CHARACTERIZATION OF COATINGS PREPARED FROM PREVULCANIZED NR/POLYANILINE LATEX
Latex consisting of a NR/polyaniline (NR/PAni) blend is used in the preparation of thin elastic films. In this study, NR/PAni latex blends with different amounts of doped PAni and surfactants (sodium dodecylbenzene sulfonate [SDBS] and sodium dodecyl sulfate [SDS]) were prepared through prevulcanization. The films were prepared from prevulcanized latexes by casting in a petri dish or with the spin coating method. The conditions suitable for prevulcanization were investigated. The effect of doped PAni amounts and the surfactants SDBS and SDS on the mechanical, electrical conductivity, and physico-chemical surface properties and morphologies of NR/PAni films were characterized. The results indicated that PAni doped with dodecylbenzene sulfonic acid (DBSA) was well dispersed in NR latex in the presence of 0.01 mol/w% of SDBS. The highest amount of doped PAni that was dispersed was 17 w/w%. The properties of the blend of NR and DBSA-doped PAni were superior to those of the other blends. The compatibility between SDBS and DBSA was the dominant factor in improving the properties of the film prepared from the prevulcanized NR/PAni latex blend.ABSTRACT

Chemical structure of (a) SDS, (b) SDBS, and (c) DBSA.

Change in structure of PAni in the presence of H+.

Contact angle measurement.

Stress–strain curve of the samples: (a) PAni.HCl/SDS, (b) NR/PAni.HCl/SDBS, (c) NR/PAni.DBSA/SDS, (d) NR/PAni.DBSA/SDBS, and (e) NR.

A drop of water on surface of film sample: (a) NR, (b) NR/PAni.HCl/SDS, (c) NR/PAni.HCl/SDBS, (d) NR/PAni.DBSA/SDS, and (e) NR/PAni.DBSA/SDBS.

SEM image of sample surface (magnification ×1000): (a) NR, (b) NR/PAni.HCl/SDS, (c) NR/PAni.HCl/SDBS, (d) NR/PAni.DBSA/SDS, and (e) NR/PAni.DBSA/SDBS.

SEM of cracked surface (magnification ×500): (a) NR, (b) NR/PAni.HCl/SDS, and (c) NR/PAni.DBSA/SDBS.
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