Synthesis And Properties Research Of Polycarboxylic Acid Waterproofing Agent

Polycarboxylic acid type waterproofing agent is organic hydrophobic property. The hydrophobicity materials on organic water-repellent admixture have been extensively used in tunnel waterproofing engineering in America, Australia, Japan and West Germany since the end of the 1950s. However, metal soap and Sodium Silicate on waterproofing agent was applied to tunnel waterproofing gradually after the 1980s. The advanced carboxylic acid waterproofing agent became main content of cement liquid water-repellent admixture that Korean most used.This paper designs molecular structure of organic water-repellent admixture. We choose carboxylic acid that possesses amphiphilic molecular structure and sodium carbonate and potassium hydroxide as important raw materials. They carry through soaps turns reaction to synthesize polycarboxylic acid type waterproofing agent. Its molecular structure shows that it acts long carbochain as hydrophobic group and serves carboxyl and hydroxyl group as hydrophilic grouping. The influence of monomer mass ratio, reaction temperature, reaction time, emulsifying agent content and mixing speed on polycarboxylic acid type waterproofing agent were studied in this article. In the end perfect response parameter is determinated: saponification temperature is from 55℃to 60℃, saponification time is from 5 min to 10 min, emulsifying agent content is 0.9%. The main crude materials'mass ratio shows that acid A:acid B:natrium carbonicum calcinatum: potassium hydroxide is 2:3.5:0.62:0.15. The homogeneous characteristics of polycarboxylic acid type waterproofing agent are measured according to GB/T 8077—2000 concrete admixture homogeneous experimental method, The technical characteristics of polycarboxylic acid type waterproofing agent are checked depending on JC474—1999 mortar and concrete waterproofing agent. The result shows that polycarboxylic acid type waterproofing agent is provided with good anti-permeability. The mortar osmotic pressure ratio is highly 500% and its water reducing ratio is only 9%. Concrete mixing with polycarboxylic acid type waterproofing agent holds excellent...