Emulsion-induced ordered microporous films using amphiphilic poly(ethylene oxide)-block-poly(n-butyl isocyanate) block copolymers

• Published in: Journal of applied polymer science Vol. 108; no. 6; pp. 3753 - 3759
• Main Authors: Ishizu, Koji, Makino, Masataka, Hatoyama, Naomasa, Uchida, Satoshi
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.06.2008; Wiley
• Subjects: Applied sciences; emulsion-induced method; Exact sciences and technology; microporous film; Organic polymers; Physicochemistry of polymers; Polymers with particular properties; Preparation, kinetics, thermodynamics, mechanism and catalysts; rod-coil diblock copolymer; water-assisted method; Solvent effect; emulsion-induced method; Film; Complex catalyst polymerization; Ethylene oxide copolymer; Experimental study; microporous film; Porous material; Titanium Complexes; Microporosity; Isocyanate copolymer; Cyclic ether copolymer; Polymeric catalyst; Preparation; Diblock copolymer; water-assisted method; Chloro complex; Formation mechanism; rod-coil diblock copolymer; Growth from solution; Amphiphilic polymer
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.28030

Well-defined poly(ethylene oxide)-block-poly(n-butyl isocyanate) (PEO-block-PBIC; AB) diblock copolymers were prepared with trichloropentadienyl titanium (IV) (CpTiCl₃) catalyst. Ordered microporous films (hexagonal pattern) were constructed by emulsion micelles of A₁₁₀B₂₃₀ diblock copolymer (the subscript indicates the degree of polymerization of each block component) formed from CHCl₃/H₂O/tetrahydrofuran (THF) = 100/5/10 (v/v) solution. The addition of THF promoted uniform micelles in immiscible CHCl₃/H₂O mixed solvent as well as the effect of phase transfer catalyst. Diblock copolymers formed spherical micelles, consisting of a PEO core and a PBIC corona. At some concentration, interaction between micelles forced a disorder-order transition, resulting in freezing of micelles in some superlattice. Subsequently, the leaving gaps among micelles were filled by PBIC block chains on a corona through the evaporation of organic solvents. At last, water within hydrophilic PEO core was vomited through the film matrix. We also constructed the microporous films using A₁₁₀B₂₃₀ diblock copolymer by the current water-assisted method.