First, the inherent factors of commodity aging

Material type

The so-called material type refers to the chemical structure of the product itself. Such as polypropylene containing tertiary carbon atoms, the plastic products and polypropylene fabric aging resistance is not as good as polyethylene

Structure of macromolecule chains

The macromolecule chain structure includes relative molecular weight, irregular structure, relative molecular weight distribution, degree of branching, bulk length and so on. Among them, the irregular structure such as branch, double bond, end base, etc., often referred to as the main chain of weaknesses, the impact of the aging of goods greater impact. Such as polyvinyl chloride, from the chemical structure point of view is not easy to break down. But in fact its thermal stability is very poor, the product can only be used below 70 ℃

Ingredients

Plastic products in the production are often based on different uses, add other additives, such as plasticizers, fillers, colorants, stabilizers and so on. Rubber products to join the curing agent, accelerators, antioxidants, fillers, softeners and other complex agent. If these additives and improper use of improper, will also promote the aging of goods. Such as the vulcanization agent (sulfur) added in the general rubber products, the vulcanized rubber of the single sulfur and the disulfide crosslinked structure has better oxidation capacity and the polysulfide crosslinked structure vulcanizate is quite poor in oxidation resistance, under suitable conditions Will split the free radicals, triggering automatic catalytic oxidation reaction, so that the goods accelerated aging

Forming processing

In the processing of goods, raw materials by different external temperature and pressure role, so that internal changes have taken place, such as crystallinity, crystal structure, grain size, macromolecule orientation and so on. Therefore, the aging resistance of polymer products and their manufacturing methods and processing conditions are also related

Second, the environmental factors of commodity aging

Daylight

Daylight is one of the most important factors affecting the aging of goods. On the aging of goods has a significant impact on the ultraviolet, infrared, visible light on the aging of goods also have an impact

Heat

Heat is an important factor in the aging of polymer products. Thermal aging is one of the important aging products in storage. The alternating effects of cold and heat in the atmospheric environment will also have some effect on the aging of the commodity

Oxygen and ozone

Polymer materials are very sensitive to the molecular oxygen in the atmosphere, and even the role of trace oxygen, can make some of the tensile strength, hardness, elongation and other properties of serious changes. All the polymer materials are very sensitive to oxygen in the air. Ozone concentration in the atmosphere is not high, but the impact on the goods, especially under the action of sunlight, due to the activation of light, will accelerate the speed of ozone aging, so that the aging of goods more strongly