Adhesive aging refers to the changes in the properties of materials or bonded joints over time. Factors affecting adhesive aging include mechanical stress, temperature, radiation, and the environment. Aging is the result of several factors working together, but these influencing factors are difficult to measure and predict comprehensively.

1、The impact of solvents on adhesives

    Corrosion of the substrate is closely related to the adhesion of adhesive joints to metal substrates that are exposed to moisture absorption. Substrate corrosion leads to rapid failure of adhesive joints in the short term, making corrosion a critical aspect. For example, in different solvent environments such as salt, acid, and alkali. Additionally, moisture can penetrate (diffuse) into cured adhesive layers and be absorbed by the adhesive layer. This absorbed moisture reduces the strength of the adhesive.

    The most significant issue arising from adhesive joints exposed to moisture is the reduction in the adhesion between the substrate and the adhesive. Chemical bonds formed between the adhesive and the substrate surface are more water-resistant than physical interactions. Once the chemical bonds are disrupted, the adhesive strength cannot be restored after drying.

2、The Impact of the Environment on Adhesives

    The primary factor affecting chemical reactions is temperature. The higher the temperature, the more likely chemical reactions are to occur, and they typically occur at a faster rate. Such reactions often lead to changes in the performance of adhesives. Mechanical stress on bonded joints is significantly accelerated under high-temperature conditions, so generally, as the operating temperature increases, the adhesive aging process speeds up. Radiation is also one of the influencing factors that contribute to adhesive aging.

3、The Impact of Mechanical Stress on Adhesives

    The adhesive bonding surface may experience the following types of mechanical stress:

    A. Peel stress

    B. Tensile stress

    C. Shear stress

    D. Torsional stress