Effect of chitosan ethers on fresh state properties of lime mortars

3rd International Conference on Innovative Materials, Structures and Technologies

Vyvail, M.^1 ; ilavský, T.^1

Faculty of Civil Engineering, Brno University of Technology, Veveí 331/95, Brno

602 00, Czech Republic^1

关键词: Carboxymethyl chitosan;    Consistency coefficient;    Enhancing effect;    New applications;    Relative density measurement;    Rheological parameter;    Viscoelastic properties;    Water retention ability;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/251/1/012039/pdf
DOI  :  10.1088/1757-899X/251/1/012039

来源: IOP

【 摘 要 】

The fresh state properties of mortars are eminently important since determine the material workability and also have a great influence on its hardened state characteristics. In this paper, the behaviour of fresh lime mortars modified by etherified derivatives of chitosan (hydroxypropylchitosan (HPCH) and carboxymethylchitosan (CMCH)) is assessed with the purpose of exploring a new application of such derivatives as lime mortar admixtures. The rheological parameters (relative yield stress, consistency coefficient and fluidity index) and viscoelastic properties were correlated with flow table tests, relative density measurements, water retention abilities of mortars and air content in mortars. Results were seen to be strongly dependent on substituents of the chitosan. Non-ionic derivative (HPCH) had a plasticizing influence on the mortars; the ionic CMCH showed the thickening effect. The effect of chitosan ethers was found to be dosage-dependent. CMCH had low impact on water retention, while HPCH displayed high water retention capability. It was concluded, that the ionic derivative (CMCH) is very similar by its viscosity enhancing effect to starch ether.