Surface modification of wollastonite and its application in natural rubber

07/12/2022
|In Industry News
|By ALPA

Wollastonite is a fibrous cleaved metasilicate mineral, which has a series of excellent properties such as needle-like structure, high whiteness, low thermal expansion coefficient, excellent chemical stability and flame retardancy, and high electrical insulation. Physical and chemical properties, so wollastonite has broad application prospects.

With the development of wollastonite deep processing technology research, wollastonite has gradually become a high-quality raw material in many industrial fields such as polymer rubber and plastic industry, paint and coating industry, building material industry, ceramic metallurgy industry, and paper industry.

Using a certain wollastonite as raw material, using dodecylamine and Si-69 to carry out surface modification and filling application tests on wollastonite, discuss the process conditions of dry modification of wollastonite and the effect of modifying agents on the surface of wollastonite. mode of action, and using natural rubber as the matrix to explore the application effect of modified wollastonite, the results show that:

(1) Si-69 coupling agent can form chemical adsorption on the surface of wollastonite. The optimal conditions for modifying wollastonite are: dosage of 0.5%, modification time 60min, modification temperature 90°C. Under these conditions, the activation index of the modified wollastonite is 99.6%, and the contact angle is 110.5°.

(2) Dodecylamine exists in the form of physical adsorption such as hydrogen bond adsorption on the surface of wollastonite. The optimal conditions for modifying wollastonite are: dosage of 0.25%, modification time of 10 minutes, and modification temperature of 30°C. Under these conditions, the activation index of modified wollastonite is 85.6%, and the contact angle is 61.5°.

(3) The improvement effect of modified wollastonite on the mechanical properties of natural rubber is better than that of unmodified wollastonite, and the improvement effect of Si-69 coupling agent and dodecylamine mixed modified wollastonite on the mechanical properties of natural rubber is even greater. good.