Comparison Between Common Coupling Agents and Titanate Coupling Agents
The following are the coupling agents commonly seen on the market today: 1. Silane coupling agents; 2. Titanate coupling agents; 3. Aluminate coupling agents; 4. Zirconate coupling agents; 5. Aluminium–titanium composite series; 6. Other series (borate type, aluminium–zirconium composite type, etc.).
1. Comparison Between Silane and Titanate Coupling Agents
Silane coupling agents are effective only on fillers containing silicon, whereas titanate coupling agents are suitable for a wide variety of fillers and also for a broader range of resins. Moreover, their effect is not limited to increasing the strength of the composite; they also impart a certain degree of flexibility.
2. Comparison Among Titanate, Zirconate and Aluminate Coupling Agents
Aluminium has greater reactivity than titanium and zirconium. Because highly active species generally react even during storage, aluminates have a shorter shelf life. Zirconate coupling agents have greater heat resistance than titanate and aluminate coupling agents.
Based on the comparisons above, and the fact that titanate coupling agents are the most widely used in both domestic and international markets — with the broadest sales coverage and the largest sales volume — their main characteristics are as follows:
1. Wide range of applications (plastics, rubber, coatings, inks, magnetic materials, pigments and fillers);
2. Wide variety of products (Kenrich Petroleum Company of the USA alone has published nearly 60 grades, and there are currently dozens of grades in China);
3. Storage stability (for example, water-soluble grades can be stored for several years);
4. Reasonable price (definitely lower than silanes, slightly higher than aluminates).
