Redispersible Polymer Powder (RDP) is a spray-dried polymer powder derived from vinyl-based emulsions (typically VAE/VAE-type or acrylics). When mixed with water, it re-disperses to behave like the original emulsion, forming flexible polymer films that improve adhesion, cohesion, and water resistance in cement-based systems. RDP is a staple ingredient for manufacturers of dry-mix mortars because it brings emulsion performance to a stable, easy-to-store powder form.