Study on polyether modified organosilicon defoamer


There are many kinds of defoamers, and the classification is also full of diversity. As we discussed before, according to the principle of action, it can be divided into three types: antifoaming agent, defoamer and defoamer; according to the effective components of defoamer, it can be divided into organosilicon defoamer, polymer defoamer and mineral oil defoamer.


Polyether defoamer is a kind of defoamer widely used in recent years, and its defoaming property is good. The advantages of polyether defoamers are that they are nontoxic and convenient to use. The most important thing is that they have good antifoam performance, dispersibility, thermal stability and chemical stability, which ensure the stability of defoamers. The biggest drawback of such defoamer is the low efficiency of bubble breaking. That is to say, when the foam has been generated in the system, it is very difficult for polyether defoamer to remove the foam quickly. It also tells us that polyether defoamer should be added at the initial stage of the paint process, which can effectively inhibit the foam generation and give full play to the excellent antifoaming property of the defoamer. Organosilicon defoamer has the advantages of strong defoaming, low temperature requirement for the use environment, stable physical and chemical properties, and physiological inertia, which will not bring harm to human body. It can be used in both water-based coating system and non-water-based coating system. The disadvantage of organosilicon defoamer is that its preparation process is complex. If the control is not good, the defoamer effect will be affected. The defect of surface shrinkage due to its low surface tension.


Although polyether defoamers and organosilicon defoamers have good performance, there are still some shortcomings. In order to learn from each other's strengths and make the best of their defoamers, they are combined to get the silicone ether mixed defoamers. The polyether modified polysiloxane defoamer prepared by grafting method not only has the advantages of good defoamer performance and low surface tension, but also has the advantages of high temperature resistance and strong antifoam resistance.


Through the application data, the advantages of polyether modified silicone defoamer in terms of antifoam performance are shown, the compatibility of silicone defoamer is improved, and the surface defects, such as shrinkage cavity, are reduced.