1. Redispersibility: Redispersible latex powder with good redispersibility can dissolve in water and form a stable emulsion similar to the original emulsion. Poorly redispersible powders cannot be uniformly modified and may contain non-redispersible polymers.

2. Film-forming property: The film-forming property is the basis for modifying adhesives and mortars. Poor film-forming properties are usually due to excessive addition of inorganic components or improper organic components. High-quality redispersible latex powder has good film-forming properties at room temperature. If it does not form a film well at room temperature, it often indicates issues with the polymer or ash quality.

3. Water resistance of the film: Redispersible latex powder that forms good films also has excellent water resistance. Powders with poor water resistance generally contain more water-soluble polymers.

Based on application standards:

1. Dry bond strength and water-resistant bond strength: Poor bonding indicates issues with polymer or ash quality.

2. Flexibility and impact resistance: Poor flexibility indicates issues with polymer quality. Decreased flexibility during use might be due to the presence of plasticizers.

3. Hydrophobicity and non-hydrophobicity: Good surface hydrophobicity can reduce the workability and bond strength of mortar.

4. Flow and rheology: Poor rheology indicates issues with polymer or additives quality.

5. Foaming and defoaming properties: Abnormal foam behavior indicates issues with polymer, ash, or additive quality.

Testing methods:

1. Visual method: Use a glass rod to thinly and evenly cover a small amount of redispersible latex powder on a clean glass plate, place the glass plate on white paper, and visually inspect the appearance of particles, foreign objects, and coagulates.

2. Solubility test: Take a small amount of redispersible latex powder and put it into five times its volume of water, stir, and then observe after 5 minutes. In principle, the less insoluble material settling at the bottom, the better the quality of the redispersible latex powder.

3. Ash content method: Weigh a certain amount of redispersible latex powder, place it in a metal container, heat it to about 600 degrees, burn it at high temperature for about 30 minutes, cool it to room temperature, and weigh it again. Lighter weight indicates better quality.

4. Film-forming method: Take a certain amount of redispersible latex powder, put it into twice its volume of water, stir evenly, let it sit for 2 minutes, stir again, pour the solution onto a flat glass, and place the glass in a well-ventilated shaded area. After drying, observe that higher transparency indicates better quality.