Precise Synthesis and Thin Film Self-Assembly of PLLA-b-PS Bottlebrush Block Copolymers

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope photonic and membrane technologies. In this paper, we describe a two-step synthesis poly(l-lactide)-b-polystyrene (PLLA-b-PS) BBCPs their rapid thin-film self-assembly. PLLA chains were grown from exo-5-norbornene-2-methanol via ring-opening polymerization (ROP) l-lactide produce norbornene-terminated PLLA. Norbonene-terminated PS was prepared using anionic followed by termination reaction with exo-5-norbornene-2-carbonyl chloride. PLLA-b-PS these two norbornenyl macromonomers one-pot sequential ring opening metathesis (ROMP). thin-films exhibited cylindrical lamellar morphologies depending on relative volume fractions, domain sizes 46–58 nm periodicities 70–102 nm. Additionally, nanoporous templates produced selective etching blocks structures. findings described in work provide further insight controlled leading various possible for applications requiring periodicities. Moreover, thin film patterning strategy demonstrated (>5 min) highlights advantages BBCP materials beyond linear BCP analogues terms both dimensions achievable reduced processing time.