Aging of silicone pressure-sensitive adhesives

Silicone pressure-sensitive adhesives (Si-PSA) exhibit unique properties, such as high Si–O–Si backbone flexibility, low intermolecular interactions, low surface tension, excellent thermal stability, and high UV transparency, which often explains why silicone PSAs have an impressive performance at high- and low-temperature extremes, excellent electrical properties, chemical resistance, and outstanding weathering resistance turning them superior compared to organic PSAs. It is well known that due to their unique properties, silicone pressure-sensitive adhesives are materials for special applications. In the present study, we focus on changing the useful properties of the best compositions of silicone pressure-sensitive adhesives in time to verify the impact of aging on them. The influence of time on given silicone pressure-sensitive adhesive tapes and their useful properties is a very important factor for the description of the life-time of potential products based on such compositions. Aging of Si-PSA was carried out for 1 h, 24 h, 7 days, 31 days, and 92 days. The tests did include such properties like adhesion, cohesion (at 20 and 70 °C), tack, and yellowness.