Properties Of Polyvinyl Alcohol Films Research Articles

Mechanical and Barrier Properties of Polyvinyl Alcohol Films Modified with Carbon Nanotubes and Zinc Oxide

A solution blending technique was employed to form a nanocomposite film of polyvinyl alcohol modified with carbon nanotube and zinc oxide (CNT/ZnO). The film was characterized using a tensile testing machine, X-ray diffraction, scanning electron microscopy, a contact angle device, and barrier property measurement. When the CNT/ZnO content was 1.2 phr, the results from mechanical property and water vapor permeation tests showed that the nanocomposite film had good tensile strength and water resistance. Moreover, CNT/ZnO improved the hydrophobicity of the film. CNT/ZnO/can improve the performance of PVA and is a good nanofiller of PVA. The results of this research might have the opportunity to be used as packaging film materials in the future.

Synthesis and structural of Cd0.5Zn0.5F2O4 nanoparticles and its influence on the structure and optical properties of polyvinyl alcohol films

This paper aims to synthesize cadmium-zinc ferrite (Cd0.5Zn0.5F2O4) nanoparticles and to fabrication of polyvinyl alcohol (PVA) films that host Cd0.5Zn0.5F2O4 nanoparticles in order to enhance structural and optical properties. Cd0.5Zn0.5F2O4 nanoparticles are prepared via sol–gel method and PVA–Cd0.5Zn0.5F2O4 films are prepared by solution casting. Characterization of Cd0.5Zn0.5F2O4 nanoparticles and the prepared nanocomposite films are investigated via X-ray diffraction (XRD), optical microscope, and UV–Vis spectrophotometry. XRD analyses are confirmed the formation of Cd0.5Zn0.5F2O4 nanoparticles and the crystal structure of polymer films are changed with the addition of Cd0.5Zn0.5F2O4 nanoparticles. The effect of Cd0.5Zn0.5F2O4 nanoparticles on the optical parameters is investigated. Urbach energy, refractive index, and extinction coefficient are increased, while the band gap decreases as the Cd0.5Zn0.5F2O4 concentration increases in the PVA matrix. Furthermore, optical dielectric constants and optical conductivity are enhanced as the Cd0.5Zn0.5F2O4 content rises in the polymer matrix.

Improving Physical Properties of Polyvinyl Alcohol Film through The Addition of Nanocellulose Prepared from Palm Oil Solid Waste

Cellulose from the palm oil solid waste (oil palm shells and stems) be isolated and used as a filler material in a biodegradable plastic, in order to improve its mechanical properties. Polyvinyl Alcohol (PVA) is a biodegradable polymer and compatible for nanocellulose fillers, where its mechanical properties can reach the same level as the conventional plastic. In this study, nanocellulose has been successfully prepared from the oil palm shells and stems with acid hydrolysis method and applied as a filler for PVA/nanocellulose film composite. The characterizations include Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC) and mechanical properties (tensile and elongation). The FTIR and DSC analysis confirm the improvement of the mechanical properties after the addition of nanocellulose, where the tensile strength reaches 14.64 kgf/mm2 with the optimal thermal ratio at 203.5°C. Nevertheless, the addition of 20% nanocellulose reduces the value of tensile strength and elongation.

The instructive role of mechanical properties of polyvinyl alcohol film in the process of YSZ tape calendering

Aqueous tape calendering offers the advantage of a simple fabrication process, inexpensive equipment, and environmental friendliness. Polyvinyl alcohol (PVA), as a polymer, is a conventional binder for aqueous tape calendering. In this innovative work, we aim to achieve a suitable process for tape calendering, by studying mechanical properties of the PVA polymer film with a series of plasticizers. The results show that the elongation at break of the PVA film reaches a maximum of 828.26%, using a triple plasticizer of glycerol, polyethylene glycol (PEG) 200, and PEG 400. With an optimized ratio of the binder to the plasticizer, a YSZ sheet with a relative density of 98% and a conductivity of 0.043 S cm−1 at 800 °C is obtained by sintering at 1400 °C, demonstrating comparable performance to those of the YSZ electrolytes by dry pressing. SEM reveals that the sintered YSZ body is dense, and has no visible open and closed pores. The mechanical properties characterization of the PVA polymer film adopted in this paper has instructive significant instruction for tape calendering and tape casting methods.

