| Polyacrylamide?PAM?has been widely used in many fields such as sewage treatment,enhanced oil recovery?EOR?,paper-making and construction industries because of its linear water-soluble macromolecular chain.However,with the development of society and the complicated change of the environment,traditional PAM gradually cannot meet the urgent needs of social development.Therefore,the development of novel functional monomers which can adapt to complicated environment has been an attractive topic.In this dissertation,acrylamide?AM?,acrylic acid?AA?,acryloxyethyltrimethyl ammonium chloride?DAC?,and novel cationic functional monomers containing different hydrophobic chain lengths and2-?acryloyloxy?-N1,N1,N3,N3-tetramethyl-N1,N3-dioctylpropane-1,3-diaminium?DC8?.P?AM-DAC?,P?AM-AA-SCn?and P?AM-AA-DC8?were obtained by using an aqueous polymerization and compound initiation system.The intrinsic viscosity of the polymer was used as a measurement index to examine the polymerization process.Factors such as initiator concentration,monomer concentration,p H and initiation temperature was studied to obtain the optimal synthesis process,and infrared spectroscopy?FT-IR?and nuclear magnetic resonance?1H-NMR?were used to analyze the polymer composition structure.At the meanwhile,a series of experiments was carried out to diagnose the flocculation,temperature tolerance and salt tolerance,etc..,and the detail overview is as follows:First,P?AM-DAC?was synthesized by AM and DAC via the compound initiation method in aqueous solution,and factors like DAC monomer content,2,2'-azobis[2-?2-imidazolin-2-yl?propane]dihydrochloride?V44?,the initiation temperature and 2,2'-azo?2-methyl-N-?2-hydroxyethyl?propanamide??V80?were studied in the polymerization process,and the optimal synthesis parameters was obtained:DAC accounted for the molar ratio of the total volume is 20%,the V44content is 0.25 wt%,the initiation temperature is 30oC,the V80 content is 0.5 wt%,and the intrinsic viscosity is 16.47 d L/g.At the same time,infrared spectrum and nuclear magnetic hydrogen spectrum confirmed that the DAC monomer has been successfully integrated into the polyacrylamide?PAM?main chain.Secondly,a series of novel cationic monomers?SCn?containing different hydrophobic chain lengths?n=1,4,8?were synthesized based on the structure of traditional DAC monomers.A cationic polymer P?AA-AM-SCn?was obtained via co-polymerization of AM and acrylic acid?AA?using the compound initiation system in aqueous solution.and SCnmonomer content was kept under the condition of 1%.As the result of the series of monomers have similar structures and polymerization process,the SC4monomer was used as example,factors like the oxidant content,the ratio of oxidant and reducing agent,V44/V50 content,AA content and p H were studied to obtain the optimal synthesis parameters:the oxidant ammonium persulfate content is 0.04 wt%,the molar ratio of oxidant and reducing agent?ammonium ferrous sulfate hexahydrate?is 1:1,the V44 content is 0.4 wt%,the molar ratio of AA is 20%and the p H is in the range of 6?7.finally the intrinsic viscosity of the polymer is as high as 28 d L/g.Nuclear magnetic hydrogen spectrum and infrared spectrum prove that the novel functional monomer has been successfully integrated to the PAM main chain.At the same time,flocculation experiments were carried out using sewage from paper mills and steel mills.The experimental results show that as the length of the hydrophobic segment increases,the light transmittance can reach97.9%,The removal rate of COD can reach 96%.Finally,in this paper,the structure was further modified to obtain the twin-tailed cationic hydrophobic monomer 2-?acryloyloxy?-N1,N1,N3,N3-tetramethyl-N1-nonyl-N3-octylpropane-1,3-diammonium bromide?DC8?.P?AM-AA-DC8?was obtained by co-polymerization with AM and AA using a micellar polymerization method.The V44 content,p H,AA and DC8content were studied based on the intrinsic viscosity and apparent viscosity,and the optimal synthesis parameters was obtained:the V44content was 0.6 wt%,the p H was between 7?8,and the molar content of AA was10%.Under the condition that the molar content of DC8is 1%,the intrinsic viscosity of the polymer is 16.47 d L/g.Nuclear magnetic hydrogen spectrum and infrared spectrum indicated that the functional monomer has been successfully connected to the PAM main chain.At the same time,the salt and temperature resistance of P?AM-AA-DC8?was tested.The results showed that the apparent viscosity retention rate was 70.4%at 50oC,and the apparent viscosity retention rate of the system was still 34.4%at 90oC.In terms of salt resistance,when the sodium chloride concentration reached to 35 g/L,the apparent viscosity appears an inflection point,and it increases with the increase of sodium chloride concentration,showing a certain salt resistance;In the interaction test of sodium lauryl sulfate?SDS?,the results showed that when the SDS concentration reached 0.15 wt%,the apparent viscosity reached 63.25 m Pa·s,which was greatly improved and indicated excellent synergy. |
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