Synthesis and evaluation of starch-based polymers as potential dispersants in cement pastes and self leveling compounds

摘要

In order to make concrete construction greener, new High Range Water Reducing Admixtures (HRWRAs) from natural origin-should be developed. Some natural polysaccharides and their derivates have interesting properties which explain their growing use in the field of materials. Their use is not only linked to the biodegradable and atoxic aspect but is also linked to the fact that they can confer new properties to cement-based materials. In the presented study, starch has been chosen as main polysaccharide chain. Starch has first been used without any modification, and then with different grafted substituents like acetate, maleate, succinate, sulfonate to mimic the structure of petrochemical HRWRAs. Some tests have been done to evaluate the potential effect of these biobased derivatives as new HRWRAs. Some of the starch-based polymers were also evaluated in a commercial self-leveling compound. Results show that a graft of sulfopropyle or sulfobutyle side chains on a starch polymer can lead to slump flows on grouts comparable with the ones obtained on PolyNaphtalene Sulfonate (PNS) based grouts, and also that starch-sulfobutyle or starch-maleate can potentially replace casein in self-leveling compounds.