Hydrogen Bond Interactions Mediate Hierarchical Self-Assembly of POSS-Containing Block Copolymers Blended with Phenolic Resin

Abstract

P o l y( me t h y l m et h a c r y l a t e ) -b -poly-(methacryloyl polyhedral oligomeric silsesquioxane) (PMMA-b-PMAPOSS) block copolymers of various compositions were prepared through anionic living polymerization. We employed differential scanning calorimetry, Fourier transform infrared spectroscopy, small-angle X-ray scattering, transmission electron microscopy, and wide-angle X-ray diffraction to investigate the miscibility, specific interactions, and hierarchical self-assembly of PMMA-b-PMAPOSS block copolymers blended with a phenolic resin. We found that the added phenolic resin interacted preferentially with the PMMA blocks through hydrogen bonding between the OH groups of the former and the CO groups of the PMAPOSS. In other words, the OH groups of the phenolic resin did not interact with the CO groups of the PMAPOSS blocks, resulting in their immiscibility. Accordingly, this phenolic/PMMA-b-PMAPOSS blend behaved as a blend of homopolymer C and immiscible A-b-B diblock copolymer, where C is immiscible with B but interacts favorably with A; therefore, it displayed an order−order phase transition with increased phenolic resin content. Hierarchical self-assembly led to the formation of hexagonally packed cylindrical or lamellar nanostructures through microphase separation of the diblock copolymer segment, with POSS aggregates packing into a hexagonal lattice oriented perpendicular to the direction of the nanostructures.

Multiple hydrogen bonding mediates the formation of multicompartment micelles and hierarchical self-assembled structures from pseudo A-block-(B-graft-C) terpolymers

“…[41][42][43] Onion-like microspheres have received much attention due to their potential application as carriers for controlled-release systems; 44 onion-like morphologies have been reported widely in the bulk state, formed from triblock copolymers, copolymer/homopolymer blends, and copolymer/copolymer blends, where thermodynamic equilibrium plays an important role. 45,46 In this study, we observed onion structures of various sizes and with different numbers of ring patterns [ Fig. 9(a)].…”

Sub-10-nm patterning process using directed self-assembly with high χ block copolymers

“…PMMA-b-PMAEtPOSS and PMMA-b-PMAIBPOSS were synthesized by living anionic polymerization. 17,18 The domain sizes of microphase separation listed in Table 1 were obtained by bulk small angle x-ray scattering measurements. As the NL material, polymethylmethacrylate-r-polymethacryli-buty lPOSS-r-polyglycidylmethacrylate (PMMA-r-PMAIBPOSSr-PGMA) was utilized.…”

POSS-derived mesoporous ionic copolymer–polyoxometalate catalysts with a surfactant function for epoxidation reactions

“…They have unique star-shaped nanostructures and chemical properties, such as facile chemical modification, 55 good pH tolerance, high temperature and oxidation resistance properties [21][22][23] . So far, micro/mesoporous materials based on POSS precursors have been prepared by various chemical routes including hydrosilation methods, thermolysis, and coppermediated coupling [24][25][26][27] . However, there are little reports on the 60 preparation of POSS-derived micro/mesoporous poly(ionic liquid) materials for catalysis.…”