Load-bearing, structural bonds are especially suitable for the material glass and become increasingly important in glass construction. Examples are bonded point fixings in façades.An essential requirement for this application is the durability of the adhesive joints. In case of façade failure, there is a high danger to people,
so that the risk of this failure must necessarily be reduced. A failure of the joints is often caused by aging. In particular, this occurs when the adhesive is in contact with harmful media, e.g. water or corrosive media like acid rain, seawater and detergents. The joint is penetrated by the harmful media, which results in adhesive failure. Hence, the materials have to be protected from environmental influences. For this purpose, in glass constructions sealing elements with different structures and functions are used.There exist jointing elements without external pressure like sealing compounds and porous or cellular gaskets. In contrast, for point fixings jointing elements with external pressure are applied. These also include O-rings, which are suitable sealing systems for bonded point fixings. O-rings are based on different polymer materials and are available in a wide range of Shore hardnesses. In addition, the
advantages of O-rings lie in their ease of installation, their small space requirement, their low costs and their high impermeability. They are used in many industrial fields and can be selected individually according to the purpose.
O-rings ensure the protection of the adhesive joint but only if they withstand even the aging process and not lose their function over the expected lifetime. Therefore, it was the aim of the study to test O-rings based on EPDM
(ethylene propylene diene monomer rubber), MVQ (methyl vinyl silicone rubber) and NBR (nitrile butadiene rubber) with different Shore hardnesses for their resistance to aging. For this purpose, various artificial aging methods
were used, which considered, in addition to the critical harmful media, also heat and UV aging.