A one-pot two-step efficient metal-free process for the generation of PEO-b-PCL-b-PLA amphiphilic triblock copolymers

Abstract

In an effort to reduce hazardous chemicals, a one-pot two-step process with active bases and inactive salts was developed for the synthesis of high molar mass PEO-block-PCL-block-P(L- or D,L-LA) amphiphilic triblock copolymers. A series of poly(ε-caprolactone) (PCL)/poly(L- or D,L-lactide) (P(L- or D,L-LA)) di- and triblock copolymers have been prepared in bulk from metal-free catalytic systems and starting from either 1-pyrenemethanol or poly(ethylene oxide) (PEO) macroinitiator. The controlled generation of such structures was obtained after screening and comparing a wide variety of organic activators. Narrower dispersity characterizing each sample prepared from the PEO macroinitiator were elucidated by theoretical modeling. Finally, the ability of those triblock copolymers to self-associate in water was studied by dynamic light scattering and compared to PEO-b-P(CL-co-LA) copolymers.