Physicochemical study by multi-angle light scattering of water-soluble methacryloylaminophenylarsonate copolymers

• Published in: Journal of polymer research 2014-08, Vol.21 (8), p.1-11, Article 492
• Main Authors: Soriano-Moro, Guillermo, Percino, Judith, Cerón, Margarita, Castro, María Eugenia, Chapela, Víctor M.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Coils; Copolymers; Gyration; Industrial Chemistry/Chemical Engineering; Light scattering; Original Paper; Polyelectrolytes; Polymer Sciences; Size exclusion chromatography; Sodium
• ISSN: 1022-9760; 1572-8935
• DOI: 10.1007/s10965-014-0492-6

The properties of aqueous solutions of polyelectrolytes of sodium o - and p -methacryloylaminophenylarsonate ( o - and p - MAPHA-Na) with acrylamide (AAD) or sodium methacrylate (MA-Na): poly(sodium o -methacryloylaminophenylarsonate) (poly( o -MAPHA-Na)), poly(sodium o -methacryloylaminophenylarsonate- co -acrylamide) (poly( o -MAPHA-Na- co -AAD)) (26:74), poly(sodium o -methacryloylaminophenylarsonate- co -sodium methacrylate) (poly( o - MAPHA-Na-co-AM-Na) (35:65) and (14:86), and poly(sodium p -methacryloylaminophenylarsonate- co -sodium methacrylate) (poly( p - MAPHA-Na-co-AM-Na)) (34:66) were studied by off-line, multi-angle light scattering, and in-line using size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) and refractometric (RI) detection. The M w value corresponding to the homopolymer poly( o -MAPHA-Na) was 1,300,000 g/mol and for the copolymers the M w and gyration radius values were decreased when the AAD or AM-Na comonomer composition increased. The macromolecular parameters obtained using SEC-MALS were in agreement with the values measured in the off-line mode. Also, SEC-MALS experiments allowed examination of the radius of gyration-M w relationship in order to determine the polyelectrolyte conformation (ρ) in solution; these values fell between 0.7-0.53, indicating that the polyelectrolytes are random coils at θ -conditions. In addition, the effect of the pH on the macromolecular parameters was evaluated. At pH 4.5, the M w and gyration radius values corresponding to poly( o -MAPHA-Na) and poly( o -MAPHA-Na- co -AAD) (26/74) remained very close to those measured at pH 7. However, < r g 2  > values for poly( o -MAPHA-Na- co -AM-Na) copolymers at pH 4.5 were less than pH 7, indicating that the presence of AM-Na reduced the size of the copolymer through intermolecular interactions.