Study On Novel Polycarboxylic Series Of High Performance Water Reducer

Development of the polycarboxlic acid water-reducer was a modern frontierresearch project. It was characteristic of row additive, higher fluidity effect, andpreventing concrete mix from slump-loss with duration. The domestic research of itwas at first step now. In this dissertation, a series of macro-molecules monomer ofpolyethylene glycol single armor ether methylacrylic acid esters and polycarboxylicwater-reducer had been developed and tested for properties.On the basis of the key group theory, the chemical configuration, workingprinciple of high performance water-reducer and the "purpose building" approach, acomb-like polymer structure of polycarboxylic acid water-reducer with carboxylicgroups, sulphonic groups and polyoxyethylene side chain groups was synthesizedthrough esterify and polymerization by the materials of Methylacrylic acid,polyethylene glycol single armor ether and 2-acrylamido-2-methlpropanesufonic acid.After a series of orthogonal and signal tests were performed individually, the crucialfactors in the performances and optimum processing parameters have been attained,and dynamics analysis was performed.Through the study of IR spectrum and chemical test, it was proved thatpolycarboxlic acid water-reducer can be synthesized in the aqueous system by tri-polymerization of vinyl monomers with carboxylic groups, sulphonic groups andpolyoxyethylene side chain groups. Through the studying of surface properties suchas surface tension, inherent viscosity, esterification productivity and so on, discussedthe water reducing mechanism.Making a comparion between as-synthesized polycarboxlic acid water-reducerand other ones according to the correlative standard rules, the products possess somesuperior characteristics, such as the high dispensing property, long keeping time offluidity, good compatibility with various cements and good adhesiveness of cementand so on. Comparing with the naphthalene type high water-reducer, it had betterdispersion effect and the same properties as this kind of products overseas.