Mechanical and surface hardness properties of ultraviolet-cured polyurethane acrylate anionomer/silica composite film

An organic-inorganic composite was prepared by mixing silica emulsion with urethane acrylate anionomer (UAA) emulsion. The silica emulsion was prepare d by sol-gel process, and stabilized by a steric stabilizer, polyvinyl pyrr olidone. UAA/silica composite film was made by an ultraviolet curing method . The mechanical and rheological properties of the UAA/silica composite wer e greatly improved. This composite also showed thermal stability during inc rease of temperature. Surface hardness was improved with increasing silica content up to proper amount of silica. However, in abrasive test, because U AA/silica composite film has a more abrasive contact area than UAA film, th e former was abraded much more than the latter. In comparison to UAA film, the UAA/silica composite showed much smoother abrasive surface and less rou ghness. (C) 2000 John Wiley & Sons, Inc.