What Is Redispersible Polymer Powder (RDP)? Redispersible Polymer Powder (RDP) is a free-flowing, white powder made by spray-drying special polymer emulsions. When mixed with water, the powder redisperses back into a stable polymer emulsion, giving it excellent bonding and performance-enhancing properties. RDP is a key additive widely used in dry-mix mortar formulations and various...