The granulometric composition and the rheological properties were studied in respectively PVC powders and plastisols prepared from continuous emulsion-polymerized PVC E-68 latexes in relation to the proportions of nonionic and anionic co-emulsifiers added prior to the latex drying step. Ethoxylated lauryl alcohol (Rewapol LA-6) and ethoxylated alkylphenol (Rokanol N-8) were used as nonionic co-emulsifiers. Sodium 2-ethylhexylsulfosuccinate, sodium salt of ethoxylated nonylphenylsulfosuccinate, and amidated styrene/maleic anhydride copolymers of varying molecular weights were used as anionic co-emulsifiers. The proportions were varied from 0.08 to 0.8 weight part co-emulsifier per 100 weight parts PVC in the latex. Plastisols were prepared from 100 weight parts PVC and 70 weight parts di(2- thylhexyl)phthalate and stored for 24 h. Their rheological properties were studied by measuring viscosities at shear rates of 1.0 to 145.8 sec"1 and by evaluating viscosity variations over the shear rate interval 1.0-48.6 sec"1. The two nonionics and sodium 2-ethylhexylsulfosuccinate were found to depress the plastisol viscosity. Sodium salt of ethoxylated nonylphenylsulfosuccinate prevented the original latex granules from agglutinating and allowed to prepare viscostable plastisols. The copolymer resulted in large agglomerated latex granules hard to disintegrate in the plasticizer and thus in high-viscous inferior plastisols.
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