What is the Aging Test ? (part 1)
The aging test mainly refers to the thermal oxygen aging test of rubber, plastic products, electrical insulation materials, and other materials; or the ventilation aging test for electronic parts and plastic products.
Seven aging test methods:
At present, there are many aging test methods for polymer materials, including climate aging test, ultraviolet aging test, ozone aging test, hot air aging test, high and low temperature alternating aging test, damp heat aging test, medium aging test, salt spray aging test, etc..
Climate Aging Test
The so-called climate aging test is a kind of research method that exposes the test samples of polymer materials to atmospheric environmental conditions, so as to obtain the aging law of the material samples exposed to the atmospheric environment, analyze the properties of polymer materials, and predict their service life.
There are two types of climate aging tests
- One of them is the natural exposure test, the polymer material test sample is exposed to the real atmospheric environment to obtain the aging behavior of the material in the real environment. The aging information obtained by this aging test method is the most accurate. The most effective method for the aging behavior of molecular materials, but this test method cycle time is too long, time-consuming, and laborious. People in Florida in the United States, Wanning, Mohe, and Wuhan in China have conducted air exposure tests for more than a year.
- The other is the artificial climate aging test. The artificial climate aging test refers to the aging test method in which people simulate the real atmospheric environmental conditions indoors or strengthen a certain environmental factor to obtain the aging behavior of materials in a short time. It is also called artificial simulated aging or artificially accelerated aging. Artificial climate aging is usually carried out in an artificial climate aging chamber. The commonly used artificial climate aging chambers mainly include xenon lamp climate aging chamber, fluorescent lamp climate aging test chamber, and carbon arc lamp climate aging test chamber. These types of climate aging test chambers simulate or strengthen natural environmental factors from the main climatic factors such as light, temperature, humidity, rain, or condensation to achieve material aging. In addition, the aging test materials should be carried out according to certain test standards.
UV Aging Test
Ultraviolet light in sunlight, because its light energy is equivalent to the bond energy of polymer chemical bonds, can cause the break of the polymer compound chain, which is the main factor leading to the degradation of polymer materials.
The ultraviolet aging test refers to a test method in which the aging test samples of polymer materials are placed in an ultraviolet light field and exposed to obtain the aging behavior and laws of polymer materials.
Generally, the ultraviolet aging test will specify the ultraviolet region and the radiation intensity, such as 40W/m2, in the wavelength range of 300nm-400nm. The light sources used in the UV aging test usually include xenon lamps, fluorescent lamps, tritium lamps, and deuterium lamps. Among them, xenon lamps can simulate the solar spectrum well, and fluorescent lamps can simulate the ultraviolet spectrum of sunlight well. The tritium lamp can provide strong energy, which is generally used for accelerated aging tests.
Ozone Aging Test
Ozone is an extremely rare gas in the atmosphere, but it is extremely destructive to polymer materials. Ozone can have an irreversible chemical reaction with unsaturated bonds and reducing groups in the chemical structure of polymer materials, resulting in oxidative degradation of polymer materials, thus losing the use-value. Especially for rubber materials containing double bonds, it exhibits extremely strong destructive power.
Ozone has strong activity. It can decompose more active atomic oxygen and chemically react with the double bonds in the rubber molecule, causing rubber aging, crack, and become brittle.
The ozone aging test of polymer materials is usually carried out in an ozone aging test chamber. The ozone is provided by an ozone generator and its concentration can be adjusted by mixing with air with a mixer. The concentration of ozone is generally determined according to the environmental conditions in which the material is actually used.
In addition, the temperature, humidity, and other factors in the ozone aging chamber can also be adjusted to achieve the purpose of the test, and obtain the ozone aging resistance of the material and the behavior and law of ozone aging.
Hot Air Aging Test
Heat is one of the main factors that cause the aging of polymer materials. Heat can accelerate the movement of polymer chains, cause polymer chains to break, generate active free radicals, and cause free radical chain reactions to cause polymer degradation or exchange.
The hot air aging test is one of the main test methods for evaluating polymer materials and studying the aging resistance of polymer materials. It is usually carried out in a constant temperature blast drying test chamber.
The temperature in the drying oven can be set according to the test requirements. The polymer materials are regularly sampled and tested when exposed to dryness to obtain the aging behavior and laws of the polymer materials, so as to modify the polymer materials in a targeted manner and improve their performance.
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