Highly Ordered Cylinder Morphologies with 10 nm Scale Periodicity in Biomass-Based Block Copolymers

Abstract

Microphase-separated structures of block copolymers (BCPs) have attracted considerable attention for their potential application in the bottom-up fabrication of 10 nm scale nanostructured materials. To realize sustainable development within this field, the creation of novel BCP materials from renewable biomass resources is of fundamental interest. Thus, we herein focused on maltoheptaose-b-poly(δdecanolactone)-b-maltoheptaose (MH-b-PDL-b-MH) as a sustainable alternative for nanostructure-forming BCPs, in which both constitutional blocks can be derived from renewable biomass resources, in the case, δ-decanolactone and amylose. Well-defined MH-b-PDL-b-MHs with varying PDL lengths were synthesized through a combination of controlled/living ring-opening polymerization and the click reaction. The prepared MH-b-PDL-b-MHs successfully self-assembled into highly ordered hexagonal cylindrical structures with a domainspacing of ∼12−14 nm in both the bulk and thin film states. Interestingly, the as-cast thin films of MH-b-PDL-b-MHs (with PDL lengths of 9K and 13K) form horizontal cylinders, with thermal annealing (180 °C, 30 min) resulting in a drastic change in the domain orientation from horizontal to vertical. Thus, the results presented herein demonstrated that the combination of oligosaccharides and biomass-derived hydrophobic polymers appears promising for the sustainable development of nanotechnology and related fields.

Biosynthesis of Random-Homo Block Copolymer Poly[Glycolate-ran-3-Hydroxybutyrate (3HB)]-b-Poly(3HB) Using Sequence-Regulating Chimeric Polyhydroxyalkanoate Synthase in Escherichia coli

“…In general, characteristic and useful properties of block copolymers are attributable to the linkage between segments with contrasting properties, such as soft and hard segments ( Lendlein et al, 1998 ). In fact, studies on chemically synthesized block copolymers typically select segments with distinct structures; for example, polyester and polysaccharide segments ( Isono et al, 2018 ). PHAs were also chemically conjugated with PHAs ( Dai et al, 2009 ) and/or other types of polymers, such as poly(ε-caprolactone), to improve the flexibility of the material ( Saad et al, 1999 ).…”

Turning natural δ-lactones to thermodynamically stable polymers with triggered recyclability

“…δ-dodecalactone, 28 PEG and ω-pentadecalactone, 29 lactide, 30 methylene diphenyl diisocyanate, 10 1,4 butylene oxide, 14 δ-valerolactone 31 and maltohepotaose. 32 δDL occurs naturally in fruits 33 and milk, 34 but can also be produced enzymatically on large scale from fatty acids and essential oils. 35,36 Recently, it was shown that catalytic transfer hydrogenation 37 could be a new and interesting course to synthesize the monomer, which also increases the potential of establishing δDL as a biobased platform monomer.…”

Sweet Pluronic poly(propylene oxide)-b-oligosaccharide block copolymer systems: Toward sub-4 nm thin-film nanopattern resolution

“…In our previous investigations, we have found that oligosaccharides are useful building blocks for designing BCPs capable of self-assembling into microphase-separated structures of sub-10 nm domain size [36][37][38][39][40][41]. In these systems, the strong hydrophilicity imparted by the presence of multiple hydroxyl groups results in oligosaccharide-containing amphiphilic BCPs with high χ values, and the rigidity of the carbohydrate backbone further enhances the incompatibility of the hydrophilic block with the hydrophobic block.…”