In recent years, the influence of humidity on polymer materials has been paid special attention. One of its scenes is the influence of humidity factors on the reliability of equipment in the fields of microelectronics and microelectromechanics, such as causing materials to swell and deform, cause cracking, and cracking. Causes stress concentration, etc. The second setting is the aging problem of polymer materials in engineering applications, and aging will reduce the function of polymer materials.
The influence of humidity on engineering plastics
Considering the humidity factor, when the relative humidity is greater than 80%, the moisture in the air penetrates into the material or forms a water film on the surface of the plastic, which will reduce the application function of the plastic; when the relative humidity in the air is less than 100% At 50 o’clock, the moisture contained in the plastic will evaporate into the air, which will also change the function of the plastic, making some plastics brittle and cracking.
The main effect of humidity on the function of engineering plastics is the absorption process. At present, the research on the influence of humidity on the structure and mechanical functions of plastics mainly includes two aspects. On the one hand, the material deformation and residual stress caused by the swelling caused by humidity are studied, including the use of constitutive or numerical simulation methods to study the penetration and dispersion of humidity. The structural stress and interface stress caused by uneven moisture content; on the other hand, the influence of humidity and temperature on the physical properties of plastics, such as the influence on physical functions such as strength, density, modulus, and lifespan, is discussed.
The impact of environmental humidity on the performance of plastic machinery is significant. Generally, plastics that can absorb water are sexual materials. These materials can generally form some kinds of bonds. Such bonds may be hydrogen bonds. Materials such as nylon are such materials. On the other hand, moisture does not have any effect on polyethylene or polytetrafluoroethylene, and the function of these plastics is almost lazy in terms of environmental humidity changes.