Antifreeze

 General Properties:  Low molecular weight, highly water-soluble polyols (e.g., propylene glycol, ethylene glycol) or urea; low volatility and high thermal stability.

 Synergistic Role in Defoamers: When a water-based defoamer freezes, the expanding ice crystals physically rupture the emulsifier film surrounding the oil droplets. Upon thawing, the oil and water permanently separate (irreversible demulsification). Antifreeze prevents ice crystal formation, protecting the emulsion structure.

 Performance Benefits:

Freezing Point Depression: Lowers the freezing point of the defoamer, allowing it to remain liquid in sub-zero temperatures.

Ensures Freeze-Thaw Stability: Protects the emulsifier film from ice-crystal damage, ensuring the defoamer regains its full performance even after being exposed to cold and then warmed up.