Spreading and adhesion of ASA on different surfaces present in paper machines

SUMMARY: The spreading kinetics and adhesion of liquid alkenyl succinic anhydride (ASA) on different surfaces representing materials commonly used in paper machinery (steel, polyurethanes), a possible antifouling material (polytetrafluoroethylene), materials in paper products (cellulose, starch) and two model surfaces (silica and hydrophobed silica) was studied. Contact angles were measured both in air and in aqueous environment. The contact angle of ASA on all solids in air was ″90 o ; ASA generally spread better on hydrophilic surfaces than on hydrophobic surfaces. For ASA on solids immersed in water the trend was opposite to that in air and the difference between hydrophilic and hydrophobic surfaces was much greater; on hydrophilic surfaces the contact angle was ⊕170°, while on hydrophobic surfaces the contact angle was 25°‐50°. However, one material (polyurethane 2) didn’t follow the general trend; even though this material was very hydrophilic, spreading of ASA on it in air was similar to what it was on hydrophobic materials. Combined effect of pH and Ca 2+