Miscibility of Poly(vinyl alcohol)/Poly(methacrylic acid) and Poly(vinyl alcohol)/Poly(acrylic acid) Systems: I. High-Resolution NMR Studies in Solution

Abstract

ABSTRACT:Miscibility in two-component polymer systems of poly(vinyl alcohol)jpoly-(methacrylic acid) (PVAjPMAA) and poly(vinyl alcohol)jpoly(acrylic acid) (PVAjPAA) in dimethylsulfoxide (DMSO) solution was examined by high-resolution NMR. Intermolecular NOE was observed between PYA and PMAA or PAA. The results indicate that the PYA and PMAA or PAA are intimately mixed on a scale less than 4A. The chemical shifts of COOH resonances of PMAA and PAA and the OH resonance of PV A suggest the existence of hydrogen-bonding interaction between the two different polymers.

Site-resolved 2H relaxation experiments in solid materials by global line-shape analysis of MAS NMR spectra

“…The method assigns the chemical shifts in the expected order: d methylene > d methyl , with a calculated chemical shift difference of ca 1.1 ppm. In liquids, the corresponding shifts in PMAA are typically given as 0.9-1.0 ppm (for CH 3 ) and 1.7 ppm (for CH 2 ) [29,30]. Hence, the methylene-methyl shift difference is about 0.7 ppm, smaller than that measured here; this variance between liquid and solid states can be easily explained by the different intermolecular environments for the involved groups in neat PMAA solid and in a solvent [31][32][33].…”

Lignosulfonate-based heterogeneous sulfonic acid catalyst for hydrolyzing glycosidic bonds of polysaccharides

“…After a rapid addition of water, free glucose and a proton are liberated. broadening of proton resonances in hydroxyls suggests hydroxyls electronically interact with COOH or OH groups, perhaps via hydrogen bonding [29][30][31], whereas very little change is observed for the peaks of methylene and methine in the cellobiose backbone (shift 4.1-4.4 ppm).…”

Miscibility and interactions in blends of two proton‐donating polymers: Poly(acrylic acid)/poly(p‐vinylphenol) blends

“…However, the miscibility of blends containing two proton‐donating polymers has not attracted much attention. Zhang et al6, 7 reported the miscibility of poly(vinyl alcohol) (PVA)/poly(methacrylic acid) (PMAA) complexes and PVA/PAA blends. PVA and PMAA are miscible on a scale of 2–3 nm because of intermolecular hydrogen bonding.…”