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 E-10 400, 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 FTJr, and GPC. These polyesters were evaluated as pour point depressants of a mixed blend of Egyptian Western desert gas oil, (PP = 18 degrees C. The obtained data showed that, the maximum reduction of pour point was obtained with An E10 1000 (APP = 15 degrees C and R 1000 (APP = 18 degrees 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, (APP = 24'Q. 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 APP = 18 degrees 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.