Triethanolamine and triisopropanolamine properties
The slag cement has the advantages of low hydration heat, high late strength, inhibition of alkali aggregate reaction, and resistance to sulfate corrosion, and has been applied in a large number of projects. When producing slag cement, due to the poor grindability of slag compared with clinker, the best active particle size is not achieved when co-grinding, and the single grinding will cause a lot of energy consumption, so it is used in the grinding process. Grinding aids to reduce grinding energy consumption and improve cement performance. Triethanolamine (TEA) and Triisopropanolamine (TIPA) are the main components of common grinding aids. They have strong polarity and can reduce the free energy of cement particles, prevent particle agglomeration and increase particles. The specific surface area also accelerates the hydration rate of clinker minerals. Most of the cement grinding aids are alcohol amines and polyols. The alcohol amines mainly include triethanolamine and triisopropanolamine. TEA is a more traditional grinding aid than earlier and more extensive research and application of TIPA. However, due to its high cost and poor performance stability, new grinding aid materials have been developed at home and abroad to replace or partially replace TEA. TIPA is similar in structure to TEA, but in some respects superior to TEA, it uses less blending, lower relative cost, and more stable performance.
Both triethanolamine and triisopropanolamine TIPA can reduce the fineness of slag cement, increase the specific surface area, increase the content of fine particles, and increase the water demand of cement, but have little effect on the setting time. Triethanolamine and triisopropanolamine TIPA have a significant effect on the strength of slag cement. The strength of slag cement increases with the addition of grinding aid. The compressive strength of cement with 0.05% TIPA increases by 28 d. 5.58 MPa. Triisopropanolamine TIPA is superior to triethanolamine in enhancing the slag cement. Under the action of triethanolamine and triisopropanolamine, the hydration rate of the slag cement is accelerated, the type of hydration product is unchanged, but the amount is increased, the crystallinity is better, and the hydration products are cross-linked, thereby forming a more Dense structure.