Durability of the effectiveness of atmospheric plasma treatment applied to thermoplastic Styrene-Butadiene-Styrene (SBS) rubber

• Published in: The Journal of adhesion 2025-01, Vol.101 (1), p.164-190
• Main Authors: Ruzafa-Silvestre, C., Serrano-Martínez, V.M., Arán-Ais, F., Orgilés-Calpena, E.
• Format: Article
• Language: English
• Subjects: adhesion performance; atmospheric air plasma; plasma treatment; storage time; surface energy; Surface properties; surface roughness; thermoplastic rubber
• ISSN: 0021-8464; 1545-5823
• DOI: 10.1080/00218464.2024.2303441

The study examines the impact of atmospheric air plasma treatment on Styrene-Butadiene-Styrene (SBS) thermoplastic rubber. The durability of the modifications and their effect on adhesive properties were evaluated over 21 days, with and without adhesive, under specific temperature and humidity conditions (23°C, 50% Relative Humidity). Adhesion performance of plasma-treated SBS rubber joints using water-based polyurethane adhesive (WPU) was assessed, considering treatment speed, adhesive application after plasma treatment, and storage time. Results show that plasma treatment increases SBS rubber's surface energy, introduces roughness, and creates polar functional groups, enhancing adhesion. However, adhesion values varied with treatment speed, immediate adhesive application after plasma treatment, and storage time. Samples treated solely with plasma and without adhesive exhibited declining adhesion over time. Conversely, samples with adhesive applied directly after plasma treatment maintained relatively constant adhesion, slightly decreasing over time. The findings stress the importance of optimising plasma treatment parameters and considering various factors to ensure long-lasting and reliable adhesion of SBS rubber materials for footwear applications. Atmospheric air plasma treatment impacts adhesion in SBS rubber, depending on factors like treatment speed, adhesive timing, and storage, emphasizing the need for optimisation.