Functionalized poly(vinyl alcohol) as a novel dispersant for cement slurries: Synthesis, characterization and evaluation.

• A novel comb-structural PMA-g-PVA was synthesized and used as a promising dispersant. • Functionalization of PVA can greatly enhance its thermal stability and dispersibility. • Good plasticizing and retention capacities were shown for wide potential applications. • Established a guiding equation for regulating the side chain length of comb polymer. • Innovative design on molecular topological transformation helped PVA performances. A novel dispersant for cement slurries or other suspensions was synthesized by graft copolymerization between maleic anhydride (MA) and end-functionalized poly(vinyl alcohol) (PVA) to produce comb polymer, i.e. PMA-g-PVA. The chemical structure was characterized by 1H Nuclear Magnetic Resonance (1H NMR), Infrared Spectroscopy (IR), Gel Permeation Chromatography (GPC), alcoholysis degree and element analysis. This functionalization of PVA can significantly enhance its thermal stability and dispersibility. The evaluations of PMA-g-PVA and PVA in cement slurries were comparatively discussed in detail. The results showed that PMA-g-PVA performed well in dispersing and dispersing retention capacities, presenting more excellent fluidities of cement slurry (~200 mm) with maintenance of >85% within 3 h, due to its strong ability of breaking large flocculated structures of cement particles to fine size and homogeneous dispersion. This new type of functionalized PVA may be introduced as a promising candidate for the rheology modifying superplasticizer in slurry or colloid materials. [ABSTRACT FROM AUTHOR]