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

• Published in: Macromolecules Vol. 47; no. 24; pp. 8709 - 8721
• Main Authors: Chiou, Chin-Wei, Lin, Yung-Chih, Wang, Lei, Maeda, Rina, Hayakawa, Teruaki, Kuo, Shiao-Wei
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 23.12.2014
• Subjects: Applied sciences; Exact sciences and technology; Inorganic and organomineral polymers; Physicochemistry of polymers; Preparation; Silsesquioxane polymer; Thermal transition; Asymmetric molecule; Temperature effect; Composition effect; Silsesquioxane copolymer; Experimental study; Methyl methacrylate copolymer; Phenolic resin; Macromer; Intermolecular interaction; Monodispersed polymer; Polyhedral molecule; Domain structure; Morphology; Preparation; Diblock copolymer; Anionic copolymerization; Methacrylate copolymer; Hydrogen bond; Modified material
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma502180c

Poly(methyl methacrylate)-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.