Characterization of partially hydrolyzed poly(vinyl alcohol). I. Sequence distribution via H-1 and C-13-NMR and a reversed-phased gradient elution HPLC technique

In this investigation, characterization of the microstructure of three diff erent PVA samples in terms of their degrees of blockiness were performed vi a 125 MHz C-13-NMR and 500 MHz H-1-NMR measurements. Differences between th ese PVAs were also discernable by using a high-performance liquid chromatog raphic technique employing a reverse-phase separation mechanism. The result s obtained from these studies reveal small but significant differences betw een the PVAs, which allow a better understanding of the role of these PVAs in the grafting reactions occurring during the emulsion polymerization of v inyl acetate (VAc) using PVA as emulsifier.