Studies on pour point depression of EVA polymers in solvent mixtures containing wax

Abstract

ABSTRACT:Measurements of the change of the pour point depression (⌬T PP ) were performed for the wax solutions made of four solvent mixtures: ethyl acetate/hexane (EA/HEX), 1,2-dichloroethane/cyclohexane (DCE/CYH), butanone/heptane (MEK/ HEP), and acetone/chloroform (AC/CF) doped with EVA polymers. The values of ⌬T PP increase significantly with increasing of the selective solvent EA, DCE, MEK, and AC components, for the vinyl acetate (VA) segment in EVA copolymers, in the solvent mixtures. The solvent effect of ⌬T PP occurring in wax solutions can also come from the solutions of EVA polymer, which were prepared by solvent mixtures with various compositions and used as parent solutions of EVA pour point depressant. From the experimental results such as the NMR of EVA macromolecules; viscosities of EVA, waxes, and their blends; and solubilities of wax with and without EVA macromolecules in the solvent mixtures, the complexation between wax molecules and ordered ethylene segment, and wax solubilization within ordered ethylene segments in EVA macromolecules are suggested for qualitative description of the observed significant variation of ⌬T PP .

Recent advances on mitigating wax problem using polymeric wax crystal modifier

“…25 wt% p-xylene, which could give up to 53 % reduction in the amount of wax deposition. Therefore, the formulation of wax inhibitors must be optimized before application due to the significant influence of solvent(s) (Qian et al 2002).…”

Control of n-alkanes crystallization by ethylene–vinyl acetate copolymers

“…However, the action mechanism of the EVA copolymer is still unclear in spite of several investigations performed by means of viscosity measurements of EVA solutions [29][30][31], DSC [32,33], and reaction calorimetry [34]. One obstacle to academic research in this field is the strong dependence of the properties on the composition of the paraffin mixture and the matrix.…”

Study on chain deformation of polyacrylamides in solutions and its flocculation performance during the flocculation process

“…As discussed above, we believe that the chain dimension or hydrodynamic volume and its conformation or shape of a polymer flocculant in a given system should be of importance for a better flocculation performance. We have reported the influence of incipient chain dimension of ethylene‐vinyl acetate (EVA) copolymer flow improver, in parent solutions, on the rheological behavior of waxy solvents, waxy kerosene and crude oil 17–19. In fact, Brostow et al20 even explained the increase of drag reduction efficiency of flowing liquids with polymer additives in term of the decrease of chain overlap produced by deformation.…”