| 摘要 |
Polyester water-based defoamers are prepared by reaction of a dimer fatty acid, a fatty acid and two different polyalkylene polyols, e.g. polypropylene glycol and polyethylene glycol. The resulting polyesters are readily dispersible in water to form a water-based macroemulsion in the absence of any oil or short chain alcohols. The macroemulsion is an effective defoamer in ground-wood and thermomechanical pulping operations. |
