Self-assembly of poly(vinylidene fluoride)-block-poly(2-(dimethylamino) ethylmethacrylate) block copolymers prepared by CuAAC click coupling

Poly(vinylidene fluoride) (PVDF) is a very important fluoropolymer which possesses remarkable physicochemical properties such as high thermal and chemical resistances as well as ferroelectricity, for example. To date, only iodine transfer polymerization and RAFT polymerization have enabled the preparation of well-defined PVDF and of some PVDF-based block copolymers (BCPs). However, these reversible deactivation radical polymerization techniques suffer from undesired reactions which impair the synthesis of a wide range of PVDF-containing BCPs. Here, unprecedented poly(vinylidene fluoride)-block-poly(2-(dimethylamino) ethylmethacrylate) (PVDF-b-PDMAEMA) BCPs were prepared by CuAAC click coupling of azide-functionalized PVDF synthesized by RAFT polymerization and alkyne-functionalized PDMAEMA synthesized by ATRP. This strategy was quite efficient and afforded three relatively well-defined BCPs (PVDF40-b-PDMAEMA(23), PVDF40-b-PDMAEMA(69), PVDF40-b-PDMAEMA(162), D < 1.55). These amphiphilic BCPs were self-assembled in water at pH 2, 8 (native pH) and 10. The morphologies obtained were mainly polydisperse (20-500 nm), roughly spherical aggregates. However, at pH 8, PVDF40-b-PDMAEMA69 also formed micrometer-long rigid cylindrical micelles. These morphologies are likely the first examples of PVDF-containing BCP nanostructures produced by crystallization-driven self-assembly.