Synthesis Of Dendrimer And Its Demulsification For The Simulated Oil-Polluted Water

Dendrimers are a new category of dendritic macromolecules, which have three-dimensional, highly ordered and monodisperse structures. The size, shape, structure and functions groups of molecular can be controled and designed at the molecular level. According to the unique structures, great attention has been paid to development of functions and purposes of dendrimers currently.In this paper, 0.5G～3.0G (generation) polyamidoamine dendrimers were synthesized. The integrated generation PAMAM were modified to novel PAMAM modified cationic dendrimer. The structures of products were characterized.Their surface activity were measured. The demulsification performance for the simulated Oil-Polluted Water of the integrated generation PAMAM and modified products were studied. The main results are as follow:1. 0.5G～3.0G polyamidoamine dendrimers were synthesized by divergent method with ethylenediamine core through repetitive Michael addition and amidation. Adopting infrared spectrums,nuclear magnetism resonances and terminal analysis means to characterize their structure,the results indicate that the products is in conformity with their theory structure. Furthermore the optimized synthesis conditions of 0.5G and 1.0G PAMAM were studied on reaction temperature, reaction time and material ratio and so on.2. The integrated generation PAMAM dendrimers were modified to novel PAMAM modified cationic dendrimer(M-PAMAM)using tertiary amines and epichlorohydrin in one-step reaction. The optimized synthesis conditions were studied on eaction temperature, reaction time and material ratio. Adopting infrared spectrums,nuclear magnetism resonances meaned to characterize their structures,the results indicate that the products are in conformity with their theory structures.3. The surface activity of aqueous solution of PAMAM and modified products were studied by maximium bubble pressure method. It is found that the half generation PAMAM dendrimers have lower surface activities than that of traditional surfactant. The integrated generation PAMAM dendrimers have no surface activity almost. The PAMAM modified cationic dendrimers have fine surface activity.4. The demulsification performance for the simulated Oil-Polluted water of the integrated generation PAMAM and modified products were studied in this paper. The inluence of temperature,degree of branching, concentration and time of products on demulsification were studied.The result shows: the integral generation PAMAM have approved demulsification performance. At 40℃with additive concentration of 120 mg/ L ,the dehydration rate of 3.0 G PAMAM for simulated Oil-Polluted Water during 90 min reached 90%. The demulsification performance improves with increase of its generation and concentration.The modified products have excellent demulsification performance for the simulated Oil-Polluted Water. The demulsification performance improves with increase of its generation and concentration. At 40℃with additive concentration of 120 mg/ L , 90 min the dehydration rate of 3.0 G PAMAM modified cationic dendrimer for simulated Oil-Polluted water beyond 90%, which indicates that the demulsification performance of M-PAMAM is higher than that of PAMAM.