When the unsaturated polyester resin is cured, due to the polymerization inhibition of oxygen in the air, the surface is difficult to cure and causes stickiness. As a result, its use is restricted in many occasions, for example, it cannot be used as a coating. In order to change this embarrassing situation in the early days, paraffin wax was often added to the resin. When curing, the paraffin wax was formed into a film to isolate oxygen, which was conducive to curing the resin surface. But first, the tree Buddha became opaque, and second, this layer of wax wax hindered the adhesion of the back resin to the front resin layer. Later research found that the following alcohols can be used in condensation polymerization to overcome the problem of surface stickiness. There is a view that these alcohols contain allyl ether groups, and they easily oxidize the dilute propyl ether when they encounter air. This oxidized group decomposes out free radicals when it encounters a cobalt salt accelerator, which promotes The surface is accelerated curing, 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 participating in condensation polymerization, so it has not been widely promoted. At present, the relatively new technology is the use of highly dispersible silicone surfactants, the dosage is very small, but the performance of oxygen barrier is very strong. Although the price is very expensive, the application is still quite common due to the small amount.
After the above-mentioned effects on the unsaturated polyester resin cross-linking network structure and its mobility, analysis methods, prepolymer molecular weight, cross-linking agent, initiator, curing conditions, etc., the performance of the unsaturated polyester resin, as well as the presence in the polymer The micro-phase separation phenomenon in the ester resin network structure, the discussion of the relationship between molecular structure and performance, and the contribution of some special link structures to the performance and molecular design are also introduced, so that the relationship between the structure and performance of the unsaturated polyester resin There can be an understanding and understanding. There is a saying, "Only what we understand can we feel it more deeply", so although a lot of content is introduced in this chapter, but to really feel it deeply understand it must also go to practice, to dig and develop them Application to make it better for human beings.