Copolymer of acrylonitrile/acrylic acid solid surface film dendrigrafted with citric acid

Abstract

BACKGROUND: The aim of the present work was to improve the properties of acrylic polymer, which is a major fibre-forming polymer. Acrylonitrile/acrylic acid copolymer, P(AN/AA), was chosen for this purpose and it was intended to study the condition for the formation of hydroxyl groups through the formation of hyperbranched polymers. RESULTS:The synthesis of a dendritic polymer of citric acid (CA) in the solid phase on a P(AN/AA) core is described. The product was analysed using the elemental analysis technique and 1 H NMR. Dendritic molecules were grown by a reaction between the carboxylic acid of acrylic acid and hydroxyl group of CA activated by dicyclohexylcarbodiimide. Products were analysed using Fourier transform infrared and NMR spectroscopy. CONCLUSION:The formation of CA dendrigraft on P(AN/AA) films in a heterogeneous system is possible. The percentage conversion of the copolymer reaction with CA was calculated based on the NMR results. The percentage conversion showed a gradual reduction with an increase in step numbers. The contact angle of water on the films was affected by the percentage conversion of the reactions. A calculation scheme is presented to show that the low degree of conversion leads to an increase in hydrophobic groups.

Dendrigraft with citric acid on acrylonitrile/acrylic acid copolymer electrospun fibres

“…The integrated intensities of CH 2 signals of CA and P(AN/AA) in 1 H NMR spectral analysis were used to calculate the percentage conversion, as described previously . Figure shows that the percentage conversion of the reactions decreases with increasing generation number and increasing AA content of the copolymers.…”

“…Dendrigrafts were synthesized on the ES‐fibres according to the procedure described previously . Several consecutive reaction steps were carried out.…”

“…Dendrigrafts were synthesized on the ES-fibres according to the procedure described previously. 20,21 Several consecutive reaction steps were carried out. In the first step, the carboxylic acid groups of P(AN/AA) were activated with DCC in a mixture of THF and dioxane (50:50 v/v) at room temperature for 3 h. The mole fraction of DCC was taken in accordance with the mole fraction of AA in P(AN/AA), which was 1, 2, 5 and 10 mol%.…”

Citric acid-modified acrylic micro and nanofibers for removal of heavy metal ions from aqueous media

“…To increase the reactivity of HPAN with CA, HPAN fibers were reacted with N,N´-Dicyclohexylcarbodiimide (DCC) [17,18]. HPAN fibers were added to a flask containing a solution of DCC in THF and dioxane (50:50 v/v).…”

Dendritic Molecules on Solid Support: Solid‐Phase Synthesis and Applications

“…Synthesis of dendrigrafts of citric acid on acrylonitrile/acrylic acid copolymer solid films via repetitive DCC-induced esterification reaction were reported by Kish et al 63 Since after each coupling cycle the unreacted sites cannot be distinguished from the carboxylic ends of the units that had just been attached, it is likely that a range of dendrons of different generations (rather than monodispersed dendrons of a certain generation) populate the surface of the film.…”