Is normally provided by unsaturated dicarboxylic acid or unsaturated dibasic acid diols of unsaturated diols condensation that has formed ester bond and unsaturated double bonds of the linear polymers. Typically, the polyester-based condensation reaction is carried out at 190 ~ 220 ℃ until it reaches the desired acid value (or viscosity), in the reaction of polyester-based contraction after the end of still hot by adding a certain amount of vinyl monomer, dubbed sticky thick liquid, such a polymer solution is called unsaturated polyester resins.
Chemical raw materials, commonly used in surface thickening, curing, when used as a general paint, layer upon layer stack increases, the curing process the release of styrene and other harmful gases.
Unsaturated polyester resin is a thermosetting resin, the most common one, which is a saturated dicarboxylic acid, unsaturated dicarboxylic acids and diols formed linear condensation polymers, through cross-linking monomer or the formation of active solvent diluted that has a certain viscosity of the resin solution, referred to as UP.
Unsaturated polyester resin performance characteristics:
1. Craft excellent performance. This is not the greatest advantages of unsaturated polyester resins. Can be cured at room temperature, and pressure forming, process performance, flexibility, particularly suitable for large-scale and on-site manufacture of glass fiber reinforced plastic products.
2. Cured resin, a good comprehensive performance. Slightly lower than the mechanical properties of epoxy resin, but better than the phenolic resin. Corrosion resistance, electrical properties and flame resistance can be by selecting the appropriate grade to meet the requirements of resin, resin color of light, can be made into transparent products.
3. Varieties to meet the wide range of lower prices.
4. Drawback is that the curing shrinkage of larger storage period is short, including styrene, irritant gas, the adverse long-term exposure on health.
