People will age and die. Plastics also have an age and life span, and aging will occur. In the process of processing, storage and use, when plastics are exposed to natural or artificial environmental conditions, their properties gradually deteriorate and deteriorate, which is what we often call plastic aging. So, what is the essence of plastic aging, what are the specific manifestations, what causes plastic aging, and how to prevent or delay plastic aging? The following will be analyzed one by one.

    1、 Nature of plastic aging

    Plastic aging is essentially the result of degradation, that is, the number of carbon atoms in molecules is reduced, the molecular weight is reduced, or macromolecules are decomposed into smaller molecules.

    However, plastic degradation is not completely equal to plastic aging. What is discussed here is the impact of plastic aging and deterioration. On the other hand, scientists are also using degradation to reduce or eliminate the environmental pollution caused by waste plastics.

    2、 Aging behavior of plastics

    After a certain period of use, the original performance of plastic products deteriorates, which eventually affects or even loses the use value. This is the signal of plastic aging, which generally has the following manifestations.

       1. Strength reduction, 2. Embrittlement, 3. Fracture, 4. Softening, 5. Loss of mechanical strength, 6. Hardening

    3、 Causes of plastic aging

    There are many reasons for plastic aging. Generally speaking, plastic aging is the result of the comprehensive influence of internal and external factors.

    On the one hand, this is determined by the molecular properties of plastics themselves. Unsaturated double bonds, branched chains, carbonyl groups and hydroxyl groups at the end of plastic molecular chains are easy to cause aging, and will degrade to a certain extent over time. In the process of degradation, the degradation products form free radicals, which makes the molecular chain chain react, and will accelerate the degradation rate.

    On the other hand, under the influence of environmental and external factors, such as sunlight, oxygen, heat, water, radiation, industrial gases, molds, bacteria, insects, etc., the internal molecular weight of plastics changes, resulting in aging.

    It is worth noting that plastics are synthetic polymer compounds, and other substances need to be added in addition to the main component resin. Due to the structural differences of different material chains, as well as different constituent substances and production technology, the aging speed of plastics is also different.

    4、 How to delay the aging of plastics and prolong the service life of plastics

    Although the aging problem is an irreversible process and inevitable, are there any methods to delay the aging of plastics and prolong their service life? The answer is yes, mainly in the following points.

      1. Improve the strength and heat resistance of plastics through fillers, which are mainly divided into organic fillers and inorganic fillers, the former such as wood powder, rags, paper and various fabric fibers, and the latter such as glass fiber, diatomite, asbestos, carbon black, etc.

      2. Add plasticizer to enhance the plasticity and softness of plastics, reduce brittleness and make plastics easy to process and shape.

      3. Add stabilizers, such as stearate and epoxy resin, to prevent the decomposition and damage of synthetic resin by light and heat during processing and use, and prolong the service life.

      4. Add antioxidant to prevent the plastic from yellowing and cracking due to thermal oxidation during heating forming or high-temperature use.

      5. Add mold inhibitor to prevent corrosion by bacteria, molds and other microorganisms.

      6. Add flame retardant, foaming agent, antistatic agent, etc. according to the specific requirements of parts to meet different use needs.

      7. Add colorants and lubricants to make the plastic have a variety of bright and smooth appearance, and can also delay the aging of the plastic to a certain extent.

      8. Add antistatic agent to give the plastic light to medium conductivity and prevent the accumulation of static charge.

      9. Adopt physical methods, such as electroplating, painting, coloring, packaging, etc., to delay degradation to a certain extent.

      10. Pay attention to daily maintenance, inspection and maintenance and regular replacement to nip the hidden dangers and accidents caused by plastic aging in the cradle.