Study On Synthesis And Demulsification Of Branched Block Polyether

Poly (propylene oxide)-poly (ethylene oxide)(PPO-PEO) block polyethers are typical nonionic polymeric surfactants which have the characters of be rich in its designable speciality of structure and controllability of synthesis. They can form multiple mesoscopic aggregates in different solvent. PPO-PEO block polyethers have good interfacial absorption ability, good biocompatibility, and environment friendly. They are widely applied in fields of demulsification, cosmetics, wastewater treatment, paper making, controlled drug release, biological macromolecules separation and mesoporous materials preparation. The researches of the theory and application of linear block polyethers have been numerously reported, however, the studies on the block polyethers with branched structure are rarely published. Based on the previous researches, we synthesize the block polyethers with branched structure and we investigate the aggregation behaviors of block polyethers with different structures. We also studied the emulsion breaking ability of block polyethers and the modified demulsifiers for crude oil.1. A kind of novel phenol-amine resin was synthesized using tert-butylphenol, formaldehyde and tetraethylenepentamine as raw materials. Then a series of novel block polyethers (TB) were synthesized using phenol-amine resin as initiator through polymerization reaction with propylene oxide (PO) and ethylene oxide (EO). The structures and compositions of block polyethers (TB) were confirmed by1H-NMR spectra and the molecular weight of copolymer was obtained by means of static laser light scattering. The cloud points, water number and RSN (Relative Solubility Number) of block polyethers (TB) were measured, and the HLB value of them was calculated by the cloud point method. The aggregation behaviors at the air/water and n-heptane/water interface of block polyethers (TB) were investigated by the methods of equilibrium surface tension, dynamic surface tension, and interfacial dilational rheology. The results showed that the cloud points and the HLB values of the block polyethers (TB) decreased with the increasing ratio of initiator to PO and the decreasing of EO content; and the water number and RSN of the polyethers increased with the increasing ratio of initiator to PO and the decreasing of EO content. The aggregation behaviors of block polyethers (TB) in mineralized water were also investigated. The results indicated that as the numbers of PO groups increased the hydrophobicity of block polyether was stronger, the surface tension of water solution was lower, the efficiency and effectiveness to lower surface tension were stronger and the adsorption at the interface was easier. The results showed that the presence of salts can facilitate the adsorption at air/water interface. The surface tension and cmc (critical micellization concentration) decreased with the increasing of the temperature. The dilational modulus of block polyethers (TB) at air/water interface decreased with the increasing of the block polyether concentration and increased with the increasing of the frequency.2. The demulsification of block polyethers (TB) and demulsifier modified by toluene diisocyanate (TDI) was studied by the bottle testing method at laboratory and at oilfield. The demulsification of demulsifiers modified by four different crosslinkers was studied by the bottle testing method. The best demulsifier was TB6927and the water separation was85%in90min. The demulsification of demulsifiers modified by TDI was better than block polyethers (TB). The demulsification of TB6927was not improved with nano-silica direct dispersed in TB6927. The demulsification of demulsifiers modified by TDI, methylethoxylsilicone and nano-silica modified by KH550was improved.3. Tetraphenol ethane (TPE) was synthesized using phenol and glyoxal as raw materials. A kind of novel phenol-amine resin was synthesized using tetraphenol ethane, formaldehyde and tetraethylenepentamine as raw materials. Then a series of novel block polyethers (TP) were synthesized using phenol-amine resin as initiator through polymerization reaction with PO and EO. The structures and compositions of block polyethers (TP) were confirmed by1H-NMR and the molecular weight of copolymer was detected by means of static laser light scattering. The water number and RSN of block polyethers (TP) were measured. The results showed that the water number and RSN value of the polyethers increased with the increasing ratio of initiator to PO and the decreasing of EO content. The demulsification of block polyethers (TP) and demulsifier modified by toluene diisocyanatein (TDI) was studied by the bottle testing method at laboratory and at oilfield. There was no big difference of demulsification between at laboratory and at oilfield. The best demulsifier was TP19920and the water separation was88%in90min. The demulsification of demulsifiers modified by TDI was worse than block polyethers (TP).