Rheology and gelation kinetics of PVC plastisols

Oscillatory theological experiments at different temperatures and over a wide range of frequencies have been used to investigate the gelation process and, more particularly, the sol-gel transition of various poly(vinyl chloride) (PVC) plastisols. The sol-gel transition process was found to be universal with respect to the temperature and solid volume fraction according to the similarity of the fractal structure in PVC plastisols. The variation of the get time (t(gel)) with temperature for any composition of PVC plastisols was predicted from the Dickinson's model (E. Dickinson, J Chem Soc Faraday Trans, 93:111-114, 1997). Dynamic viscoelastic properties of PVC plastisols have also been studied as a function of temperature that allowed us to follow the gelation process of various plastisols. Thus, the influence of the type and concentration of PVC resins in getation process was investigated. The variation of the complex shear modulus at a constant frequency was depicted by a master curve regarding the dependence of the moduli on PVC concentrations.