Silver‐Doped Zinc Oxide as a Nanofiller for Development of Poly(vinyl alcohol)/Poly(vinyl pyrrolidone) Blend Nanocomposites

Vinyl Additive Technology

Greeshma

Parvathi

et al. 2019

Self Cite

The main aim of this study is to investigate the effect of silver-doped zinc oxide (Ag-ZnO) loading on the structural, morphological, thermal and electrical properties, and gas sensing behavior of polypyrrole (PPy)/phenothiazine (PTZ)-blend nanocomposites. The composites are characterized by FTIR, XRD, SEM, TEM, DSC, TGA, and impedance studies. FTIR spectra exhibit the presence of Ag-ZnO in the PPy/PTZ blend. XRD analysis shows that the semicrystalline behavior of the polymer blend is greatly enhanced by the addition of Ag-doped ZnO particles. Uniform dispersion of nanoparticles in the polymer is obtained from SEM analysis. The TEM images confirm the presence of spherically shaped nanoparticles in PPy/PTZ blend with a size of 10-25 nm. The DSC measurement indicates that the glass transition temperature of PPy/PTZ blend was significantly improved in the presence of Ag-doped ZnO nanoparticles. The thermal decomposition temperature of nanocomposite obtained from TGA shows an increase with increase in the content of Ag-ZnO particles. The incorporation of Ag-doped ZnO nanoparticles to PPy/PTZ blend exhibit increase in the AC conductivity and dielectric properties of the nanocomposite, due to the pilling of charges at the extended interface of the composite system. The DC conductivity of the nanocomposite increases with the loading of nanoparticles. The ammonia gas sensing performance of PPy/PTZ/Ag-ZnO nanocomposite is analyzed, and the result shows that the fabricated blend composite can be used as a promising candidate for the easy access of gas molecules. Intensity (counts) FIG. 2. XRD patterns of Ag-doped ZnO, PPy/PTZ blend with different contents of Ag-doped ZnO. PPy-PTZ PPy-PTZ/ 5 wt % Ag-ZnO PPy-PTZ/ 7 wt % Ag-ZnO PPy-PTZ/ 10 wt % Ag-ZnO PPy-PTZ/ 15 wt % Ag-ZnO Tan Log frequency (Hz) FIG. 9. Dielectric loss tangent versus frequency plots for PPy/PTZ blend with Ag-doped ZnO nanoparticles. [Color figure can be viewed at wileyonlinelibrary.com]

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Structural, electrical, thermal, and gas sensing properties of new conductive blend nanocomposites based on polypyrrole/phenothiazine/silver‐doped zinc oxide

Vinyl Additive Technology

Greeshma

Parvathi

et al. 2019

Self Cite

“…Another sharp peak at 1651 cm 21 was attributed to the stretching vibrations of C@C and the methyl groups of the PVA/PVP blend. 22,23 The characteristic stretching of PVP was observed at 1289 cm 21 . The FTIR spectrum of sericin powder exhibited a broad band at 3455 cm 21 ; this was related to the NH group of sericin.…”

Section: Optical Propertiesmentioning

confidence: 98%

Preparation, characterization, electrical and antibacterial properties of sericin/poly(vinyl alcohol)/poly(vinyl pyrrolidone) composites

J of Applied Polymer Sci

Athira

Jayakrishnan

et al. 2016

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In this study, we focused on the fabrication of poly(vinyl alcohol) (PVA)/poly(vinyl pyrrolidone) (PVP)/sericin composites via a simple solution-blending method. The composites were characterized by Fourier transform infrared (FTIR) spectroscopy, UV spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry, thermogravimetric analysis (TGA), and measurements of the conductivity, tensile strength, and antibacterial activity against Staphylococcus aureus. The results of FTIR and UV spectroscopy implied the occurrence of hydrogen bonding between sericin and the PVA/PVP blend. The structure and morphology, studied by XRD and SEM, revealed that the sericin particles were well dispersed and arranged in an orderly fashion in the blend. The glass-transition temperature (T g ) of the composite was higher than that of the pure blend, and the T g value shifted toward higher temperatures when the volume fraction of sericin increased. TGA indicated that sericin retarded the thermal degradation; this depended on the filler concentration. The mechanical and electrical properties, such as the tensile strength, alternating-current electrical conductivity, dielectric constant, and dielectric loss of the composites, were higher than those of the pure blend, and these properties were enhanced when the concentration of sericin was increased up to 10 wt % filler content, whereas the elongation at break of the composite decreased with the addition of sericin particles. The antibacterial properties of the composite showed that sericin had a significant inhibitory effect against S.

“…The higher mechanical strength of Cl‐NBR is due to the stereo‐specific addition of dichlorocarbene unit to the double bond of the macromolecular chain of NBR which induces a strain‐induced crystallization to Cl‐NBR. Moreover, the dipolar interaction induces effective orientation of molecular chains of the elastomeric matrix which result in better stress transfer through the rubber and thus the improved tensile and tear properties . The decrease in mechanical properties of Cl‐NBR beyond 22 wt% Cl may be due to the steric hindrance and the loss of strain induced crystallization at a higher level of chlorination.…”

Section: Resultsmentioning

confidence: 97%

Synthesis, characterization, processability, mechanical properties, flame retardant, and oil resistance of chlorinated acrylonitrile butadiene rubber

Nihmath

Polymers for Advanced Techs

2018

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Novel chlorinated acrylonitrile butadiene rubber (Cl-NBR) was prepared from NBR by the alkaline hydrolysis of chloroform by using phase-transfer catalysis. The formation of Cl-NBR was monitored by 1 H-NMR, UV-Vis, and Fourier transform infrared spectroscopic techniques. The percentage of chlorine attached to the rubber chain was estimated by Volhard method. The effect of polar groups on the structural and thermal properties of Cl-NBR was analyzed by scanning electron microscopy, X-ray diffraction analysis, differential scanning calorimetry, and thermogravimetric analysis studies. The flame retardant, oil resistance, cure behavior, and mechanical properties of chlorinated elastomer were also analyzed. The proton NMR revealed the attachment of chlorine in the backbone of NBR with new chemical shift values. The C-Cl stretching of chlorinated NBR was confirmed from Fourier transform infrared. The UV spectrum also supported the formation of chlorinated unit in the NBR chain through the shifts and broadening of absorption peaks. The X-ray diffraction analysis pattern indicated a decrease in the amorphous domain of NBR with an increase in the level of chemical modification. The increased glass transition temperature obtained from differential scanning calorimetry confirms the increased molecular rigidity of the chlorinated NBR and thermal transitions increased with increase in the level of chemical modification. The thermal stability of Cl-NBR decreased with an increase in chlorine content. The flame and oil resistance of Cl-NBR was greatly higher than pure NBR due to the increased polarity of modified rubber. The superior tensile strength of Cl-NBR (4 times higher than pure NBR) and higher oil resistance find applications in pump diaphragms, aircraft hoses, oil-lined tubing, and gaskets materials with the excellent flame resistant property.