Study on Morphology and Rheological Property of Organoclay Dispersions in Soybean Oil Fatty Acid Ethyl Ester over a Wide Temperature Range

Abstract

This work attempted to establish the relationship between the dispersion morphology and the viscous flow behavior of clay dispersions in soybean oil fatty acid ethyl ester (FAEE) at 2 and 65 °C. The clays used in this study include raw montmorillonite (Mt) and three kinds of organoclays prepared by ion exchange modification of Mt by cetyltrimethylammonium chloride (OC16), dihexadecyldimethylammonium chloride (ODC16), and trihexadecylmethylammonium chloride (OTC16), respectively. The X-ray diffraction and water contact angle results demonstrated that greater alkyl chain number of surfactants led to greater interlayer space and stronger hydrophobicity of organoclays. Due to the good affinity of the surfactant and FAEE, OC16 exhibited the most stable dispersion in FAEE between 2–65 °C, which resulted in the best flat rheological property. The molecular structures of multiple chain surfactants were quite different from that of FAEE, resulting in weak affinity between organoclays (ODC16 and OTC16) and FAEE. The sheets of ODC16 and OTC16 tended to aggregate at 2 °C, forming a gel structure, thus significantly increasing the low shear rate viscosity (LSRV) and yield stress. At 65 °C, with the expansion of FAEE and the stronger thermal motion of sheets, the dispersions of ODC16 and OTC16 were improved, destroying the original gel structure and resulting in significant decreases in LSRV and yield stress. This study confirmed that stable clay/FAEE dispersions tended to exhibit flat rheology, which could serve as a basis for the application of clay/biodiesel dispersion in deep-water drilling.

A Comparative Study on the Roll-to-Roll Processing of a Silicate–Polyvinyl Alcohol Composite Barrier Lacquer Using Slot-Die and Reverse Gravure Coating Techniques

“…In both coating techniques, the parameter sets used led to a shear rate, which was in turn accompanied by a viscosity that started to become approximately constant, or at least to a viscosity not in the area of strong exponential decay at low shear rates from 10 to 200 1 s . All of the formulations provided a shear-thinning behavior similar to PVA solutions [53] and MMT dispersions [54]. Without any shear force, the PVA chains were oriented randomly in the lacquer, as were the MMT platelets.…”

Sustainable Polyurethane–Lignin Aqueous Dispersions and Thin Films: Rheological Behavior and Thermomechanical Properties

“…Therefore, it is very crucial to investigate and understand the rheological behavior of polymer dispersions so that they can be accurately formulated and used in a reproducible manner. Dynamic rheology is a powerful technique to investigate the rheological behavior of polymeric materials including thermoplastics, thermosets, dispersions, and nanocomposites. − In this section, the effect of LS on the dynamic viscosity of PU–LS dispersions of different compositions of LS and angular frequency in the linear viscoelastic regime will be investigated at room temperature. Figure demonstrates the complex viscosity at different angular frequencies for PU–LS dispersions with different contents of LS at 20 °C and under 1 strain %.…”