Studies on Phenol‐Formaldehyde Gel Formation at a High Temperature and at Different pH

Abstract

une solution de phénol-formaldéhyde dans l'eau à une température élevée proche de 140 °C. On a trouvé expérimentalement qu'à une température entre 135 °C et 140 °C, une solution contenant 3,0 % de phénol avec un rapport molaire de phénol-formaldéhyde de 1,0:3,5 formait un gel ayant un pH compris entre 9,6 et 12,0. Le temps de gélifi cation minimum est observé à une valeur de pH de 10,4. La formation de gel s'avère fortement dépendante du pH à cette température élevée. On présente une explication pour le comportement de gélifi cation, qui s'appuie sur une concentration d'ions optimale de Na+ pour initier la formation de tri-méthylol. On pose comme hypothèse que la formation de gel commence quand la concentration de phénol de tri-méthylol atteint une valeur de concentration seuil. Des observations expérimentales et une analyse cinétique appuient cette hypothèse.

Air-oxidation of phenolic resin aerogels: backbone reorganization, formation of ring-fused pyrylium cations, and the effect on microporous carbons with enhanced surface areas

“…41 The closest prior studies ever came to pyrylium had been to claim saturated veand six-membered rings with oxygen between aromatic rings. [57][58][59][60][61] On the hindsight, it seems that key to our ndings was the fact that we compared the oxidative behavior of several systems of increasing complexity, which turned out to be benecial, because it allowed us to track the fate of aromatic carbons using solid-state 13 C NMR. Whenever an early oxidative ring-fusion aromatization could take place (cases of TPOL and FPOL), its effect was to rigidize the polymeric structure and create microporosity that contributed towards carbons with higher surface areas than those obtained by direct pyrolysis of as-prepared materials.…”

Study of a Profile Control Agent Applied in an Offshore Oilfield

“…With pH increasing, many carboxyl groups were produced by the hydrolyisis of amide groups, which led the degree of hydrolysis to increase and prolonged the gelation time. The polycondensation reaction of PFR was conducted under low pH (Albonico et al, 1995;Banerjee et al, 2006;Limei et al, 2008b).…”

Dynamic and static gelation behavior of phenol formaldehyde resin gel system in ampoule bottles and porous media

“…The proven technology of water shutoff and conformance control used polymer gel has been widely introduced to block the high permeable zone, realize in-depth flow diversion and enhance sweep efficiency (James et al, 2003;Mercado et al, 2009;Ojukwu et al, 2007;Wang et al, 2019;Zhou et al, 2020). Several kinds of polymer gels have been used in oilfield, including inorganic metal ions gel system (McCool et al, 2009), Phenol Formaldehyde Resin (PFR) gel system (Banerjee et al, 2006), polyethyleneimine gel system (Al-Muntasheri et al, 2009) and so on. Among these gel systems, due to the controllable gelation time and stable plugging ability, the PFR gel is widely used in conformance control and water plugging operations in oil fields.…”

“…Albonico et al (1995) studied the effects of pH, temperature, concentrations of polymer and crosslinker on gelation, injectivity of gelant and thermal stability in bulk and in porous media. Herbas et al (2004) and Banerjee et al (2006) studied the reaction rate of PFR gel and effects of pH and temperature on reaction rate.…”