Rasha A. El-Ghazawy

Preparation the Esters of Oleic Acid-Maleic Anhydride Copolymer and Their Evaluation as Flow Improvers for Waxy Crude Oil

Five comb-like copolymers derived from oleic acid-maleic anhydride were prepared and then esterified by long-chain fatty alcohol (POMA Cn), where n = 18, 20, 22. These polymers were characterized by FTIR and 1H NMR analysis. The molecular weight was determined by using gel permeation chromatography (GPC). The prepared copolymers were investigated as flow improvers and pour point depressants (PPD) for crude oil. From the evaluation, it was found that, the maximum depression of PP was obtained by (POMA2 C22) with long-chain alcohol (C22–OH) from 27°C to 15°C (ΔPP3000ppm = −12°C). On the other side, it was remarked that no depression obtained by (POMA2 C18), which esterified by alcohol (C18–OH) at the same condition. The depression of pour point effectiveness was discussed on the light of polymers structure, molecular weights, and their concentrations. By analysis the results of the rheological flow properties, it was found that the POMA2 C22 enhanced the Bingham yield values (τβ). The τβ for crude oil without additives against 15, 27, and 39°C were 0.286, 0.131, and 0.075 Pa respectively, whereas the τβ for the treated crude oil with POMA2 C22 were 0.027, 0.022 and 0.010 Pa at 3000 ppm at the same temperatures. By using the photomicrography analysis, it was found that, the wax morphology was greatly modified to fine dispersed crystals of compact size.

Effect of chemical crosslinking on swelling parameters of modified poly(vinyl alcohol) hydrogel

Graft copolymerization of maleic anhydride (MA) onto partially and fully hydrolyzed poly(vinyl alcohol), PVA, was carried out in presence and in absence of an initiator. The structural features of these grafts were confirmed by 1 HNMR analysis. 1 HNMR analysis was also used to determine the percentage of grafting. These grafts were crosslinked using different concentrations of either 1,1,1-trimethylolpropane trimethacrylate (TPT) or methylene bisacrylamide (MBA) as Hexa- or tetra-functional crosslinker, respectively. The crosslinkers concentrations ranged from 1% to 30% (wt.%) based on the total weight of grafts. The final water content, volume fraction of the polymer and swelling capacity were determined for all grafts. The effect of MBA and TPT crosslinkers structure on swelling properties of both partially and fully hydrolyzed PVA grafts were also determined.

Synthesis and Evaluation of Some Novel Polymeric Surfactants Based on Aromatic Amines Used as Wax Dispersant for Waxy Gas Oil

Dicarboxy methyl ethoxylated aniline and 1,3‐dicarboxy methoxy benzene were synthesized as intermediate monomers to prepare six polyester surfactants. The first three of them were obtained by polyesterification of dicarboxy methoxy ethoxylated (EO=10) aniline with polyethylene glycol (M. wt.; 400, 600, 1000). The product named as An E10 400, An E10 600, and An E10 1000. The later three was obtained by polyesterification of 1, 3 dicarboxymethoxy benzene with the same PEG at different molecular weights. The product named as; R 400, R 600, and R 1000. These polyesters were characterized by FT.ir, and GPC. These polyesters were evaluated as pour point depressants of a mixed blend of Egyptian Western desert gas oil, (PP=18oC). The obtained data showed that, the maximum reduction of pour point was obtained with An E10 1000 (ΔPP=15°C) and R 1000 (ΔPP=18°C) regarding to the two groups of polyesters respectively. Blends from these compounds were done. From the results, it was found that, the blend IV exhibit the maximum depression of pour point, (ΔPP=24°C). The photomicrographic investigation for the change of wax crystals morphology and size as the results of using the pour point dispersants was carried out after the treatment by the blends. The photomicrographic pictures showed a great modification of wax crystals was obtained as a result of dispersion of wax by the additives. The results were compared with a commercial additive at 1000 ppm. It was found that, its ΔPP=18°C. This work was extended to study the surface active properties of these polyesters at liquid/air interface. The obtained data were used to explain the discrepancy of these polyesters toward pour point depression.

Synthesis and Preliminary Demulsification Efficiency Evaluation of New Demulsifiers Based on Fatty Oils

Three raw fatty oils were used as precursors for demulsifiers. The hydrolyzed form of each oil was adducted with maleic anhydride then modified by esterification with polyethylene glycols or ethyleneoxide-propyleneoxide block copolymers. The demulsfication efficiency, coalescence rate, some surface active, thermodynamic properties, and partition coefficient of a selected demulsifier were investigated. The best demulsifier shows 100% demulsification after 19 minutes at 300 ppm. A correlation between demulsification efficiency and rheological properties of the investigated demulsifier was investigated. Also, emulsification kinetics were followed by microscopic photography. A mechanism following coalescence and flocculation of water droplets is proposed.

Castor Oil Based Organogels: I. Synthesis, Swelling, and Network Parameters

Linear and branched polyesters were prepared by transesterification of methyl recinoleate without or with diethylene glycol, trimethylol propane or pentaerithirtol for different durations. Molecular weight of the synthesized polyesters were determined using gel permeation chromatography and hydroxyl number. Their chemical structure were characterized by FTIR. Crosslinked polyesters were prepared using different weight ratios of trimethylolpropane triacrylate in presence of benzoyl peroxide initiator. These organogels were characterized through soluble fraction and toluene sorption capacity. Swelling kinetics and network parameters including polymer solvent interaction, effective and theoretical crosslink densities, average molecular weight between crosslinks and modulus of elasticity were determined.

