Title: Synthesis of a Novel Superplasticizer Prepared from Brown Coal

Author(s): Manuel Ilg and Johann Plank

Publication: Symposium Paper

Volume: 302

Issue:

Appears on pages(s): 63-76

Keywords: admixture; adsorbed layer thickness; brown coal; graft copolymer; lignite; superplasticizer

DOI: 10.14359/51688085

Date: 6/1/2015

Abstract:
Polycondensates and polycarboxylates are known to be effective superplasticizers. Here, the synthesis of a novel, brown coal based superplasticizer by grafting acrylic acid (AA) and 2-acrylamido-2-tert.butyl sulfonic acid (ATBS) onto the alkali soluble components of brown coal (lignite) as backbone using free radical copolymerization technique is described. Furthermore, an ATBS-acrylic acid copolymer was synthesized to investigate the influence of the graft chains on the performance of the lignite copolymer. Successful grafting was confirmed by size exclusion chromatography (SEC) and comparison of the adsorbed layer thicknesses of the brown coal substrate and the grafted product. The dispersing performance of the graft copolymer was probed via mini slump tests and compared with that of BNS. Additionally, slump flow retention and sulfate tolerance were determined. It was found that the graft copolymer possesses higher dispersion effectiveness than BNS and exhibits high sulfate tolerance.