Today, I will explain to you some of the major reasons for the aging of silicone tubes.
Contact medium aging
The silicone molecular tube is exposed to the silicon molecular material used in the natural environment, and is aging due to moisture or other conditions in the air. For example, the external insulation material of the power system is highly susceptible to salt spray in salt-soil areas, so it is necessary to carry out aging research to analyze the aging performance under such conditions. In addition, some silicone rubber products in contact with oils, testing their oil resistance and improving their oil resistance are also the focus of practical research.
Thermo-oxidative aging
Silicone rubber mainly undergoes oxidative decomposition reaction of side chain organic groups in an aerobic high temperature open environment, resulting in hardening of silicone rubber. In an oxygen-free high temperature closed environment, main chain framing reaction occurs mainly to form volatile cyclic polycondensation. Silicone, which causes the silicone article to soften. Silicone rubber mainly undergoes side chain methyl group oxidation reaction and main chain degradation cleavage reaction under high temperature conditions.
The four major aging of silicone tube
Fatigue aging
The fatigue aging of silicone tube refers to the aging phenomenon of the change of molecular structure of silicone rubber products after being subjected to certain frequency and periodic stress. It is the result of activation of two main factors, namely force and heat (due to rubber in When the deformation is repeated multiple times, hysteresis occurs, which causes the heat generated inside the silica gel to act as a result.
Ozone aging
Ozone is extremely low in the atmosphere. During the aging process of silica gel, ozone attacks the fine molecules of silica gel, causing the silica gel to swell and disperse, causing cracks on its surface. The ozone reacts with a double bond in the silica gel molecule to form a molar ozonide and a peroxide, which in turn regenerates the ozonide. The ozonide decomposes into a radical under the action of light and heat, resulting in a chain growth reaction. In addition, the silicone rubber will generate molecular fracture under the action of stress without generating an ozonized oxide, which may cause cracking and aging.