Well-defined linear diblock copolymers with a hydrophobic fluoropolymer poly(vinylidene fluoride), PVDF and a hydrophilic poly (2-Ethyl-2-Oxazoline), PEtOx block, were successfully synthesized by combination of cationic ring-opening polymerization (LCROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization techniques.
PEtOx was synthesized by LCROP of 2-ethyl-2-oxazoline (EtOx) monomer followed by two post-polymerization reactions, esterification, and nucleophilic substitution to introduce at the chain end the necessary RAFT agent, i.e., xanthate for the sequential RAFT polymerization of fluorinated monomer, i.e., VDF and afford the PEtOx-b-PVDF diblock copolymers.
The success of the synthesis of the macrotransfer agent and final diblock copolymers was confirmed by Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR) and Fourier Transform Infrared Spectroscopy (FT-IR). The number-average molecular weight (Mn) and the polydispersity index (PDI) of the copolymers, determined by Size Exclusion Chromatography (SEC), were 10.5–64 k and ≈1.2, respectively. The thermal properties, including glass transition (Tg), melting (Tm), and crystallization temperatures (Tc), were studied by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The self-assembly of the amphiphilic copolymers in water/DMF was evaluated using dynamic light scattering (DLS) and the polymorphism by X-Ray Diffraction (XRD).
The synthesized amphiphilic diblock copolymers combine both properties of PEtOx and PVDF, and thus render them a good candidate for biological and industrial applications.

PEtOx-b-PVDF Sythesis Scheme

Norah Aljeaban

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