Effect of homopolymer in polymerization-induced microphase separation process. (22nd September 2017)

• Record Type: Journal Article
• Authors: Park, Jongmin; Saba, Stacey A.; Hillmyer, Marc A.; Kang, Dong-Chang; Seo, Myungeun
• Is Part Of: Polymer. Volume 126(2017)
• Page Start: 338
• Page End: 351
• Publication Date: 2017-09-22
• Subjects: Porous polymer -- Block copolymer -- Polymerization-induced phase separation; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2017.04.046
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: We report on the phase separation behaviors of polymerization mixtures containing a polylactide macro-chain transfer agent (PLA-CTA), styrene, divinylbenzene, hydroxyl-terminated PLA (PLA-OH), and a molecular chain transfer agent which enable the ability to tune the pore size of a cross-linked polymer monolith in a facile manner. Cross-linked monoliths were produced from the mixtures via reversible addition-fragmentation chain transfer (RAFT) polymerization and converted into cross-linked porous polymers by selective removal of PLA while retaining the parent morphology. We demonstrate that pore sizes are tunable over a wide range of length scales from the meso- to macroporous regimes by adjusting the ratio of PLA-CTA to PLA-OH in the reaction mixture which causes the phase separation mechanism to change from polymerization-induced microphase separation to polymerization-induced phase separation. The possibility of increasing porosity and inducing simultaneous micro- and macrophase separation was also realized by adjustments in the molar mass of PLA which enabled the synthesis of hierarchically meso- and macroporous polymers. Graphical abstract: Highlights: Porous P(S-co-DVB) is derived by etching of polylactide in the precursor. Pore size is tunable from meso-to macroporous regime. Homopolymer swells domains formed by polymerization-induced microphase separation. Polymerization-induced phase separation occurs upon high loading of homopolymer. Simultaneous micro-/macrophase separation results in hierarchically porous polymer.