Preparation and properties of amphoteric polyacrylamide by seeded dispersion polymerization in ammonium sulfate solution

Abstract

Amphoteric polyacrylamide (AmPAM) was prepared successfully through seeded dispersion polymerization with acrylamide, methacrylatoethyl trimethyl ammonium chloride and acrylic acid as comonomers in ammonium sulfate solution. It was characterized by 1 H nuclear magnetic resonance ( 1 H NMR) and elemental analysis. The particle morphology and apparent viscosity of polymer dispersion were obtained by optical microscope and rotary viscometer, respectively. AmPAM dispersion was obtained with low apparent viscosity. The process was smooth without high viscosity stage. The data of 1 H NMR spectrum and elemental analysis indicated that all monomers had participated in the polymerization. The seeded reaction time and the mass ratio of two parts of monomers had significant effects on the dispersion polymerization. The best conditions were seeded reaction time 1.75h and the mass ratio 0.75. The apparent viscosity of AmPAM dispersion depended on the number of particles, particle size and low molecular weight polymer concentration in the continuous phase. AmPAM showed both anti-polyelectrolyte effect and polyelectrolyte effect.

A novel and controllable route for preparing high solid-content and low-viscosity poly(acrylamide-co-acrylic acid) aqueous latex dispersions

“…So the viscosity of the polymerization system would be very high with the most part of polymers dissolved in the continuous phase. When the total monomer concentration was higher than 20%, stable dispersion even could hardly been obtained by this method according to available reports [28][29][30][31][32] .…”

“…Wang reported the effects of the structure and molecular weight of the polyelectrolyte stabilizer on the dispersion polymerization of water-soluble monomers in aqueous inorganic salt media 23 . However, there still existed some inherent disadvantages: 1) the monomer concentration is very low (not higher than 20%), making for inefficiency in the workplace and higher cost in the transportation; 2) the resultant polymer's molecular weight can not reach the requirement of practical application (not higher than 7dL/g) [28][29][30][31][32] . These above-mentioned defects inhibit the development of this technology and its application in industry.…”

“…23 However, there still existed some inherent disadvantages: (1) the monomer concentration is very low (not higher than 20%), making for inefficiency in the workplace and higher cost in the transportation; (2) the resultant polymer's molecular weight can not reach the requirement of practical application (not higher than 7 dL g À1 ). [28][29][30][31][32] These above-mentioned defects inhibit the development of this technology and its application in industry. For in this type of dispersion polymerization, polymerization proceeded mostly in the continuous phase and the resultant polymers could not phase out in time from the continuous phase because the good solubility of the polymer.…”

“…When the total monomer concentration was higher than 20%, stable dispersion even could hardly been obtained by this method according to available reports. [28][29][30][31][32] In this article we proposed a distinctly novel strategy to fabricate poly(acrylamide-co-acrylic acid) aqueous latex dispersion. In our system, copolymers were formed through a diffusion and redox initialized polymerization restricted inside the seed particle.…”

Synthesis of hydrophobically modified flocculant by aqueous dispersion polymerization and its application in oily wastewater treatment

“…In contrast, aqueous dispersion polymerization provides an attractive alternative to synthesize fast‐soluble and environmental‐friendly PAM. Dispersion polymerization of AM with other water‐soluble monomers in aqueous media to synthesize the cationic, anionic, and amphoteric flocculants has been extensively studied . However, to our best knowledge, the report regarding the synthesis of hydrophobically modified flocculant through aqueous dispersion copolymerization of AM with hydrophobic monomer in aqueous salt solution is still few.…”