Conducting polymer blends of polypyrrole with polyvinyl acetate, polystyrene, and polyvinyl chloride based toxic gas sensors

Abstract

Blends of the conducting polymer, polypyrrole (PPy), and in the insulating host polymers, polyvinyl acetate (PVAc), polystyrene (PS), and polyvinyl chloride (PVC) resin, have been prepared chemically. Threshold conductivities occur at about 5% for PPy in blends with host polymers. The characterizations of these blends were done by FTIR, UV-visible, differential scanning calorimetric (DSC), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The products of the blends have electrical conductivity comparable to PPy and mechanical properties similar to hosting polymers. The response mechanism of the conducting blends to a selection of gases and vapors was investigated using two techniques, measurement of conductance and mass changes using a four-point probe method, and a X-ray fluorescence (XRF) device, respectively. These responses of blends to toxic gases and vapors are more well explained. Prepared films were exposed to hydrogen halides (HCl, HBr, and HI), hydrogen cyanide, halogens (Cl 2 , Br 2 , and I 2 ), monochloroacetic acid (MCAA), 1-3-5 trichloromethyl benzene (TCMB), methylbenzyl bromide (MBB), bromoacetone (BA), and cyanogen bromide (CB). The changes of conductivity of polymers frequently observed are partly due to one stage in the twostage sorption, perhaps involving the swelling of the polymer, then diffusion gases into polymer chains. The swelling of polymers is a slow process, therefore, preswelled polymer films tend to decrease the response times of blends with respect to gases.

Novel electrically conductive polyurethane/montmorillonite-polypyrrole nanocomposites

“…Among ICPs, polypyrrole (PPy) is a particularly promising material because of its high electrical conductivity, chemical and environmental stability in the oxidized state, low ionization potential, electrorheological properties, electrochromic effect and relatively easy of synthesis [1][2][3][4][5][6]. In fact, PPy can be potentially used in new advanced technology areas, including electronic and optoelectronic nanodevices [7], sensors [8][9][10][11][12][13], supercapacitors [14,15], energy storage devices [1,7,16], surface coatings for corrosion protection [17], electromagnetic shielding applications [18][19][20], smart textiles [21,22] and even in medical applications [4,[23][24][25][26]. However, the poor mechanical performances and the difficult processability (insolubility and infusibility) [2,3,19,20,27,28] have hampered the use of PPy for technological applications.…”

“…One approach to possibly overcome the above limitations is blending PPy with commercial insulating polymers to produce conductive polymer blends or composites [3,11,27,[29][30][31][32][33]. Among the methods mentioned in the scientific literature, melt mixing offers the advantages of large-scale production and reduced cost which are the bases for any industrial application.…”

Interaction of carbon monoxide with PEDOT-PSS/zeolite composite: effect of Si/Al ratio of ZSM-5 zeolite

“…Conductive polymers have received increasing attention in the field of gas sensing materials [9]. The combination of conductive polymers with other materials such as metals or metaloxide nanoparticles [10][11][12], carbon nanotubes [13][14], and insulating polymers [15] have been developed and studied.…”

Improvement of the conductivity, electroactivity, and redoxability of polythiophene by electropolymerization of thiophene in the presence of catalytic amount of 1‐(2‐pyrrolyl)‐2‐(2‐thienyl) ethylene (PTE)

“…1 These polymers are used in many applications, such as batteries, 2 electrochromics, 3,4 gas separation membranes, 5 electromagnetic interference shielding, 6,7 sensors, 8,9 and metal protection against corrosion. 10,11 Electropolymerization is a commonly used technique for the synthesis of conducting polymers.…”