Influence of pentaerythritol on the properties of polyvinyl alcohol films for the polarizers

Pentaerythritol was used as the plasticizer to prepare PVA films through solution casting method. The interaction between pentaerythritol and PVA was studied by FTIR. The crystallinity of raw PVA and modified PVA films was characterized by X-ray diffraction. The effect of the addition of pentaerythritol on the swelling properties, mechanical properties and optical properties of PVA films were investigated. The experimental results showed that the addition of pentaerythritol destroyed the hydrogen bonding in the PVA molecule and reduced the crystallinity of PVA. As the pentaerythritol content increased, the swelling property of the PVA films was significantly improved. The addition of pentaerythritol into PVA resulted in the increase of elongation at break, as well as the decrease of tensile strength. As the amount of pentaerythritol added, the optical performance of the PVA films was improved.

Comparison of physicochemical, mechanical and antioxidant properties of polyvinyl alcohol films containing green tealeaves waste extracts and discarded balsamic vinegar

Abstract Plant origin processed food wastes like tealeaves, coffee, fruit or wine pomace can be very rich in antioxidants and antiseptics. The goal of this work is to develop antioxidant polyvinyl alcohol (PVA) packaging films using wastes generated from used green tealeaves and discarded (quality control failed) balsamic vinegar and compare their properties. Both components were separately incorporated into PVA via simple one-pot fabrication approach. Formic acid was used to extract potential antioxidants from dried waste tealeaves, simultaneously dissolving PVA. Discarded vinegar was simply added to a water solution of PVA and in both cases antioxidant films were produced by solution casting and drying. PVA films were loaded up to 50 wt.% by both waste components allowing maximum utilization of useful organics from both discarded foodstuffs. Formic acid extracted gallated catechins with very high yields (>95 %) from tealeaves waste with excess amounts of epigallocatechin gallate (EGCG). Moreover, discarded balsamic vinegar was found to be an effective plasticizer for PVA with 150 % elongation levels. Tealeaves waste exhibited better inhibitory concentration levels (IC50; 73.1 μg/ml) than discarded balsamic vinegar (1846.7 μg/mL), comparable to synthetic commercial antioxidants. They also improved oxygen barrier properties of PVA, regardless of the solvent used. These films could be potentially suitable for antioxidant food packaging applications.

Estimation of structural and mechanical properties of Cadmium Sulfide/PVA nanocomposite films

Cadmium Sulfide (CdS) nanoparticles have been synthesized by hydrothermal method, and dispersed in varying amounts by weight, in Poly Vinyl Alcohol (PVA) matrix. Subsequently, PVA/CdS nanocomposite films have been characterized and analyzed to estimate CdS nanoparticles effect on the properties of PVA films. Both mechanical and structural properties have been considered for the analysis. From the FTIR (Fourier Transform Infrared Spectroscopy) analysis it's found that stretching of C-H, CO, COC and COS were observed at different peaks that may be due to different functional groups. X-ray diffraction (XRD) results showed that the matrix contain pure nano CdS particles. The images obtained by Scanning Electron Microscopy (SEM) showed the presence of varying degree of agglomerated CdS nanoparticles distributed homogeneously in the PVA/CdS nanocomposite. Thermal properties are found using DSC (Differential Scanning Calorimetry) was used to investigate. PVA/CdS samples were tested by Universal Testing Machine (UTM) and the results indicated improvement in mechanical properties when compared with neat PVA film, viz. Young's modulus (from 33.20 to 94.30 MPa), ultimate tensile stress (from 17.03 to 27.60 MPa), toughness (from 2.18 to 17.62 MPa) and flexural strength (from 4.43 to 7.66 Mpa) with increase in the CdS content in the nanocomposite film.

