|
Title |
The Dispersibility and Adsorption Behaviour of Cement Paste with Molecular Structures of Polycarboxylates
|
|
Authors |
신진용 ; 홍지숙 ; 서정권 ; 이영성 ; 황의환 |
|
Keywords |
폴리카복실레이트 ; 분자량 ; 흡착량 ; 유동성 |
|
Abstract |
Graft copolymerized polycarboxylate(PC)-type superplasticizers which have carboxylic acid with π bond among the molecular structure and polyethyleneglycol methyl ether methacrylate(PMEM) were synthesized by free radical reaction. To investigate their chemical structures and molecular weights, PCs were analyzed by FT-IR(fourier transform spectrometer), C-NMR(nuclear magnetic resonance spectrometer) and GPC(gel permeation chromatograpy). When types of carboxylic acids(methacrylic acid, acrylic acid, maleic anhydride, and itaconic acid) and molar ratios of carboxylic acid/PMEM) were varied, adsorptive and fluid characteristics in cement paste were discussed. As the molar ratio of carboxylic acid/PMEM) was higher, amount adsorbed on the cement particles and the fluidity of cement paste by mini-slump spread testing method were increased. When main chain of PC was methacrylic acid, a larger amount was adsorbed on the cement particles. PCs with acrylic acid as main chain showed higher dispersing power. However, it was confirmed that PCs with dicarboxylic acids(maleic anhydride, itaconic acid) didn't have good adsorption and dispersibility.
|