Surface modification on thermoplastic olefins by low-temperature cascade arc discharge-air plasmas for enhanced adhesion with primer

摘要

Improvement of primer adhesion to thermoplastic olefins (TPOs) by surface modification with a low-temperature cascade are discharge-air plasmas was investigated. Air plasma with a low-temperature cascade are plasma torch can be used for improving the primer adhesion to TPOs. Tape-adhesion tests (ASTM 3359-92a method) demonstrated this improvement with a rating of "0" for untreated TPOs and "5" for air plasma-modified TPOs at certain plasma conditions even for aging at 60 degreesC and 80% relative humidity for 5 days. The adhesion to primer for the soft and flexible kind of TPOs (ETA-3041c and ETA-3101) was easily enhanced. The adhesion to primer for the hard and brittle TPOs (ETA-3183) needs to optimize the plasma conditions to pass the wet-adhesion test using air plasmas. To relate the surface characteristics of air plasma-modified TPOs to adhesion performance with primer, the wettability and polarity of TPOs were evaluated by the contact-angle measurements of primer and deionized water to TPOs. TPO surface morphology was evaluated using scanning electron microscopy. The surface composition was characterized with electron spectroscopy for chemical analysis. (C) 2002 Wiley Periodicals, Inc. [References: 11]