T m ) of all the samples are listed in Table 1. Details about their synthesis and structural characterization can be found elsewhere.…”

Polymethylene‐Based Copolymers by Polyhomologation or by Its Combination with Controlled/Living and Living Polymerizations

“…An amphiphilic diblock copolymer of PM‐ b ‐PAA (PAA: polyacrylic acid) was also synthesized by the same way. A PM–Br macroinitiator was employed to initiate ATRP of tert ‐butylacrylate that produced a PM‐ b ‐PAA diblock copolymer after hydrolysis of the tert ‐butyl ester group in the presence of trifluoroacetic acid (TFA) (Scheme ) . Two PM–Br macroinitiators, with molecular weight of 1300 and 3300 g mol −1 , PDI of 1.11 and 1.04, respectively, were employed for the ATRP of tert ‐butylacrylate leading to two series of narrowly dispersed PM‐ b ‐PAA copolymers (PDI less than 1.09.)…”

“…Dependence of fluorescence intensity ratios of pyrene emission bands on the concentrations of PM‐ b ‐PAA [PM‐ b ‐PAA was obtained from PM‐ b ‐P t BA ( M n, PM = 1300 g mol –1 , M n, PM‐ b ‐P t BA = 15 800 g mol –1 )]. Reproduced with permission . 2012, Wiley.…”

Well-defined polyethylene-based graft terpolymers by combining nitroxide-mediated radical polymerization, polyhomologation and azide/alkyne “click” chemistry

“…The resulting star is subsequently oxidized/hydrolyzed to afford hydroxyl-end-capped linear PEs. [30][31][32][33] The hydroxylfunctionalized PE can be used directly as initiator for (ROP) [34][35] of cyclic ethers/esters or indirectly, after chemical modification, for (ATRP), [36][37][38][39] (RAFT) 40 and ring-opening metathesis polymerization (ROMP). [41][42][43] In this work, we report the synthesis of novel polyethylene-based graft terpolymers via the "grafting onto" strategy by combining NMP, polyhomologation and CuAAC "click" chemistry.…”