Research On The Synthesis Of Modified Alcohol And Its Effect On Cement Performance

Adding the right dosage of grinding aids in Cement production can effectively improve the grinding efficiency,improve the performance of cement,and it is an effective way of saving energy and reducing emission.Alcohol amines grinding aids are currently used in a wider range.It enhanced grinding effect better.However,there are shortcomings such as high price,low universality and poor performance.In this paper,new modified alcohol amines are developed by the modification of ethanol amines,in order to improve the shortcomings of alcohol amine grinding aids.In this paper,triethanolamine and triisopropanolamine were modified and six modified alkanolamines,such as maleic acid triisopropanolamine ester?MI?,acetic acid triisopropanolamine?HI?,maleic acid triethanolamine ester?MT?,acetic acid triethanolamine salt?HT?,polymer of modified amine PMT and polymer of modified amine AMT,were synthesized.The optimum synthesis process of MT was obtained.The effect of the modification of ethanol amines on cement properties was studied,through physical properties and particle distribution.Microscopic means such as FTIR,XRD,SEM and TG-DSC were used to study the effect of the modification on the enhanced grinding effect and its mechanism.The results are as follows:1.The best synthetic process conditions of MT are:the temperature is 115?,the reaction time is 4h,n?MA?:n?TEA?=1.5:1;the FTIR test results show that maleic anhydride and alcohol amine connected through the ester in the molecular structure of MT.2.The optimal content of TIPA,MI and HI is 0.02%.TIPA can not improve 3d compressive strength of cement pastes,the 28d compressive strength increased by14.4%.The 3d and 28d compressive strength of cement pastes with MI and HI increased by 8.9%,9.9%and 22.2%,17.8%,respectively.The content of chemical combined water of cement pastes with MI and HI is higher than blank,and the results show that the hydration process of cement is improved,which is consistent with the compressive strength.XRD and SEM analysis shows that the AFt diffraction peaks of TIPA and MI cement pastes are sharp in early stage,it indicates that TIPA and MI acclerate the hydration of C₃A in early stage,and TIPA inhibited the early hydration of C₃S,MI and HI promoted the early Hydration of C₃S,and more hydration products are produced in late stage,and the structure of cement is more dense.The Grinding experimental results show that MI and HI have a good grinding effect.3.The best dosage of TEA,MT,HT,PMT and AMT was 0.02%,0.02%,0.01%,0.02%and 0.02%respectively.The 3d and 28d compressive strength of cement pastes with MT,HT and PMI increased by 9.6%,3.9%?13%and 6.2%,5.7%,9.0%,respectively,and they effectively improved the disadvantage of TEA.The compressive strength of cement pastes with AMT was lower than that of blank.The microscopic test results show that the AFt and C-S-H gels in cement hydration products with HT,MT and PMT are higher than those of the blanks,and the polymerization degree of[SiO₄]^4-is improved,and the cement structure is more compact,porosity decreased,the development of cement strength more favorable.4.Under the content of 0.02%,the grinding effect of MT,PMT and AMT is significant,the range of 3³2?m increased and the surface of the powder particles was rough and the particles became more round.AMT has significant effects on sieved particles of 45?m and 80?m and specific surface area,respectively,sieved particles of 45?m and 80?m reduce 30%and 32.5%,the specific surface area increase12.7%.PMT is better grinding and optimization of grain size distribution,with the highest content of 3³2?m particles.TEA,PMT,and PMT have shortened the initial setting time and final setting time of cement,and PMT has the most significant effect on cement initial setting and final setting time,which are accelerated by 14.4%and 21.6%,respectively;AMT has a certain degree of extension to the initial setting and final setting of cement.