Preparation And Inclusion Process Of β - CD Inclusion Complex Modified By Bifunctional Groups

Oleic amide propyl betaine (OAPB) is used as the main agent of matrix acidizing in carbonate reservoirs in order to the achieve the diversion of acidizing fluid, which has caused extensive research at home and abroad. OAPB and the difunctional modified β-cyclodextrin derivative (Bifu-β-CD) obtained from the modification of β-cyclodextrin (P-CD) are used together for the main agent for diversion acidizing fluid acid, which is provided with great significance. In this paper, the molecular structure of the β-CD while introducing monostearate hydroxypropyl groups and glycidyl monostearate group are introduced to the molecular structure of the β-CD to obtain Bifu-β-CD with excellent properties. By the inclusion and assembly, the inclusion complexes of Bifu-P-CD and OAPB are formed. Then, the surface tension and static adsorption capacity of the inclusion complexes solution are investigated. Last, we evaluate the performance of diversion acidizing fluid (based on OAPB) having added Bifu-P-CD. The specific content of the research are as follows:(1) Synthesis of glycidyl monostearate (GM) and hydroxypropyl-β-cyclodextrin (HP-β-CD), Bifu-β-CD and OAPB:Adding a certain amount of phase transfer catalyst, sodium stearate and epichlorohydrin reacted to prepare GM; Under the strongly alkaline environment of sodium hydroxide solution, β-CD and propylene oxide were used as raw materials to synthesize HP-β-CD; HP-β-CD and GM in Pyridine as solvent and organic base catalyst, Bifu-β-CD was obtained from the reaction of HP-β-CD and GM under theweakly alkaline environment; The two step reactions of OAPB synthesis are acylation and quaternization.(2) Structural characterization of GM, HP-β-CD, Bifu-β-CD and OAPB:FT-IR and’H NMR confirm that GM and HP-β-CD are formed; FT-IR,’H NMR and XRD can be used as the proof of formation of a new substance obtained from the reactioin of GM and HP-β-CD; FT-IR verifies OAPB was successfully synthesized.(3) Construction of the host-guest inclusion complexes of Bifu-P-CD and OAPB: The inclusion complexes of Bifu-β-CD and OAPB were obtained by ultrasonic. FT-IR and’H NMR together verify the formation of inclusion complexes, and SEM characterization visually observed viscous mesh structure of inclusion complexes. Inclusion competition and UV-vis spectroscopy determined12.35L/mmol of the inclusion constant and1:1of inclusion form.(4) Effect of Bifu-β-CD on OAPB solution and diversion acidizing fluid (based on OAPB):Bifu-P-CD reduced the surface tension and static adsorption capacity of OAPB solution to a certain extent, which is conducive to the flow of acidizing fluid at the beginning of treating and also weaken the adsorption retention. Compared with acidizing fluid (based on OAPB) without Bifu-β-CD, the one having added Bifu-β-CD were more conducive to the Tackifying and diversion of acidizing fluid.