This polymer cement is composed of polyester resin, ordinary portland cement and a catalyst that generates free radicals. This catalyst is insoluble in polyester resin, but easily soluble in water. Its curing is carried out by adding water [add water 8% (Quality Score)).
The catalyst can be ammonium persulfate. The cement is treated with hydrophobic stearic acid and is easily dispersed in the resin. When water is added to the polyester cement, the catalyst first dissolves. The water and cement react to form calcium hydroxide. This in turn causes the catalyst Free radicals generate free radicals. Free radicals initiate polyaddition reaction between styrene and polyester resin. The whole process gradually turns liquid cement into solid state while slowly exothermic. Most of the shrinkage stress generated is released by plastic flow. Ester cement and ordinary concrete can be firmly bonded.
A small amount of modified additives can be added to polyester cement, including finely ground dicarboxylic acid. This can neutralize the free lime produced by the reaction of water and cement in the resin, thereby extending the shelf life. Other additives can also be used to reduce the cement in It is deposited in storage and helps to disperse. The basic formula and typical properties of polyester cement are shown in Table 7-1.
After the polymer cement is mixed with aggregates and sand, the compressive strength after 24 hours of curing is equivalent to the compressive strength of ordinary portland cement after 28 days, and the chemical resistance is better than that of ordinary concrete and general polymer cement. Polyester cement can be used for corrosiveness The floor of the chemical workshop can also be used for road surfaces, especially bridge surfaces and other places that require rapid hardening of the surface to facilitate repair.