2021.07.17aging phenomenon of plastics
People will age and die, and plastics will also have an age life span, and they will age. In the process of processing, storage, and use, when plastics are exposed to natural or artificial environmental conditions, their performance gradually deteriorates and deteriorates, which is what we often call plastic aging. So, what is the nature 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. The nature of plastic aging
Plastic aging is essentially the result of degradation, that is, the number of carbon atoms in the molecule decreases, the molecular weight decreases, or large molecules are broken down into smaller molecules.
However, plastic degradation is not completely equivalent to plastic aging. What is discussed here is the impact of plastic aging and degradation on use. On the other hand, scientists are also using degradation to reduce or eliminate environmental pollution caused by waste plastics.
Second, the performance of plastic aging
After a certain period of use of plastic products, the original performance will deteriorate, which will eventually affect or even lose the use value. This is a signal of plastic aging, and generally has the following performance.
1. Decrease in strength, 2. Brittle, 3. Fracture, 4. Softening, 5. Loss of mechanical strength, 6. Hardening
Three, the cause 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 nature of the plastic itself. Unsaturated double bonds, branched chains, carbonyl groups, and hydroxyl groups at the end contained in the plastic molecular chain are all components that are prone to aging and will be degraded to a certain extent over time. In the degradation process, the degradation products form free radicals, which causes the molecular chain to undergo a chain reaction, which will accelerate the degradation rate.
On the other hand, affected by the environment 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, in addition to the main component resin, other substances need to be added. Due to the difference in the structure of different material chains, as well as different composition materials 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 some ways to delay the aging of plastics and prolong its service life? The answer is yes, mainly as follows.
1. Improve the strength and heat resistance of plastics through fillers. They are mainly divided into organic fillers and inorganic fillers. The former include wood flour, rags, paper and various fabric fibers, and the latter such as glass fiber, diatomaceous earth, and asbestos. , Carbon black, etc.
2. Add plasticizers to enhance the plasticity and softness of plastics, reduce brittleness, and make plastics easier to process and shape.
3. Add stabilizers, such as stearate, epoxy resin, etc., to prevent the synthetic resin from being decomposed and damaged by light and heat during processing and use, and prolong the service life.
4. Add antioxidants to prevent the plastic from being heated and oxidized during heat molding or high-temperature use, which will cause the plastic to turn yellow and crack.
5. Add anti-mold agent to prevent corrosion by bacteria, mold and other microorganisms.
6. According to the specific requirements of the parts, add flame retardants, foaming agents, antistatic agents, etc. to meet different requirements.
7. Add colorants and lubricants to make the plastic have a variety of bright and smooth appearance, and it can also delay the aging of the plastic to a certain extent.
8. Add antistatic agent to give the plastic mild to medium conductivity and prevent the accumulation of static charge.
9. Use physical methods, such as electroplating, painting, coloring, packaging, etc., to delay degradation to a certain extent.
10. Pay attention to daily maintenance, inspection and repair, and regular replacement, so as to suppress the hidden dangers caused by plastic aging in the cradle.key words：aging phenomenon of plastics China aging phenomenon of plastics
Qingdao Yishibao Plastic Co., LTD
133 9532 2932 / 133 0639 9338
Zaohu Community , Chengyang Street ,
Chengyang District , Qingdao City
133 9532 2932 / 133 0639 9338