Analysis of the wetting behaviour of pigments and the effectiveness of surfactants

Abstract

A new test method is introduced to analyse the wetting behaviour of pigments and the effectiveness of surfactants. The method involves the study of torque vs time curves obtained during the wetting of pigments by surfactant solutions. These curves provide valuable information regarding the wetting behaviour of pigments and the ability of the surfactant to wet the pigment. To study the wetting behaviour, two pigments which varied widely in their surface character are studied with the same surfactant, while, to study the effectiveness of the surfactant, different surfactants with differing polarity are studied using the same pigment. The results are found to be consistent with the theoretical expectations.

Influence of the Processing Parameters on the Dispersion and Coloration Behavior of a Halogenated Copper Phthalocyanine‐Based Masterbatch

“…Shear stresses are related to pressure variation before and after passing through capillary, while shear rates are related to the throughput of material, as reported in Eqs. 7and (8).…”

“…This process can be improved by utilizing elevated processing temperatures and a low-viscosity matrix. 8,9 The dispersion quality of the pigments in the host polymer and their aggregation tendency depend on the physical properties of pigment particles (i.e., size, shape, surface properties, crystalline structure, chemical composition of the primary crystals). 4 On the contrary, pigment aggregation during the production process leads to heavy technical limitations like reduction of the mechanical properties, filament breakage during spinning, bad coloration quality, and economical disadvantages due to the increase in the production times and scraps.…”

“…3 Joshi et al investigated the effect of surfactant agent on the particle dispersion by measuring torque variation in the extruder during the compounding process. 8 Wo et al investigated the effect of phthalocyanine pigments on the crystallization behavior of polypropylene. 7 Ahmed et al compared the mechanical properties of polypropylene fibers obtained using pigments in powder form and monodispersed masterbatches.…”

Coloration properties and chemo‐rheological characterization of a dioxazine pigment‐based monodispersed masterbatch

“…Elevated shear stress during the extrusion promotes the breakage of primary particles aggregates and improve polymer‐particles wettability. This process can be favored applying elevated processing temperatures and by using a low viscosity matrix . Pigment dispersion in the polymer matrix and their agglomeration propensity depend on the properties of the filler (i.e.…”

“…According to our knowledge, only few articles focused on the analysis of monodispersed masterbatch production process and to the optimization of pigments dispersion in polymer matrices can be found in the open literature. For instance, Joshi et al evaluated the effect of surfactant agent on the particles dispersion by measuring torque variation in the extruder during the melt compounding . Suresh et al investigated pigments dispersion in a low density polyethylene matrix comparing different kinds of monodispersed masterbatches .…”