Is acrylic sealant vulnerable to cold storage?

Is acrylic sealant vulnerable to cold storage?

Acrylic sealant is particularly sensitive to cold temperatures. Low temperatures can significantly affect its performance stability and subsequent performance. The specific reasons and storage requirements are as follows:

The Core Impact of Low Temperature on Acrylic Sealant
The main components of acrylic sealant (such as acrylate monomers, initiators, plasticizers, and fillers) are temperature-sensitive. Low temperatures can damage their quality through both physical and chemical reactions:

Physical Changes: The colloid becomes hard and difficult to apply.
Low temperatures reduce the fluidity of the plasticizer in the colloid and slow the molecular motion of the base material, causing the originally paste/liquid sealant to gradually harden, become brittle, and even form lumps. During subsequent application, it becomes difficult to squeeze out of the hose and, after application, it will not adhere evenly to the substrate, directly affecting the sealant’s performance. Curing Reaction Inhibition: Slower Curing or “False Curing”
Acrylic sealants rely on free radical polymerization (especially one-component acrylic sealants, which require absorption of moisture or oxygen from the air to trigger the reaction). Low temperatures inhibit the activity of the initiator, slowing the generation of free radicals.

Mildly low temperatures (e.g., 0-5°C): Curing time is significantly prolonged (e.g., a 24-hour cure at room temperature may take over 72 hours at low temperatures).

Severely low temperatures (e.g., below 0°C): “False Curing” may occur—the surface of the sealant appears dry, but the interior is not fully cured. This can lead to cracking and flakes, preventing the sealant from forming an effective seal.

Prolonged Low Temperatures: Separation of Components and Performance Loss

Extended exposure to temperatures below 0°C (e.g., more than a month) can cause separation between fillers (e.g., calcium carbonate, talc) and the binder due to density differences, resulting in a “thin top layer and thick bottom layer” or precipitation. Even with subsequent warming and stirring, it is difficult to restore uniformity, ultimately leading to a significant decrease in bond strength and tensile properties.