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Surface properties of unsaturated polyester resin

Feb 23, 2019

When the unsaturated polyester resin is cured, it is difficult to cure due to the inhibition of oxygen in the air, resulting in stickiness. As a result, it is limited in many applications, for example, it cannot be used as a coating. In order to change the embarrassing condition in the early stage, it is common to add paraffin wax to the resin. When curing, the paraffin wax forms a film to block oxygen, which is beneficial to solidify the surface of the resin. But one is that the tree Buddha becomes opaque, and the other is that this layer of wax wax hinders the adhesion of the latter resin to the front resin layer. Subsequent studies have found that the use of the following alcohols in the condensation polymerization can overcome the problem of surface stickiness. It is believed that these alcohols contain allyl ether groups, which easily oxidize the dilute propyl ether when exposed to air. This oxidized group decomposes free radicals when it encounters a cobalt salt promoter. The surface is accelerated to cure, so it is also called air-drying unsaturated polyester resin. Unfortunately, this alcohol is relatively expensive, and it is easy to cause cross-linking when it participates in condensation polymerization, so it has not been widely promoted. At present, the relatively new technology uses a highly dispersible silicone surfactant, which is used in a very small amount, but has a strong barrier to oxygen. Although the price is very expensive, the application is quite common due to the small amount of use.

  Through the above-mentioned crosslinked network structure of unsaturated polyester resin and its mobility, analysis method, prepolymer molecular weight, crosslinking agent, initiator, curing conditions, etc., on the properties of unsaturated polyester resin, and in the presence of poly The microphase separation phenomenon in the network structure of ester resin, the discussion of the relationship between molecular structure and properties, and the contribution of some special link structures to the performance and molecular design are also introduced, so as to relate the structure and properties of unsaturated polyester resin. There is a good understanding and understanding. It is said that "we can only feel it more deeply if we understand something", so even though I have introduced a lot of content in this chapter, if you really feel that it knows it, you have to go to practice and explore and develop them. The application makes it more humane.