In latex paints, coalescing aids reduce the glass transition temperature (Tg) allowing the polymers to flow together and form a film. Since coalescing aids are volatile, they evaporate out of the film thus allowing the polymer to return to the original Tg.
A coalescing aid must fulfill three criteria:
- Be compatible with base polymer of the system.
- Lower the minimum film-formation temperature (MFFT).
- Evaporate at a lower rate than water.
xF Technologies offers a range of solvents that can function as efficient coalescing aids and two examples are triethylene 408 (TEG 408) and methoxyethyl 408 (ME 408).