화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.19, 8921-8936, 2020
Nitroxide-Mediated Miniemulsion Polymerization of Bio-Based Methacrylates
Nitroxide-mediated homopolymerization and statistical copolymerization of commercially available methacrylates derived from sustainable feedstocks (isobornyl methacrylate (IBOMA) and a mixture of methacrylic esters with an average alkyl side chain length of 13 units (termed C13MA)) was conducted in organic solvent (toluene) and in dispersed aqueous media using an oil-soluble unimolecular initiator (Dispolreg 007) without any controlling comonomers in a controlled manner. IBOMA homopolymerization in emulsion at 83-100 degrees C revealed the optimal polymerization temperature of 90 degrees C giving relatively narrow molecular weight distributions (1.46 < dispersities (D) < 1.58) and conversion up to 83% in a relatively short time (2 h). IBOMA/C13MA statistical copolymerizations yielded copolymers with tunable glass transition temperature (T-g) prepared in emulsion (-52 degrees C < T-g < 123 degrees C) and in organic solvent (-40 degrees C < T-g < 169 degrees C). Resins made in emulsion at 90 degrees C proceeded up to 92.7% conversion with monomodal molecular weight distributions (M-n up to 68,000 g mol(-1) and D = 1.62-1.72) and were colloidally stable (24% solids and final average particle sizes of 270-481 nm). Furthermore, chain end fidelity was verified by chain extensions with IBOMA and C13MA monomers in both emulsion and organic solvent. These results constitute a readily scalable route to make polymers via nitroxide-mediated polymerization with controlled architecture using biobased feedstocks without the hazards of bulk or homogeneous organic solvent polymerization.