In fact, polymer materials have become a necessity in every aspect of modern life. The latest progress in production and processing has further widened the scope of application of plastics. In some applications, polymer materials even replace other materials, Such as glass, metal, paper and wood.
However, the structural characteristics and physical state of the polymer material itself and the external factors of heat, light, hot oxygen, ozone, water, acid, alkali, bacteria and enzymes in the process of using the same Such as yellowing, decrease of relative molecular mass, loss of surface appearance and loss of gloss, and more serious impact on the mechanical properties such as impact strength, tensile strength and elongation, which may affect the performance of polymer materials The normal use.
This phenomenon is simply called aging. Aging can occur in all stages of the synthesis, storage, processing and final application of polymer materials. It can lead to the end of material life and a large amount of waste, resulting in tremendous waste of resources and serious environmental pollution. Aging that occurs during use of polymer materials is more likely to result in catastrophic and irreparable damage.
Therefore, the anti-aging polymer materials have become the polymer industry have to solve the problem.In fact, the polymer anti-aging polymer chemistry is an important issue.At present, to improve and enhance the anti-aging properties of polymer materials mainly There are four ways:
1, physical protection (such as thickening, painting, the outer compound, etc.)
The aging of polymer materials, especially photooxidation, begins with the surface of the material or the product, which manifests itself in discoloration, chalking, cracking, gloss reduction and the like, and then gradually penetrates into the interior. Thin products are easier than thick products Early failure, so thickened products through the method can extend the life of products.
For aging products, the surface can be coated or coated with a layer of weatherable coating, or the outer layer of the product is weighed with a weatherable material, so that the surface of the product attached to a protective layer, so that Slow down the aging process.
2, improve the processing technology
Many materials in the synthesis or preparation process, there are also aging problems, such as the polymerization process, the impact of heat, the process of thermal oxygen aging, etc. Accordingly, by adding polymerization or processing deaerator Or vacuum device to reduce the impact of oxygen.
However, this method can only guarantee the performance of the material at the time of delivery. Moreover, this method can only be implemented from the material preparation source and can not solve the problem of aging during re-processing and use.
3, the structural design of polymer materials or modified
Many polymer materials in the molecular structure of the very easy to aging groups, then through the molecular structure of the material design, easy to replace the aging group easy to aging groups, often can play a good effect.
4, add anti-aging additives
At present, the effective way to improve the aging resistance of polymer materials and common methods is to add anti-aging additives, which due to lower cost, and without changing the existing production process has been widely used.The addition of these anti-aging additives mainly include Two kinds:
(1) additive direct addition method
The forthcoming anti-aging additive (powder or liquid) and resin and other raw materials directly after mixing extrusion granulation or injection molding, etc. This addition as a simple and easy, so for the majority of pumping and injection molding plant widely used.
(2) anti-aging masterbatch addition method
In the product quality and quality requirements of the higher stability of the manufacturers, more is the use of anti-aging masterbatch in the production of ways to add.
Its application advantage lies in the anti-aging agent in the masterbatch preparation process to achieve the first pre-dispersion, then in the latter part of the material processing, anti-aging additives were secondary dispersion, to achieve a uniform dispersion of additives in the polymer matrix The purpose, not only to ensure the quality of the product stability, but also to avoid the production of dust pollution, making the production of more green.
The comparison between the two methods is shown in the following table:
Based on the above analysis, we recommend that when using anti-aging additives, as much as possible the use of anti-aging masterbatch to improve the quality of the material.