Optical properties of polyvinyl alcohol film irradiated with Nd:YAG laser

Casting solution method has been used to prepare Polyvinyl alcohol (PVA) film. The prepared film has been irradiated with a laser beam of 6ns Q-switched Nd:YAG laser (Lotus II) operating at 10Hz and fourth harmonic wavelength, 266nm, at different irradiation times. Optical absorbance of the irradiated sample was studied in the wavelength region between 200 and 800nm. The absorption peak shift of 272nm towards the longer wavelengths region and the increase of absorption as the irradiation time increases, are related to the increase in crosslinking network. The fitting technique of the absorbance revealed an indirect allowed transition with optical energy gap of 4.22eV for the pristine PVA sample, and 2.85eV after 2h of laser irradiation. The index of refraction and the dielectric function showed dispersion in the studied wavelength range. The analysis of color parameters of PVA showed an observable change after laser irradiation.

Optical properties of Polyvinyl Alcohol Films doped with Fe

FeCl 3 was used as a source of Fe that added to the PVA films. PVA-Fe films wereprepared by casting method. The UV-Visible spectrophotometer used to record theabsorbance spectrum in the range of 300-900 nm. The absorbance decreased with theincreasing of Fe in the PVA films. The absorption coefficient increased with theincreasing of Fe content, while the extinction coefficient, refractive index and opticalconductivity are decreased. The optical conductivity decreased from 4 eV for PVA filmto 3.3 eV for PVA-3% Fe films.

Optical and Magnetic Properties of Polyvinyl Alcohol Films Filled with CoCl2, NiCl2, and FeCl3

Polymeric films based on polyvinyl alcohol (PVA) doped with CoCl2, NiCl2, and FeCl3 at different weight percent were prepared using the cast technique. The structural properties of these films were investigated by X-ray diffraction, UV–visible (UV-Vis) double beam scanning spectrophotometer, and vibrating sample magnetometer techniques. PVA shows crystalline nature while highly doped PVA films show amorphous nature, indicating the random distribution of the fillers within the polymeric matrix. It is found that the average of crystalline size and interplanar spacing of PVA vary with different fillers. The UV–visible absorption of the samples shows noticeable change in the band position shifted to higher wave length with the filling level. The PVA/metal chloride composites exhibit a ferromagnetic behavior with low remanent and saturation magnetization at room temperature.

Effect of hydrolysis degree and mass molecular weight on the structure and properties of PVA films

In this work, we aim to analyze the variation of structural, thermal, and dielectric properties of polyvinyl alcohol (PVA) films by varying the molecular weight (Mw) and the hydrolysis degree (HD). The XRD study revealed the improvement of the crystallinity degree by the increase of HD or the decrease of Mw. The DSC study showed the decrease of the molecular mobility with the increase of either the hydrolysis degree or the molecular weight. The dielectric measurements showed four dielectric processes attributed to electrode/sample polarization, α a-relaxation, α c-relaxation, and β-relaxation. The activation energy attributed to α a-relaxation and α c-relaxation, increase with the increase of the molecular weight Mw, and the decrease of HD. The Ac conductivity is well fitted to the universal Jonsher law in the frequency range where the electrode/sample polarization can be neglected.

Photoluminescence and electrical properties of polyvinyl alcohol films doped with CdS nanoparticles

