Multidimensional Control of Repeating Unit/Sequence/Topology for One-Step Synthesis of Block Polymers from Monomer Mixtures

Abstract

Synchronously and thoroughly adjusting the chemical structure difference between two blocks of the diblock copolymer is very useful for designing materials but difficult to achieve via self-switchable alternating copolymerization. Here, we report self-switchable alternating copolymerization from a mixture of two different cyclic anhydrides, epoxides, and oxetanes, where a simple alkali metal carboxylate catalyst switches between ring-opening alternating copolymerization (ROCOP) of cyclic anhydrides/epoxides and ROCOP of cyclic anhydrides/oxetanes, resulting in the formation of a perfect block tetrapolymer. By investigating the reactivity ratio of these comonomers, a reactivity gradient was established, enabling the precise synthesis of block copolymers with synchronous adjustment of each unit’s chemical structure/sequence/topology. Consequently, a diblock tetrapolymer with two glass transition temperatures (T g) can be easily produced by adjusting the difference in chemical structures between the two blocks.

Efficient and stable organic solar cells enabled by multicomponent photoactive layer based on one-pot polymerization

“…Unlike the time-consuming post-treatment such as Soxhlet extraction, the procedures for material synthesis are evidently simplified. For the synthesis of the conjugated diblock or triblock polymers, a small amount of low M n oligmers or polymer blocks (PM6 and L15 or PY-IT blocks in our case) are indeed included except the majority of ambipolar block copolymers (PM6- b -PY-IT or PM6- b -L15 here) even in quasi-living polymerization and self-switchable alternating copolymerization for conjugated block polymers 53 , 54 . Therefore, the obtained multicomponent polymers S11 (or S9) from the one-pot synthesis method may contain some of PM6, L15 (or PY-IT), and PM6- b -L15 (or PM6- b -PY-IT) due to deactivated polymerization sites, but the block copolymers are in majority 50 , 51 .…”

Understanding differences in rate versus product determining steps to enhance sequence control in epoxide/cyclic anhydride copolymers

“…Satoh and coworkers have shown how multiblock polymers, either block-like or gradient, can be achieved through one-pot mixtures of epoxides/cyclic anhydrides/cyclic esters/cyclic carbonates using simple pivalate salts, with one epoxide and up to six anhydrides. [20][21][22] These studies identified that certain monomer pairs proceeded to polymerization preferentially before others, leading to block copolymer formation. These reports show that there is promise for sequence-controlled block polyesters via ROCOP of epoxides and cyclic anhydrides and that further investigations are warranted.…”

Alkali metal carbonate catalyzed copolymerization of anhydrides and epoxides: a simple, efficient and versatile approach to well-defined alternating polyesters

“…Very recently, alkali metal carboxylates have been demonstrated as simple and green initiators for ROAC. [33][34][35][36][37][38] However, a chainend elimination side reaction limits the achievement of endfunctional polymers. Simpler ROAC catalysts for the facile synthesis of end-functional polyesters is highly desirable.…”