Several Anti-aging Methods Commonly Used in Plastic Materials and Comparative Analysis

【Chinese Packaging Network News】 Polymer materials have in fact become a necessity in every aspect of modern life. The latest progress in production and processing has further broadened the scope of application of plastics. In some applications, polymer materials even Replaced 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 such as heat, light, thermal oxygen, ozone, water, acid, alkali, bacteria, and enzyme that are used in the course of its use make it possible during the application process. Loss of performance or loss, such as yellowing, decrease in relative molecular mass, cracking of the surface of the product, loss of gloss, and more severely result in a significant decrease in mechanical properties such as impact strength, tensile strength, and elongation, thereby affecting the polymer material. Normal use.

This phenomenon is simply referred to as aging. Aging can occur at all stages of synthesis, storage, processing, and final application of polymer materials. It can lead to the end of service life and large amounts of waste, resulting in great waste of resources and serious environmental pollution. The aging of polymer materials during use is more likely to cause great disasters and irreversible losses.

Therefore, the aging of polymer materials has become a problem that the polymer industry has to solve. In fact, the anti-aging of polymer materials is an important issue in polymer chemistry. At present, the main methods for improving and improving the anti-aging properties of polymer materials are as follows:

1, physical protection (such as thickening, painting, outer composite, etc.)

Aging of polymer materials, especially photo-oxygen aging, begins with the surface of the material or product, which is characterized by discoloration, chalking, cracking, and a decrease in gloss, and gradually deepens into the interior. Thin products are more prone to early failure than thick products, so the product's life can be extended by thickening the product.

For easily aging products, a layer of weatherable coating may be coated or coated on the surface of the product, or a layer of weather-resistant material may be compounded on the outer layer of the product so as to attach a protective layer to the surface of the product. Delay the aging process.

2, improve the processing technology

Many materials also suffer from aging problems during their synthesis or preparation. For example, the effect of heat during polymerization, thermal oxygen aging during processing, and so on. Correspondingly, the effect of oxygen can be mitigated by adding an oxygen removing device or a vacuuming device during the polymerization or processing.

However, this method can only guarantee the performance of the material at the time of shipment, and this method can only be implemented from the source of the material preparation and cannot solve the problem of aging during reprocessing and use.

3, structural design or modification of polymer materials

Many molecular structures of macromolecules have extremely aging groups. Therefore, by designing the molecular structure of the material, replacing the easily-aging groups with groups that are not susceptible to aging can often provide good results.

4, add anti-aging additives

At present, an effective way to improve the anti-aging properties of a polymer material and a commonly used method is to add an anti-aging aid, which is widely used due to its low cost and without changing the existing production process. There are two main ways to add these anti-aging additives:

(1) Direct Additives

The anti-aging aids (powder or liquid) and raw materials such as resins are mixed, stirred, extruded, pelletized or injection molded. This type of addition is simple and easy to use, and is widely used by the majority of pumping and injection molding plants.

(2) Anti-aging masterbatch addition method

Manufacturers with higher requirements on product quality and quality stability are more likely to adopt anti-aging masterbatches at the time of production.

Its application advantage is that the anti-aging aid first realizes the pre-dispersion in the preparation process of the masterbatch, and then the anti-aging aid is secondarily dispersed in the later material processing process, and the aid is evenly dispersed in the matrix of the polymer material. The purpose is not only to ensure the stability of the product quality, but also to avoid dust pollution during production, making the production more green and environmentally friendly.

The comparison of the two addition methods is shown in the following table:

Based on the above analysis, we recommend using anti-aging masterbatch to improve the quality of the material when using anti-aging additives.