Views: 21 Author: su Publish Time: 2018-11-16 Origin: Site
TIPA is a rectification separation of ammonia and propylene oxide after addition reaction. Triisopropanolamine can be widely used in daily chemical, fine chemical, petrochemical, etc., and is an important amine compound. TIPA is the core material for cement grinding aids, and triisopropanolamine is also an organic reinforcing agent for cement concrete. As a cement grinding aid and concrete early strength agent, TIPA is generally considered to significantly increase the 28-day compressive strength of cement mortar.
The TIPA structure contains both a hydroxyalkyl group and an amine group, and the charge centers do not coincide. The amine nitrogen atom is simultaneously connected to the three hydroxyalkyl groups, and the pair of lone pairs on the nitrogen atom are bare. It has strong electronegativity, and has a large steric hindrance with powder adsorption, while hydroxyalkyl groups can adsorb on the surface of cement particles; the electronegativity of nitrogen makes it electrostatically repulsive, and the newly generated surface after particle breakage The bond breaks with different charges, and the two can be combined to avoid re-aggregation of the new surface, reduce the surface energy of the particles, reduce the viscosity of the particles, and improve the fluidity. Due to the long hydroxypropyl carbon chain of TIPA, the steric hindrance after adsorption of particles is larger, so its fluidity is stronger, which shows that the angle of repose is more reduced.
TIPA accelerates the dissolution of cement clinker minerals, promotes the dissolution of minerals in aqueous solutions, and promotes the dissolution of mineral solid solutions under anhydrous conditions, especially the dissolution of mesophase solid solutions. This trend is enhanced as the temperature and dosage increase. The main effect of TIPA on cement hydration is to accelerate the dissolution of C4AF and form a complex with the iron hydroxide gel formed by C4AF hydration, preventing the iron hydroxide gel from precipitating on the C4AF surface under high pH conditions, thereby accelerating the iron phase. Hydration.
TIPA is an excellent grinding aid and enhancer that improves the fluidity of cement and improves the hardening strength of cement by promoting the dissolution and hydration of solid solution, especially iron phase solid solution. Triisopropanolamine has excellent grinding properties. TIPA has a polar group and a spatial three-dimensional structure, which can narrow the particle size distribution of cement particles and improve the fluidity of cement. TIPA has the property of improving the hardening strength of cement. TIPA can significantly increase the hardening strength of cement up to 15%, but not exceeding the maximum amount, otherwise it will lead to abnormal condensation. TIPA has the effect of promoting cement hydration.
TIPA promotes the early hydration of cement by promoting the dissolution of mesophase, and promotes the strengthening of temperature and dosage. TIPA is more conducive to the dissolution and hydration of C4AF, which can accelerate the reaction of mesophase hydration to form Afm after gypsum depletion.