Poly(vinylidene fluoride)/Polymethylene-Based Block Copolymers and Terpolymers

Abstract

Dual crystalline diblock copolymers consisting of polymethylene (PM) and poly(vinylidene fluoride) (PVDF) blocks as well as triblock terpolymers with polystyrene (PS) as middle block were synthesized. For the synthesis, two/three different polymerization methods such as polyhomologation, atom transfer radical polymerization (ATRP), and iodine transfer polymerization (ITP) along with chain-end postpolymerization reactions were employed. Solid-state NMR spectroscopy revealed the characteristic peaks of all constituent blocks while gel permeation chromatography (GPC) results demonstrated the controlling/living nature of all implemented polymerization methods. The analysis of crystallization behavior based on differential scanning calorimetry (DSC) indicates the presence of different PVDF crystalline phases (α, β, and γ) n block copolymers. Further analysis with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopies revealed the coexistence of α- and β-phases in diblock copolymers and β- and γ-phases in triblock terpolymer. An initial study of self-assembly in DMF, a selective solvent for PVDF and PS, was performed by dynamic light scattering (DLS) and atomic force microscopy (AFM).