Maya Dutta Gupta

Studies on water soluble conducting polymer: Aniline initiated polymerization of m-aminobenzene sulfonic acid

Abstract The synthesis of poly( m -aminobenzene sulfonic acid) homopolymer (PABS), by aniline initiated polymerization of m -aminobenzene sulfonic acid using ammonium persulfate oxidation has been attempted. The water soluble polymer PABS thus synthesized was characterized by IR, UV, TG-DSC, 1 H -NMR, SEM and ESR spectroscopic techniques. A co-ordinated IR and thermal analysis (TG, DSC) indicate that thermal desulfonation occurs preferentially in PABS–Na compared to PABS, commencing at 310°C and 370°C, respectively. The steric hindrance due to the large ortho substitution causes lowering of conductivity of PABS and its Na-salt which was found to be 5.4×10 −5 S/cm and 2.4×10 −6 S/cm, respectively. The ESR spectra show that the polymer to be strongly paramagnetic with a g value of 2.0013.

Synthesis and characterization of poly(2,5-dimethoxyaniline) and poly(aniline-Co-2,5-dimethoxyaniline): The processable conducting polymers

Poly(2,5-dimethoxyaniline) (PDMOA) and its copolymers with aniline (PADMOA), which exhibit remarkably improved solubility in common organic solvents, were obtained by chemical polymerization, and characterized by a host of physical techniques. The lowering of the quinoid absorption in the IR spectra and the upshifting of the N1s envelope in the XPS spectra indicate residual doping in the XPS polymers and thermal characteristic of the polymers provide evidence for hydrogen bonding, which appear to enhance the thermal stability of the homopolymer. These polymers are highly planar and conjugated, with well-developed polaronic features, shown by the XRD, ESR and UV-spectral data. The conductivity, however, is not high and apparently may be due to localization of polaronic charges at the hydrogen-bonding sites and the increased proportion of the insulating methoxy component in the polymer matrix.

Synthesis and characterization of conducting poly (1-aminonaphthalene), poly (2-aminonaphthalene) and poly (aniline-co-1-aminonaphthalene)

Poly (1&2)-aminonaphthalene and poly (aniline-co-1-aminonaphthalene) have been synthesized in high yields by chemical oxidative polymerization method. The polymers are soluble in polar solvents such as DMSO, NMP etc. In PNA-2 as head-to-tail coupling cannot occur, the electrical conductivity is lower than PNA-1. The copolymer exhibits distinct morphology, higher viscosity, characteristic exciton peak, appreciable thermal stability and electrical conductivity compared to PNA-1.

Sulfonated polybutadiene random ionomer as stabiliser for colloidal copper nanoparticles

Abstract New ionomer composites based on nanocopper particles provide a promising route to the fabrication of novel materials for advanced technology applications in the new millennium. Utilising the concept of colloid chemistry, a ‘smart’ nanoscale composite has been developed for the first time in viscoelastic sulfonated cis-1,4-polybutadiene ionomer matrix. The applicability of this approach to forming ‘smart’ surfaces on traditional thermoplastic elastomeric ionomer opens a new area to create a medium suitable for optical applications and viscoelastic composite thin film technology. The stabilised nanocopper colloid has been characterised using UV-vis, XRD and TEM techniques.

A novel synthesis of sulfonated polybutadiene ionomer by a phase‐transfer catalyst

The tetrabutylammonium bromide catalysed sulfonation of cis-1,4-polybutadiene in the presence of alkaline sodium bisulfite was successfully carried out without crosslinking. The sulfur content was analysed by XPS and the Schoniger method. The sulfonated polybutadiene was characterised by IR, 1H and 13C NMR spectroscopy. The probable reaction mechanism of a radical anion transfer is proposed. Conclusions regarding the ionomer formation are drawn by interpreting the glass transition (Tg) and reduced viscosity (ηred) data.