Preparation,Characterization And Properties Of Betaine Acrylamide Polymer

Betaine-type polymers,contain the same number of cationic and anionic groups on the molecular chain,are one of the typical zwitterionic polymers.The betaine-type structure gives the polymer molecules some unique properties,such as electrical neutral and unique anti-polyelectrolyte behavior,and it can effectively improve the shortcomings of poor salt and high temperature resistance,low viscosity,and poor shear resistance of the polymer.Therefore,the polymers containing betaine structure has potential application value in the fields of tertiary oil recovery industry,drug release,antithrombotic materials,catalyst carriers,sensors and the like.The study of betaine-type polymers began as early as the 1960s,and the research heat of betaine-type polymers has been on the rise over the next few decades.In this paper,the betaine-type amphoteric monomer2-methacryloyloxy long-chain alkyl acid ammonium bromide(DMAC₁₁)was synthesized with dimethylaminoethyl methacrylate?DMAEMA?and long carbon chain alkyl acid as the main raw materials.The betaine-type amphoteric monomer DMAC₁₁and its copolymer with acrylamide?AM?(referred to as P(DMAC₁₁-co-AM)series)are the main research objects.Firstly,the chemical structure of the carboxybetaine monomer DMAC₁₁and its copolymer was characterized by NMR.The isoelectric point of DMAC₁₁measured by conductivity method is about 7.5,and the foaming performance and critical micelle concentration?CMC?of DMAC₁₁were measured under alkaline and acidic conditions.The results show that DMAC₁₁shows good performance in acidic or alkaline environment.The critical solution temperature?Kraff point?of DMAC₁₁was then determined by UV spectrophotometry,and the value is about 10?.Secondly,a betaine-type amphoteric acrylamide copolymer P(DMAC₁₁-co-AM)series composed of DMAC₁₁and AM was synthesized by free radical aqueous solution polymerization.The best synthesis process is obtained by changing the reaction conditions,that is,the molar fraction of DMAC₁₁in the total monomer is 3%,the total monomer concentration is 20wt%,the reaction temperature is 45?,and the reaction time is 24h.The rheological and erbium fluorescence probes were used to study the hydrophobic association properties of P(DMAC₁₁-co-AM)series copolymers and the effects of solution concentration and p H on the performance of P(DMAC₁₁-co-AM)solutions.The results show that PDA-10-5 has the strongest hydrophobic association property,and as the p H value increases,the PDA polymer changes from dissolving to insoluble and re-dissolving.One kind of hydrophobic association hydrogels(DMAC₁₁-AM-gels series)composed of DMAC₁₁and AM was prepared by free radical aqueous solution polymerization.The swelling behavior of a series of different components of DMAC₁₁-AM-gels in aqueous medium at 25?shows that the swelling performance of DMAC₁₁-AM-gels is negatively correlated with the total monomer and betaine monomer content.Based on the anti-polyelectrolyte properties of DMAC₁₁-AM-gels,the effects of salt solution and temperature on the swelling behavior of DMAC₁₁-AM-gels were studied.The deswelling kinetics model was used to calculate and description the swelling kinetics of DMAC₁₁-AM-gels.