In situ preparation of polyvinyl alcohol (PVA) films doped with cadmium sulfide (CdS) nanoparticles was conducted by gamma radiation. The films were characterized in terms of photoluminescence and electrical conductivity. The photoluminescence results indicated the existence of two emission peaks around 470 and 530 nm, which are due to electron–hole recombination of CdS nanoparticles and surface trapped emission due to the PVA capping, respectively. DC electrical conductivity (σDC) measurement in the temperature range from 303 up to 373 K reveals an increase in its value with increasing both Cd2+ ion molar concentration and irradiation dose. AC electrical conductivity (σAC) measurement over the same temperature range at an applied field frequency of 10, 100, 500 and 1000 kHz shows an increase behavior with increasing temperature, frequency, Cd2+ ion molar concentration and irradiation dose. Dielectric constant (e1) exhibits an increase with temperature, whereas it shows reduced values with increasing frequency, Cd2+ ion molar concentration and irradiation dose. Also, the dielectric loss tangent (tan δ) follows an increasing trend with increasing temperature, Cd2+ ion molar concentration and irradiation dose while it has an opposite trend with increasing frequency. The CdS/PVA nanocomposite films behavior could be explained on the basis of formation of charge-transfer complexes (CTCs) by the CdS nanoparticles doped into the PVA matrix and the role of radiation in enhancing the charge carrier mobility of such CTCs.

Physical and antibacterial properties of polyvinyl alcohol films reinforced with quaternized cellulose

ABSTRACTHydroxypropyltrimethylammonium chloride cellulose (CM) was homogeneously synthesized in a NaOH/urea aqueous solution. CM was blended in a polyvinyl alcohol (PVA) matrix to produce composite films via co‐regeneration from the alkaline solution. The PVA film and the blend films were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction measurements and scanning electron microscopy. The mechanical properties, water swelling ratio, hydrophobicity, light transmission, and antibacterial activity against Staphylococcus aureus and Escherichia coli were also evaluated. The results showed that CM could interact with PVA by hydrogen bonding and exhibit an obvious reinforcement effect. The addition of CM improved the surface roughness, hydrophobicity and water swelling ratio, especially, the antibacterial activity. However, compared with neat PVA film, the elasticity and optical transmission decreased. The increased tensile strength, powerful antibacterial activity, and medium light transmission indicate that the biocompatible blend film will become an exceptional alternative in functional bio‐material field. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43552.

Influence of cadmium sulfide nanoparticles on structural and electrical properties of polyvinyl alcohol films

Influence of cadmium sulfide nanoparticles on structural and electrical properties of polyvinyl alcohol films

Enhanced mechanical properties of polyvinyl alcohol composite films containing copper oxide nanoparticles as filler

This study has been conducted to investigate the effect of incorporating CuO nanoparticles inside PVA matrix with the aim of enhancing the mechanical properties of PVA for reinforcement purposes. Films were prepared by solution intercalation technique with 0.5, 1.0, 1.5 and 2.0 wt% CuO nanofiller content taking neat PVA as the reference for the study. Structural characterisations of the prepared nanocomposite films were carried out by FTIR, SEM and XRD techniques. Various mechanical parameters such as tensile strength, elastic modulus, flexural strength and toughness were investigated and significant enhancement in the properties of polyvinyl alcohol films containing CuO nanofillers was observed. Elastic modulus and toughness showed a linear relation with respect to nanofiller concentration at low wt%, whereas at higher wt% of CuO, the nature was observed to be non-linear. PVA-2.0 wt% CuO nanocomposite showed the highest values of flexural strength, toughness and tensile strength among all the fabricated nanocomposite films.

Influence of zinc oxide nanoparticles on structural and electrical properties of polyvinyl alcohol films

This study has been conducted with the objective of investigating the effects of zinc oxide nanoparticles on the structural and electrical properties of polyvinyl alcohol films. The fabricated nanocomposites were characterised by Fourier transform infrared spectroscopy, UV–visible (vis) spectra, X-ray diffraction and SEM techniques. UV–vis spectra showed that the addition of ZnO nanoparticles did not affect the absorbance in the visible region of nanocomposites. The SEM image showed that ZnO nanoparticles were homogeneously dispersed throughout the entire film’s polymeric matrix. The dielectric properties were found to be strongly dependent on frequency and nanofiller content. AC conductivity σac of polyvinyl alcohol/ZnO nanocomposites increased with increasing frequency. The dissipation factor tan δ also increased with nanoparticle addition and decreased with frequency. At low nanofiller concentrations, nanocomposites exhibited low dielectric values at higher frequency, thus behaving like a lossless material, making them suitable for utilisation in microwave applications.

