Of Amps And Acrylic Polymerization Reaction And Applied Research

Super absorbents are hydrophilic crosslinked polymers which can imbibe huge amounts of water. They are used mainly as absorbents in healthcare, communication technology, building industry, chromatography, water purification, and agricultural applications. On the basis of surveying super absorbents' synthesis and application inside and outside country, a series of super absorbents was synthesized by means of aqueous polymerization and microwave catalysis polymerization with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and acrylic acid (AA) as raw materials. The study showed that the super absorbent synthesized by copolymerization of AMPS and acrylic acid by means of aqueous polymerization has excellent anti-salt performance and can absorb a large amount of water. The main contents of experiments were as follows:A series of super absorbents were synthesized by means of aqueous polymerization with industrial grade acrylic acid and AMPS as raw materials, N,N'-methylenebis-acrylamde as cross linker and potassium persulfate as initiator. The influence of such factors as mol ratio of monomer, crosslinker concentration, initiator concentration, neutralization of AA, ignite temperature was discussed in detail. The results showed that super absorbent synthesized under optimize terms can absorb water as high as 525 g/g and 0.9% NaCl solution 78 g/g. Experiments show that the resin has excellent anti-salt performance.Research on the super absorbent's water and different salt solution absorbing and retaining capability was studied by mathematical fit. At the same time the resin's anti-salt performance was discussed initially.To acquire better performance absorbent, vacuum distillated acrylic acid was used as raw material, and four factors affecting absorbent's performance were selected to proceed L9(34) orthogonal experiments on the basis of mono-factor test. The optimization factors were determined to be: acrylic acid neutralization: 90%; monomer mol ratio AMPS:AA=15:85; amount of crosslinker: 0.025% of totalmonomers; amount of initiator: 0.05% of total monomers. The results showed thatsuper absorbent synthesized under optimize terms can absorb water as much as 990 g/g and 0.9% NaCl solution 128 g/g.Still super absorbent synthesized by microwave catalysis polymerization was attempted. Experiments showed that power of microwave oven and microwave heating time can obviously affect super absorbent's performance. Absorbent that can absorb as high as 400 g/g water was obtained but the performance was not better than the resin synthesized by aqueous solution polymerization.The kinetics of copolymerization of AMPS and AA was studied by using dilatometer. Experiments showed that the kinetics equation of comolymerization AMPS and acrylic acid r[I]057[AMPS]"4[AA]086 . The reaction activity energy is about 123kJ-mor'. The mechanism of copolymerization of AMPS and acrylic acid follows mechanism of free radical.