1.Selection of dispersion medium
Common dispersing media for oil suspensions:
Why methylated Vegetable Oil ?
1.Features a high flash point, low toxicity, and low volatility, along with strong penetration ability.
2.It has relatively stable quality and lower viscosity compared to soybean oil, making it advantageous for preparing higher loading OD formulations.
3.Compared to petroleum hydrocarbon solvents, it is environmentally friendly, renewable, and easily biodegradable.
4.Common types include soybean oil methyl ester, rapeseed oil methyl ester (from Russia), and palm oil methyl ester (from Southeast Asia)
2.Selection of thickener
Main Types of Thickeners in Oil Suspensions (OD):
Organo Bentonite(SP-OD404)
SP-OD404 is the most common thickener for oil dispersions. It is made from bentonite, utilizing the layered structure of montmorillonite within the bentonite, and produced by inserting an organic covering agent through ion exchange technology.
Organo bentonite can form gels in various organic solvents, offering good thickening properties, thixotropy, and suspension stability.
Silica (Fumed Silica, Precipitated Silica)
Fumed silica is used to thicken and impart thixotropy to non-polar systems. The surface hydroxyl groups on silica can form hydrogen bonds directly or indirectly with each other or with liquid molecules, creating a three-dimensional network structure.
Due to this unique structure and performance, fumed silica demonstrates excellent thickening, thixotropy, anti-settling, and adsorption properties in practical applications.
The spatial structural stability of the thickener is insufficient to meet the suspension requirements of OD formulations. The effectiveness of a single thickener is limited; therefore, combining organo bentonite with fumed silica can achieve a more desirable thickening effect.