Effect of polyvinylpyrrolidone on rheology of aqueous SiC suspensions with polyethylene glycol as binder

Abstract

The effect of polyvinylpyrrolidone (PVP) on rheology of aqueous SiC suspensions with polyethylene glycol (PEG) as binder was investigated. Results showed that in presence of PEG as binder, suspensions with addition of PVP at proper dosages resulted in better dispersion in comparison with conventional dispersant polyacrylic acids (PAA). As the total content of dispersants was fixed, PVP and PEG co-existing in the suspensions obtained lower viscosity than those added separately, and suspensions can be well dispersed in both neutral and alkaline conditions. The molecular weight of binder PEG showed no significant effect on the rheology of suspensions. Furthermore, the dispersion of SiC suspensions can be influenced by the addition modes due to synergistic effect between PEG and PVP. The association between them through intermolecular hydrogen bonding adsorbing on the particle surfaces provided enhanced steric hindrance and thus led to the system stability.