Reversing Adhesive Syneresis

Q: One of the materials I’m using has exhibited syneresis. What is the best way to reverse this process?

A: A few thickened adhesives (in the case of Dymax products, VT and GEL grades) occasionally exhibit syneresis. Syneresis appears as a thin film or puddles of low-viscosity adhesive on top of the thicker adhesive. Sour cream and yogurt are familiar products that also exhibit syneresis. The composition of the low-viscosity-syneresis liquid is chemically identical to the thickened material. It has the same chemical and bonding properties, but the viscosity is much lower.

Time and colder temperatures can promote syneresis. We would recommend using a First In, First Out (FIFO) inventory control. FIFO inventory control can help control the amount of time a product is stored before use. We would also suggest that syneresis-prone materials are not refrigerated. In fact, mild heating can reverse the syneresis in some products.

Once syneresis has occurred, mixing is the most common method of returning the mixture to a homogeneous state. Mixing can be accomplished with a traditional paddle or spatula (being careful to minimize air entrapment) or mixing can be accomplished through the use of a static mixer.

If you have additional questions or need more guidance on this issue contact our Application Engineering Team.