Choice of Coagulant for Maximum Transaprency in Latex Dipped Products

Manufacturer: With your help, we have managed to modify our latex compound formulations to achieve transparency of our latex dipped products with some success. However, we were informed that the choice of the types of coagulant is also important. We found straight dipping gave the best result but once we used calcium nitrate or calcium chloride, the unwanted opacity increases. Can you please explain?


John Woon (Senior Latex Consultant): I had explained about the choice of coagulant for maximum transparency in latex dipped products earlier in this blog.

The reason why you could not get good transparency when using calcium nitrate or chloride is that the resultant calcium soaps after coagulation are not soluble in the rubber. Also, the calcium soaps are not soluble in water and hence leaching would not help in improving the transparency significantly.

The best coagulant to be used for maximum transparency is CHA i.e. Cyclohexylamine Acetate (or Cyclohexylammonium Acetate). This is because while the cyclohexylamine itself is volatile, the resultant cyclohexylamine soaps are soluble in rubber.

One disadvantage of CHA is that it is a weaker coagulant compared to the calcium salts.

I'm happy to note that my report on latex compound formulation design for transparency had been useful to you.