Radical copolymerization of acrylic acid and OEGMA475: Monomer reactivity ratios and structural parameters of the copolymer

• Published in: Macromolecular research Vol. 22; no. 12; pp. 1330 - 1336
• Main Authors: Abdollahi, Hossein, Najafi, Vahid, Ziaee, Farshid, Kabiri, Kourosh, Narimani, Farhad
• Format: Journal Article
• Language: English
• Published: Heidelberg The Polymer Society of Korea 01.12.2014; 한국고분자학회
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Nanochemistry; Nanotechnology; Physical Chemistry; Polymer Sciences; Soft and Granular Matter; 고분자공학; alternativecopolymers; monomer reactivity ratios; oligo(ethylene glycol) methyl ether methacrylate; acrylic acid; free radical copolymerization
• ISSN: 1598-5032; 2092-7673
• DOI: 10.1007/s13233-014-2190-y

Alternative copolymers of acrylic acid (AA) and oligo(ethylene glycol) methyl ether methacryate (475 g/ mol (OEGMA 475 )) macromer, having various amounts of two monomers, were synthesized using aqueous solution free radical copolymerization at 50 ±C with ammonium persulfate (APS) as an initiator. The structures of the copolymers were confirmed by nuclear magnetic resonance (NMR) spectroscopy. In fact, samples with different molar ratios of two monomers in deionized water were prepared and subsequently copolymerization reaction was performed to low conversion levels (below 10%). Monomer reactivity ratios of OEGMA 475 , AA pair were estimated using the Finemann-Ross (FR), inverted Finemann-Ross (IFR), Kelen-Tüdös (KT), extended Kelen-Tüdös (EKT), Mayo-Lewis (ML) and Yezrelieve-Brokhina-Roskin (YBR) graphical methods. The value ranged from 0.908 to 0.963 for r OEGMA and from 0.208 to 0.243 for r AA depending on conversion percentage and calculation methods of monomer reactivity ratios. In all the cases, r OEGMA × r AA <1 and r OEGMA > r AA indicate that the resulting copolymer has a tendency toward alternation with an azeotropic point in M OEGMA =0.905. Structural parameters of the copolymers were obtained by calculating the dyad monomer sequence fractions and the mean sequence length.