Effect of Single and Double Stage Chemically Treated Kenaf Fibers on Mechanical Properties of Polyvinyl Alcohol Film

The physico-mechanical properties of lignocellulosic kenaf fiber reinforced polyvinyl alcohol (PVA) biocomposite films were investigated. To improve the properties of the biocomposite, kenaf fibers were chemically treated separately in a single stage (with Cr2(SO4)312(H2O)) and double stages (with CrSO4 and NaHCO3) to improve the adhesion and compatibility between the kenaf fiber and PVA matrix. PVA was reinforced with various compositions of chemically treated kenaf fiber by using a solution casting technique. Microstructural analyses and mechanical tests were subsequently conducted. Scanning electron microscopic analysis indicated that chemical treatment improved the uniformity distribution of kenaf fiber within the PVA matrix. FTIR and XRD analyses confirmed the presence of chromium on the fiber surface. The tensile strength of PVA reinforced with chemical treated kenaf fiber was found to be higher than those reinforced with untreated kenaf. The Young’s modulus, flexural strength, and flexural modulus increased with fiber loading for both untreated and treated kenaf fiber reinforced PVA films. The double stage treated kenaf fiber showed better mechanical properties and lower moisture uptake than the single stage treated kenaf fiber.

The influence of zinc oxide–cerium oxide nanoparticles on the structural characteristics and electrical properties of polyvinyl alcohol films

With the objective to investigate the influence of zinc oxide–cerium oxide (ZnO–Ce2O3) nanoparticles on the electrical properties of polyvinyl alcohol (PVA), PVA/ZnO–Ce2O3 nanocomposite films were prepared by solution intercalation method with different weight percentage viz., 0.5, 1.0, and 2.0 wt% of ZnO–Ce2O3 nanoparticles. The fabricated nanocomposites were characterized by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The effect of ZnO–Ce2O3 nanoparticles on the dielectric constant (e′), dielectric loss (e″), electric modulus (M′ and M″), ac conductivity (σ ac), and dielectric loss tangent (tan δ) over a range of frequencies at room temperature of PVA nanocomposites have been studied. FT-IR, XRD, and DSC analysis indicates the nature of ZnO–Ce2O3 nanoparticles interaction with the PVA matrix. The morphological behavior of the nanocomposites has been performed using scanning electron microscopy (SEM). The dielectric behaviors such as dielectric constant (e′) and dielectric loss (e″) increases with increase in nanoparticle concentration, but decreases with increase in frequency. But, the electric modulus (M′) increases with increase in frequency. Dielectric loss tangent (tan δ) decreases with increase in filler content at lower frequency, but at higher frequencies the tan δ increases with increase in nanoparticles content. AC conductivity (σ ac) of PVA/ZnO–Ce2O3 nanocomposites increases with increasing frequency following the universal dielectric response law.

Optical Properties of Polyvinyl Alcohol Films Modified with Silver Nanoparticles

Polyvinyl alcohol (PVA) films modified with Ag nanoparticles and orientated by single‐axial tension do not possess dichroism at light passing as well as the film that is cross‐linked under the action of bichromates and UV light. These films are double‐ray refracting and behave themselves as phase plates that transform linearly polarized incident radiation to elliptically polarized one. The film of latter type has optical properties of reflective diffuse polarizer with polarizing ability ~0.8 in the range of observation angles from 20° to 80°.

Polymeric dressing formulations containing water-soluble fullerene derivatives

The effect of small additions of water-soluble fullerene C60 derivatives on the strength properties of polyvinyl alcohol films was examined. Solutions of polyvinyl alcohol and fullerenol were tested as polymeric dressing formulations for glass-reinforced plastics based on a thermoplastic polyethylene or polyamide matrix.