Precipitated silica has a significant reinforcing effect in polymer composites, which is mainly reflected in the following aspects:

Strength and hardness enhancement: Precipitated silica is added to the polymer matrix as a filler, which can effectively increase the strength and hardness of the composite material. The high specific surface area and surface activity of silica provide more reinforcing interfaces to form effective interactions with the polymer matrix, thereby improving the mechanical properties of the composite.

Improved thermal stability: Silica has excellent thermal stability, and its addition can improve the heat resistance and thermal stability of polymer composites. Under high temperature conditions, silica can be stably dispersed in the polymer matrix and prevent the thermal decomposition and degradation of polymer molecules.

Dimensional stability: Due to the small and uniform particle size of precipitated silica, its addition can effectively prevent the dimensional change and expansion of the polymer composite. This is especially important for engineering and manufacturing applications that require high precision and dimensional stability.

Improvement of conductivity: Precipitated silica has certain conductivity, and its addition can endow the polymer composite with certain conductivity. This makes the composite material have important applications in the fields of electronic devices, electrostatic dissipation and so on.

Anti-ultraviolet performance: The surface structure and chemical properties of silica make it have good anti-ultraviolet performance. Adding white carbon black can effectively enhance the anti-ultraviolet aging ability of polymer composites and prolong the service life.

Low-density reinforcement: Although silica itself has a high specific surface area, its density is low, so adding an appropriate amount of silica will not significantly increase the density of the composite material while achieving the reinforcement effect.

It should be noted that the reinforcing effect of precipitated silica is affected by factors such as its addition amount, dispersibility and compatibility with the polymer matrix. Excessive addition and poor dispersion may lead to a decrease in the mechanical properties of the composite. Therefore, in practical applications, it is necessary to comprehensively consider the properties of silica and the addition conditions to obtain the best reinforcement effect.

In general, precipitated silica as a filler shows a good reinforcing effect in polymer composites, making composites widely used in many fields, such as auto parts, electronic devices, building materials, etc.