Cardanol acts to stabilize asphaltene particles in crude oil, but its derivative polycardanol, synthesized with BF3.O(C2H5)2 as initiator, exhibits divergent behavior, acting as both asphaltenes stabilizer and flocculant. This behavior could be related to structural differences in polycardanol samples. Therefore, in this work, we study the influence of some polymerization conditions (monomer purity, initiator concentration, and reaction time) on the structures and molar masses of the reaction products, and the reaction conversion. The materials were characterized by size exclusion chromatography and hydrogen and carbon nuclear magnetic resonance. When reacting with distilled cardanol, the conversion, the molar mass, and the homogeneity of structures increased as increasing initiator concentration in the range tested (1-3% m/m). For both monomers (different purity degrees), when using a lower initiator concentration (1% m/m), the product contained a larger amount of unreacted monomer and different structures were obtained due to the occurrence of rearrangements. The presence of triolefinic molecules in the monomer provoked crosslinked structures for higher initiator concentration (2-3% m/m). This study elucidated the differences among the reaction products of polycardanol.

Resumen Este estudio describe la síntesis de resinas poliméricas a base de estireno (STY), metacrilato de glicidilo (GMA) y divinilbenceno (DVB), modificadas químicamente mediante reacciones de sulfonación durante diferentes intervalos de tiempo, para conocer la influencia de la estructura de los materiales en su capacidad de adsorción y evaluar su potencial de aplicación en la remoción de amonio de aguas residuales a niveles que cumplan con la norma técnica NT202, R-10 (INEA, 1986). Los resultados mostraron que, además de la duración de la reacción de sulfonación, factores como el área superficial y el diámetro de los poros también contribuyeron significativamente al proceso de absorción de amonio. La eficácia de las formulaciones fue en orden decreciente DVB(7:3)(2)S, DVB(7:3)(24)S, STY-DVB(7:3)(2)S y GMA-DVB(7:3)(2)S. De estos, DVB(7:3)(2)S tenía la mayor área superficial pero tenía una baja capacidad de intercambio iónico. La resina con mayor capacidad de intercambio fue STY-DVB(7:3)(2)S, pero tuvo una eficiencia aproximadamente un 20% menor que la resina anterior, mostrando un resultado muy cercano al de GMA-DVB (7:3)(2)S.

Abstract This study describes the synthesis of polymeric resins based on styrene (STY), glycidyl methacrylate (GMA) and divinylbenzene (DVB), modified chemically through sulfonation reactions during different time intervals, to learn the influence of the materials’ structure on their adsorption capacity and evaluate their potential for application in the removal of ammonium from wastewater to levels compliant with the technical standard NT202, R-10 (INEA, 1986). The results showed that besides the duration of the sulfonation reaction, factors such as surface area and pore diameter also contributed significantly to the ammonium absorption process. The efficiency of the formulations was in decreasing order DVB(7:3)(2)S, DVB(7:3)(24)S, STY-DVB(7:3)(2)S and GMA-DVB(7:3)(2)S. Of these, DVB(7:3)(2)S had the greatest surface area but had low ion exchange capacity. The resin with the greatest exchange capacity was STY-DVB(7:3)(2)S, but it had efficiency about 20% lower than the former resin, showing a result very near that of GMA-DVB(7:3)(2)S.

Predicting the compatibility of crude oils from different streams can be done by applying models that use the solubility parameter of the oils. The approximate solubility parameter value of a given crude oil can be calculated by observing the asphaltene precipitation onset caused by titration with n-heptane. For oils whose precipitation onset is not well defined, a small quantity of another petroleum with easily detected onset can be added. It would be ideal to always use the same petroleum for this addition, but this is obviously not possible. The purpose of this study was to replace this petroleum by a synthetic molecule. Therefore, molecules were selected and synthesized to obtain structures containing aromatic ring, aliphatic chain and heteroatom. The molecules were characterized by infrared spectrometry, gas chromatography-mass spectrometry, elemental analysis and gel permeation chromatography. Nitrated cardanol, polycardanol obtained by addition polymerization (PCA) and nitrated PCA presented the desired behavior. However, the concentration of the molecule in toluene needs to be adjusted in function of the characteristics of the petroleum. For a particular crude oil, when model molecule present solubility in a wider solubility parameter range, lower concentration will require to identify the precipitation onset of that oil.