الفهرس | Only 14 pages are availabe for public view |
Abstract Water-in-crude oil emulsions stabilized by natural surface-active components (such as asphaltene) are one of the major problems in relation to petroleum production. New water soluble nonionic amphiphilic block and graft copolymers based on hyDROPhilic poly (ethylene glycol) (PEG) and hyDROPhobic poly (propylene oxide) (PPO) were prepared. PEG-PPO-PEG copolymers were prepared in the normal condition by two methods to use them as demulsifiers for synthetic crude oil emulsions. In the first method PPO was esterified with MA to produce poly (propylene oxide) maleate diester. The produced polymers were esterified with PEG having different molecular weights to produce PEG-PPO-PEG block copolymers. The second method was based on grafting of MA onto PPO followed by esterification with PEG. The first step in this work is to polymerize propylene glycol and propylene oxide using KOH as a catalyst to produce poly (propylene glycol), PPO1, at the reaction temperature 298 K. The reaction time was adjusted to produce PPO having different molecular weights. The molecular weights of the prepared PEG-PPO-PEG block copolymers were determined by GPC technique. The structure of the prepared surfactants was illustrated by IR and 1H-NMR spectra. The surface activity of the prepared surfactants was determined from the surface and thermodynamic properties of these surfactants. The evaluation of the prepared poly(oxyethylene)-co-poly(oxypropylene) block and graft copolymers as demulsifiers for water-in-crude oil emulsions was carried out at 318 and 333 K. Data indicated that the prepared demulsifiers showed good demulsification efficiencies towards the different types of water-in-crude oil emulsions |