The Modification of Calcium Lignosulfonate and Its Applications in Cementitious Materials

Abstract

An azo calcium lignosulfonate (ACL) is synthesized by the coupling of a diazonium salt made from p‐aminobenzene sulphonic acid and calcium lignosulfonate (CL). The surface activity and foaming ability of ACL are evaluated; also the performances of ACL modified mortars such as fluidity and mechanical strength are investigated. Test results show that ACL has higher surface tension and lower foaming ability compared with CL, the disperse ability of ACL is stronger than that of CL at higher dosage than 0.5%, the flexural and compressive strength of ACL modified mortars are superior to that of CL modified mortars.

Keywords:

• Steric hindrance effect
• surface activity
• foaming ability
• air content
• mechanical strength

Acknowledgments

Project supported by the National Natural Science Foundation of China (Grant 50373017), Young and Middle‐Aged Scientist Foundation of Shandong Province (Grant 02BS051) and Shandong Provincial Education Department (Grant J02C06).