LAUSR

The synthesis of polyoxetane (POx) and amphiphilic block copolymers composed of poly(ethylene oxide) (PEO) and polyoxetane was achieved by anionic ring-opening polymerization and monomer activation. First the anionic polymerization of oxetane was conducted using an initiating system based on tetraoctylammonium bromide associated with a simple trialkylaluminum, NOct4Br/i-Bu3Al (1/>1). This methodology allowed the controlled synthesis of polyoxetanes with molar masses up to 10 000 g mol−1 and a narrow molar mass distribution (Đ < 1.2). The synthesis of diblock copolymers was achieved starting from a mixture of ethylene oxide and oxetane, thanks to their difference in reactivity. The micellization of PEO-b-POx in water was studied as a function of temperature with a shrinking phenomenon appearing at around 33 °C. Finally, a two-step procedure is also discussed for the synthesis of polyoxetane-b-poly(ethylene oxide)-b-polyoxetane triblock copolymer.