Chemical and electrochemical synthesis of conducting graft copolymer of vinyl acetate with pyrrole and studies of its gas and vapor sensing

Copolymers in general exhibit physical and mechanical properties far different from those of homopolymers and different from those of blends of the same individual homopolymers. Pyrrole (Py) 3 was grafted onto a poly(vinyl acetate) (PVAc) backbone that contained the Py moiety within via chemical and electrochemical oxidative polymerization. Graft copolymer 4 was soluble with low Py amounts but became rapidly insoluble with increasing Py content due to the formation of long Py sequences. The maximum conductivity of films cast from the reaction mixture was 8.3 × 10−3 S/cm. The product 4 was characterized and studied in detail using elemental analysis, ATR, 1H-NMR, UV-visibility, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Gas sensors based on conducting polymers that exhibit electrical conducting properties can be used as specific toxic gas and vapor detectors. We report here effects of conductance and mass changes onto a graft copolymer 4 after exposure to hydrogen halides, hydrogen cyanide, 1-3-5 trichloromethyl benzene (TCMB), methylbenzyl bromide (MBB), bromobenzyl cyanide (BBC), cyanogen chloride (CC), and cyanogen bromide (CB), using two techniques: a four-point probe method and a X-ray fluorescence (XRF) device, respectively. Increasing of ratio polypyrrole (PPy) in the graft copolymer 4 increase the sensing properties of this copolymer and decrease the solubility of it. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 40–48, 2003

[1]  Ş. Süzer,et al.  A conducting composite of polypyrrole I. Synthesis and characterization , 1994 .

[2]  G. Wnek,et al.  Electrically conductive polymer composites: polymerization of acetylene in polyethylene , 1982 .

[3]  S. Hosseini,et al.  CHEMICAL AND ELECTROCHEMICAL SYNTHESIS OF HOMOPOLYMER AND COPOLYMERS OF 3-METHOXYETHOXYTHIOPHENE WITH ANILINE, THIOPHENE AND PYRROLE FOR STUDIES OF THEIR GAS AND VAPOUR SENSING , 2001 .

[4]  B. Tieke,et al.  Conducting polypyrrole-polyimide composite films , 1990 .

[5]  B. François,et al.  Polystyrene-polythiophene block copolymers (PS-PT) synthesis, characterization and doping , 1993 .

[6]  R. Bittihn,et al.  Polypyrrole as an electrode material for secondary lithium cells , 1987 .

[7]  F. Bates,et al.  Soluble polyacetylene graft copolymers , 1983 .

[8]  F. Bates,et al.  Synthesis of polyacetylene block/graft copolymers , 1984 .

[9]  B. Müller,et al.  Polymer materials in biosensors , 2005, Naturwissenschaften.

[10]  S. Hosseini,et al.  Preparation and characterization of polyaniline blends with polyvinyl acetate, polystyrene and polyvinyl chloride for toxic gas sensors , 2001 .

[11]  S. Hosseini,et al.  Synthesis of conducting polypyrrole and polycarbazole containing hydroxamic acid groups , 1995 .

[12]  B. Zinger,et al.  Electrically conducting polyethylene/polypyrrole films , 1991 .

[13]  Levent Toppare,et al.  Conducting polymer blends: polythiophene and polypyrrole blends with polystyrene and poly(bisphenol A carbonate) , 1990 .

[14]  L. Toppare,et al.  Electrically conductive poly(methyl methacrylate-g-pyrrole) via chemical oxidative polymerization , 1993 .

[15]  X. Bi,et al.  Electrically conductive blocked copolymer of polyaniline and poly(p-phenylene-terephthalamide) , 1991 .

[16]  B. François,et al.  Synthesis of soluble polystyrene-graft-polythiophene comblike copolymers : a new precursor for polythiophene film preparation , 1991 .