In the process of processing, storage and use of polymer materials, due to the comprehensive effect of internal and external factors, its performance gradually deteriorates, resulting in the loss of use value. This phenomenon belongs to the aging of polymer materials.

This not only causes a waste of resources, but even causes greater accidents due to its functional failure, and the decomposition of materials caused by its aging may also pollute the environment.

Due to different types of polymers and different use conditions, they have different aging phenomena and characteristics. In general, the aging of polymer materials can be classified into the following four types of changes:

Changes in appearance
There are stains, spots, silver streaks, cracks, blooming, chalking, stickiness, warping, fish eyes, wrinkles, shrinkage, scorching, optical distortion, and changes in optical color.

Changes in physical properties
Including changes in solubility, swelling, rheological properties, cold resistance, heat resistance, water permeability, and air permeability.

Changes in mechanical properties
Changes in tensile strength, bending strength, shear strength, impact strength, relative elongation, stress relaxation and other properties.

Changes in electrical properties
Such as changes in surface resistance, volume resistance, dielectric constant, and electrical breakdown strength.