Synthesis of Rigid Polyurethane Foams from Recycled Poly(ethylene Terephthalate) Waste

Glycolysis of poly(ethylene terephthalate), PET, waste using trimethylol propane (TMP) or pentaerytheritol (PEr) was used to produce suitable hydroxyoligomers for polyurethane foams. The glycolysis was carried out in the presence of manganese acetate as a catalyst, under high and normal pressure atmosphere in xylene and m-cresol at 220 °C. The prepared oligomers were reacted with 2,4- 2,6- toluene diisocyanate to produce different types of polyurethane foams. The compressive and flexural strengths, open and closed cell%, oxygen index% and curing times were determined and the results were correlated to the chemical structure of the produced oligomers.

Adsorption of Polymeric Additives Based on Vinyl Acetate Copolymers as Wax Dispersant and Its Relevance to Polymer Crystallization Mechanisms

The present work has main target to study the effect of additives molecular weight and composition on the flow characteristics of wax crude oil at low temperature below pour point temperature. In this respect, maleic anhydride ester-co-vinyl acetate copolymers with varied monomers feed ratios and different alkyl ester lengths, namely, dodecyl, stearyl, and behenyl alkyl chains, were prepared. These polymeric materials were characterized by FTIR, 1HNMR, and GPC. The performance of these additives as pour point depressants and flow improver for Egyptian waxy crude oil was evaluated through measurements of pour point and rheological parameters (viscosity and yield stress). It was observed that stearyl maleate-vinyl acetate copolymer with 1 : 2 feed ratio shows the best efficiency as pour point depressant even at low concentration while octadecyl maleate-vinyl acetate copolymers with 2 : 1 feed ratio are effective as flow improver.

Characterization of modified styrene-co-2-acrylamido-2-methylpropane sulfonic acid magnetite nanoparticles

This work provides an insight into the effect of incorporating of magnetite nanoparticles on the rheology of fluids. In this respect, polymer-stabilized magnetite nanoparticles were obtained using sodium salt of poly (2-acrylamido-2-methylpropanesulfonate (PAMPS-Na). Monodisperse polymer coated magnetite nanoparticles Fe3O4/poly(styrene-AMPS) copolymer nanoparticles with diameters of 50–300 nm were prepared by radical polymerization in the presence of a ferrofluid coated with PAMPS-Na. The magnetic nanoparticles were easily separated in a magnetic field. The structure of the obtained magnetic nanoparticles was characterized by Fourier transform infrared spectroscopy (FTIR). The morphology and size of the magnetic nanoparticles were determined by transmission electron microscopy (TEM). FTIR and TEM revealed that the Fe3O4 nanoparticles were incorporated into the shells of poly(styrene-AMPS). Aqueous dispersed solutions of a charged hydrophobically modified Fe3O4/poly(styrene-AMPS) copolymer nanoparticles exhibit high viscosities even at low polymer concentrations (0.1 wt %), which is an interesting feature in connection with enhanced oil recovery. Effects of temperature and addition of sodium chloride on the viscosity properties of a semidilute dispersed solution of Fe3O4/poly(styrene-AMPS) copolymer nanoparticles are examined. The results indicated that Fe3O4/poly(styrene-AMPS) copolymer nanoparticles disclose strong interactions between magnetite and coated polymers of both PAMPS-Na and styrene-AMPS copolymers.

Synthesis and Evaluation of New Demulsifiers Incorporating Linear Alkyl Benzene Moiety for Treating Water-in-Oil Emulsion

In the present study, five types of water soluble demulsifiers based on linear alkyl benzene were prepared. The chemical structures of the prepared demulsifiers were elucidated using Fourier transform-infrared (FTIR) and 1H NMR spectra. Different factors affecting demulsification efficiency such as; water content, demulsifier concentration, hydrophilic lipophilic balance (HLB), and ethylene oxide unit were investigated. Also, the rheological properties in relation to demulsification efficiency were studied. The surface and thermodynamic parameters of the prepared demulsifiers were determined at 25°C including, surface tension (γ) and effectiveness, maximum surface excess (Γmax), and minimum surface area (Amin). From the obtained data, it was found that the demulsification efficiency increases with increasing the water content and concentration of the demulsifiers. Primarily evaluation study of demulsification performance of the new demulsifiers showed that as the ethylene oxide unit in the demulsifiers increase (10–40 ethylene oxide units), the performance of the demulsifiers increasing, however, it decrease in case of demulsifiers with (80 ethylene oxide unit).

Synthesis and Surface Active Properties of Ethoxyalted 4,5-Dihydroimidazoline Surfactants

Pure oleic acid and four hydrolyzed products of locally fatty oils (namely, coconut, soybean, linseed, and castor oils) were monoesterified individually with two different polyalkylene polyamines. The produced monoesters were used as precursors for imidazoline derivatives. These oil soluble imidazolines were ethoxylated by ethylene oxide gas with different ethylene oxide contents (5, 10, and 20) to prepare water soluble stable imidazoline ethoxylates. The chemical structure of the synthesized imidazoline ethoxylates were justified through spectroscopy and surface active properties of the compounds were investigated. The obtained data were discussed on the basis of variation chemical structure.