Synthesis And Application Of The Highly Branched Nonionic Surfactants

Oil is the blood of modern industry. With the rapid development of our industry, our demand for oil is increasing. But when the water is inputted more and more, the water content ratio of outputted liquid form oil well is increasing high. So it has special significance to improve oil recovery ratio and make full use of limited oil resources. We synthesized some kinds of highly branched nonionic surfactants to deal with the outputted liquid form oil well. Finally, we try to improve the capability of the surfactants by crosslinking. We studied the physics and chemistry properties of the surfactants to find their rules.We use the gel permeation chromatography and nuclear magnetic resonance to analyze the structure and molecular weight. The highly branched nonionic surfactants was synthesized through varieties of initiators which have lots of branches with propylene oxide (PO) and ethylene oxide (EO). The influence of EO/PO,initiator and crosslink on the surface and interfacial properties, size of aggregates, turbidity properties and demulsification of the surfactants were investigated.The results indicated that, first, With the reduction of the initiator, or with the increase in quantity of initiator branch, the demulsifiers had larger molecular weight, dehydration rate of the demulsifier increased. When the ratio of the ethylene oxide and propylene oxide was between 3:7 to 1:4, the demulsifiers had good dehydration rate, and the demulsifier had the best dehydration effect when m (EO)/m (PO) value was 1:3. Second, With the degree of crosslink increase, the interfacial tension, the size of aggregates become larger, meanwhile it nearly has no influence on the surface tension and makes the cloud point decrease. Noteworthy, the radius of aggregates grow from 20 nm to 465 nm, as the crosslinker-polyether ratio increases from 0 to 0.04(wt); lastly, the increasing amount of the initiator branch could increase the molecular weight of nonionic surfactants and the ability of the emulsion breaking in some incrosslinking range. With the degree of crosslink increase, the molecular and the extent of demulsification become larger.