How To Enhance The Aging Resistance Of Nylon

Polymer material itself has the structural characteristics and physical state and its use in the process of heat, light, thermal oxygen, ozone, water, acid, alkali, bacteria and enzymes and other external factors make it in the application process, there will be a decline in performance or loss, such as yellowing, relative molecular mass decline, product surface cracking, loss of luster, more serious is to lead to a substantial decline in impact strength, tensile strength and elongation, and other mechanical properties Decrease, and even lose the value of use. This phenomenon is referred to as aging.

Aging in the synthesis of polymer materials, storage, processing and final application of the various stages may occur, can lead to the end of the service life of the material and a large number of waste, resulting in a great waste of resources and serious environmental pollution.

Aging classification of polymer materials

In general, the aging of polymer materials can be categorized into the following four types of changes:

(1) Changes in appearance. Such as the appearance of stains, spots, silver lines, cracks and so on.

(2) Changes in physical properties. Such as changes in quality, size, heat resistance, cold resistance and other performance indicators

(3) Changes in mechanical properties. Such as tensile, flexural, compressive and other performance changes.

(4) Changes in electrical properties. Such as insulation resistance, dielectric loss, breakdown voltage and so on.

Polymer materials and their products in practical applications play a very important role, once the use of aging failure, will inevitably cause economic losses, or worse, may lead to environmental damage, personal injury and death and so on.

Therefore, it is necessary to replace the polymer material products before aging and failure. In both the spirit of energy saving, low carbon and ecological development principles, but also to maximize the function of polymer products, material reliability and durability is becoming more and more people's attention.

Aging of nylon

PA6, PA66 has a light weight, high toughness, electrical insulation and thermal insulation performance is good, etc., widely used in the electronics industry, such as electrical machinery or power tools shell, electrical appliances with tuning parts, machine shells, automobile engine blades.

However, as a basic raw material for electronic devices, it is required that in a certain period of use, not only the mechanical strength to maintain a good, but also require that the appearance and color of the products can not be changed too much after aging, especially some of the appearance of light-colored nylon products with strict requirements, otherwise it will reduce the performance of electronic products, affecting the normal use of the device.

As the indoor use of electronic and electrical PA6, PA66 materials in actual use will face the situation of high local temperature, so the role of long-term heat is to make PA6, PA66 aging of one of the important factors; in the actual use of the environment and conditions, most of the cases will be oxygen involved in the aging process of nylon, heat and oxygen will greatly accelerate the joint role of its aging process. Therefore, it is very necessary to take anti-aging measures for PA6 and PA66.

Reinforcement of nylon anti-aging methods

It has been found that the addition of antioxidants and blend modification can improve the heat aging resistance of PA materials and greatly extend the service life of the materials.

Commonly used reinforced nylons have thermo-oxidative stabilizers, including copper stabilizers, amine and hindered phenol antioxidants, hydroperoxide decomposers and so on.

According to some data and a large number of experiments, the anti-aging effects of different antioxidant systems are as follows: copper salt antioxidant > 1098+626 antioxidant system > 1098 antioxidant system > 1010+626 antioxidant system. Carbon black has good UV absorber, so black reinforced nylon material is more resistant to aging than other color reinforced nylon.

POE-g-MAH elastomers have been found to resist thermal aging to some extent in toughened PA6 systems. The combination of antioxidant 1098 and phosphite antioxidant 626 has a synergistic effect in PA6 systems.

Copper salt antioxidant and antioxidant 1098 and its complex antioxidant are efficient antioxidants for PA6 resin system. Copper salt antioxidant has more obvious anti-heat aging effect on toughened PA6 system. Antioxidant 1010 blended system has limited heat aging effect on PA6 resin. Reinforced nylon with copper salt antioxidant and 1098 compounding platform antioxidant toughened PA6 materials, can meet the thermal oxidative aging requirements of the material.