Synthesis of Comb-Like Macromolecules via Semi-Batch Miniemulsion RAFT Polymerizations

Construction of macromolecule topology and control of chain sequence are foundations to endow macromolecules with complex functionalities. Comb-like macromolecules have more designable freedom because their backbones and branched chains can be independently designed and synthesized. Herein, the rigid backbones of comb-like macromolecules are synthesized by ring-opening metathesis polymerizations of norbornene derivatives anchoring reversible addition-fragmentation chain transfer (RAFT) agent. The gradient branched chains with controlled sequence structure are synthesized through a modified RAFT miniemulsion polymerization of 4-vinylpyridine and t-butyl acrylate in a semi-batch manner. These comb-like macromolecules self-assemble into aggregates when a dilute solution of comb-like macromolecules are brushed onto a silicon wafer. The self-assembly behavior of comb-like macromolecules is affected by grafting ratio and sequence structure of branched chains. The effect of these comb-like macromolecules on water contact angle of silicon wafer is also studied.