Preperation And Characterization Of Poly(N-Vinylamine-Acrylonitrile) Chelating Fiber

Chelating fiber is used as an adsorbent for heavy metal ions such as Cu²⁺, Cd²⁺, Hg²⁺, Cr³⁺, Ag⁺ and Au³⁺, because it contains N, O, S, P atoms which can chelate with many metal ions. Chelating fiber has more merits than chelating resin, such as smaller diameter, bigger surface area, and higher adsorption speed. Therefore, chelating fiber has the potential applications in the treatment of industrial wastewater, the condensation and the separation of metal ions and the trace of ions in solution.N-vinylformamide (NVF) is a functional vinyl monomer which easily forms water soluble or hydrophilic polymers with high molecular weight by radical polymerization. Hydrolyzing this polymer can convert the formamide group to the highly reactive amino group. Amino group can be used a cheland for metal ions. To copolymerize NVF and acrylonitrile (AN) is a good idea that combines the amino of the NVF's hydrolyzate with AN's excellent fiber forming ability. Chelating fiber can be achieved through hydrolyzing the fiber of the copolmer of NVF and AN.N-vinylformamide (NVF) and acrylonitrile (AN) copolymers were prepared via free radical solution copolymerization in the presence of azodiisobutyronitrile (AIBN) as an initiator. The effect of initiator concentration, monomer concentration and polymerization conditions on the monomer's conversion and intrinsic viscosity were investigated. The combination of kinetics and intrinsic viscosity study revealed the copolymerization adopting an alternating copolymerization mechanism. The results show that there is not obvious induction period in the copolymerization and reaction goes along evenly till the conversion up to 30%. Obvious autoacceleration phenomenon was not observed in the copolymerization.