Defoamer for polyurethane is a kind of chemical additive specially designed for polyurethane system, which aims to effectively control and eliminate foam generated during production or application. Its components are diverse, mainly including organosilicon, polyether, mineral oil, and composite defoamers. These components exhibit excellent dispersibility, stability, and defoaming ability through specific chemical structure design. Defoamers usually have low surface tension, which can rapidly penetrate and destroy the foam film to achieve defoaming effect. At the same time, they also need to have good compatibility with polyurethane systems to ensure that they will not have a negative impact on product performance during use.

The action principle of defoamer for polyurethane is mainly based on the following aspects: First, by reducing the surface tension of foam, foam film becomes fragile and easy to break; The second is to destroy the stability of foam membrane and make the foam dissipate rapidly by infiltrating and diffusing to the inside of the foam membrane; The third is to control the generation of foam from the source by inhibiting the generation of foam. These mechanisms work together to enable defoamers to efficiently and stably exert their defoaming effect in polyurethane systems.

Polyurethane, as an important polymer material, is widely used in various fields such as furniture, construction, automobiles, shoe materials, etc. However, during the production process, the mixing, reaction, and processing of polyurethane raw materials are often accompanied by foaming, which not only affects the appearance quality of the product, but may also reduce its physical properties and durability. Therefore, defoamers for polyurethane have emerged as a key additive to ensure the quality of polyurethane products.