Hi everyone. I synthesize water-based polyurethane. I didn't have a problem until a few months ago, but with the start of summer and the temperature getting warmer, I started having problems. I don't know if warming the air is effective or not. When I add water to the system, the system becomes like white glue and the water is completely separated from it, in other words, it becomes two phases. Is this substance similar to white glue due to the reaction of isocyanate with water? Or TEA failed to neutralize? Is it possible that TEA has expired due to ambient heat?
When you added water to waterborne polyurethane, it makes an emulsion. your emulsion is not stable due to the inappropriate hydrophilic to hydrophobic ratio and change of pH. I suggest first you check the pH of your product/reaction mixture and add any emulsifying agents with an appropriate HLB value.
Mix TEA in PU synthesized as per the moles calculated and mix for 10-15 minutes. While preparing emulsion do reverse addition. PU [separating flask] dropwise slowly in water under high speed stirring. You will have exothermic reaction.
- Badges
- Science topic
- Similar topics
- Computer Science
- Research Topics