Poly(ethylene glycol)-b-poly(vinyl acetate) block copolymer particles with various morphologies via RAFT/MADIX aqueous emulsion PISA

Abstract

The polymerization-induced self-assembly (PISA) of amphiphilic diblock copolymers of poly(ethylene glycol)-b-poly(vinyl acetate) in water was achieved through macromolecular design via interchange of xanthate (MADIX) polymerization in emulsion.

Synthesis of diblock copolymer spheres, worms and vesicles via RAFT aqueous emulsion polymerization of hydroxybutyl methacrylate

“…15,29,30 In particular, reversible addition-fragmentation chain transfer (RAFT) polymerization has enabled the controlled polymerization of many waterimmiscible monomers such as styrene, n-butyl acrylate, methyl methacrylate, vinyl acetate, benzyl methacrylate, glycidyl methacrylate and 2,2,2-trifluoroethyl methacrylate. [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] In principle, such RAFT aqueous emulsion polymerization formulations provide a convenient surfactant-free route for the synthesis of sterically-stabilized nanoparticles with various morphologies. 11,48,49 In practice, there are many literature examples of such syntheses that are restricted to kineticallytrapped spheres.…”

“…63 Vinyl acetate is another example of a monomer with moderate aqueous solubility (26 g dm −3 at 50°C) that allows access to higher-order mor-phologies during PISA syntheses. 47 More specifically, Galanopoulo and co-workers reported the formation of spheres, vesicles or large compound vesicles when chainextending a water-soluble PEG precursor with vinyl acetate via RAFT aqueous emulsion polymerization. 47 In 2014 Ratcliffe et al briefly examined the RAFT aqueous emulsion homopolymerization of HBMA as part of a broader copolymerization study.…”

“…47 More specifically, Galanopoulo and co-workers reported the formation of spheres, vesicles or large compound vesicles when chainextending a water-soluble PEG precursor with vinyl acetate via RAFT aqueous emulsion polymerization. 47 In 2014 Ratcliffe et al briefly examined the RAFT aqueous emulsion homopolymerization of HBMA as part of a broader copolymerization study. 68 More specifically, a carboxylic acid functionalized PGMA 60 precursor was chain-extended with HBMA at 70°C to prepare a series of kinetically-trapped PGMA 60 -PHBMA x diblock copolymer spheres (x = 75-500) at around pH 5-6.…”

Surfactant-free emulsion polymerization of vinylidene fluoride mediated by RAFT/MADIX reactive poly(ethylene glycol) polymer chains

“…31,[33][34][35] Hence, water-soluble chains obtained either by the RAFT polymerization of hydrophilic monomers or via the chemical modification of preformed polymers can act as chain transfer agent (and referred to as macroCTA) generating stabilizers during an emulsion polymerization by forming amphiphilic block copolymers in situ. PEG-based macroCTA have thus been reported for the PISA synthesis of various kinds of particles, [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] but to the best of our knowledge, never for PVDF latexes. Using very low amounts of such macroCTA in an emulsion polymerization seems to be an economically viable approach to access surfactant-free latexes.…”

Poly(vinyl acetate-co-ethylene) particles prepared by surfactant-free emulsion polymerization in the presence of a hydrophilic RAFT/MADIX macromolecular chain transfer agent

“…We successfully undertook several studies based on this concept employing hydrophilic polymer chains obtained by reversible addition-fragmentation chain transfer (RAFT) and macromolecular design by interchange of xanthates (MADIX) in order to produce industrially relevant surfactant-free formulation for the production of film forming latex such as poly (meth)acrylics, [38][39][40][41] poly(vinylidene fluoride) 42 and poly(vinylidene chloride). [43][44][45] In the present paper, we apply this strategy for the first time to the emulsion copolymerization of ethylene and vinyl acetate for the production of VAE, building on our recent works on the polymerization of ethylene by free radical polymerization in water under mild conditions (i.e., temperature <90°C and ethylene pressure <250 bar), [46][47][48] and on PVAc 49,50 and polyethylene (PE) 51 particle synthesis mediated by macromolecular chain transfer agents (macroCTAs). The reactivity of these two monomers restricts the choice of potential macroCTAs to hydrophilic polymer chains carrying dithiocarbonate or dithiocarbamate end groups.…”