The difference between silicone vulcanization and non vulcanization

Silicone, as an important polymer material, is widely used in many fields such as medical devices, electronic components, and building materials. In the production and application process of silicone, vulcanization is a crucial step. The vulcanization or not directly affects the physical properties, chemical stability, and thermal conductivity of silicone. This article aims to explore in depth the differences between silicone vulcanization and non vulcanization, providing valuable references for the application and research and development of silicone.
Firstly, let’s understand the basic concept of silicone vulcanization. Silicone vulcanization refers to the introduction of active bonds such as double and triple bonds into silicone molecules, followed by the addition of auxiliary and crosslinking agents. Through heating or pressure, the active bonds in silicone molecules undergo ring opening reactions, forming a three-dimensional spatial network structure. The vulcanized silica gel has excellent properties such as high strength, high wear resistance, high aging resistance, and also has the characteristics of heat resistance, cold resistance, acid and alkali resistance, water resistance, moisture resistance, and so on.
On the other hand, non vulcanized silicone does not undergo the aforementioned vulcanization process. This type of silicone typically exhibits lower strength and wear resistance, while lacking the high-temperature stability and chemical stability that vulcanized silicone possesses. Unsulfided silicone may exhibit good elasticity and softness in certain applications, but due to its relatively weak performance, it is usually only suitable for areas with low performance requirements.
Next, we will elaborate in detail on the differences between silicone vulcanization and non vulcanization from three aspects: physical properties, chemical stability, and thermal conductivity.

Silicone vulcanization improves physical properties, chemical stability and thermal conductivity, suitable for high demand areas;

In terms of physical properties, the strength and wear resistance of vulcanized silicone are significantly better than those of non vulcanized silicone. The cross-linking structure formed during the vulcanization process makes the molecular connections between silicone gel more tightly, thereby improving its physical properties. In addition, vulcanized silicone also has good elastic modulus and rheological properties, which can be adjusted according to different degrees of vulcanization to meet the needs of different application scenarios.
In terms of chemical stability, vulcanized silica gel also performs well. The molecular structure of vulcanized silicone is more stable and can effectively resist the erosion of harsh environments such as acid, alkali, and oil. However, due to the lack of cross-linking structure protection, non vulcanized silicone has relatively poor chemical stability and is easily affected by external environmental factors, leading to deterioration.
In terms of thermal conductivity, vulcanized silicone is also superior to non vulcanized silicone. The cross-linked structure formed during the vulcanization process increases the contact points between silicone molecules, thereby improving their thermal conductivity. This makes vulcanized silicone have better heat dissipation effects when applied in electronic product radiators, thermal pads, and other fields.
In addition to the aforementioned performance differences, there are also significant differences in the application fields between silicone vulcanization and non vulcanization. Vulcanized silicone is widely used in high demand sealing rings, rubber pipes, high-temperature resistant parts, and other fields due to its excellent physical properties, chemical stability, and thermal conductivity. Non vulcanized silicone is more commonly used in situations where performance requirements are not high, such as sealing gaskets, soft molds, etc.