| abstract |
Dispersing agents useful in a suspension polymerization process may be formed based on polyvinyl alcohols and processes discloses herein. The dispersing agent may include, for example: a polyvinyl alcohol having a degree of hydrolysis in the range from 60 to 80 mol%; an absorbance of not less than 0.3 measured at a wavelength of 320 nm with respect to a 0.1 wt% aqueous solution of the polyvinyl alcohol; a block character of remaining ester groups in the range from 0.4 to 0.5; and a cloud point in the range from 35°C to 50°C measured with respect to a 1 wt% aqueous solution of the polyvinyl alcohol. Carbonyl groups are theorized to be present along the polymer chain, which may be quantified by 1-H NMR spectra peaks. |