PVC Polymer Research Articles

Development and investigation on PMMA–PVC blend-based solid polymer electrolytes with LiTFSI as dopant salt

PMMA–PVC polymer blend systems with LiTFSI as dopant salt were prepared by solution casting technique. Studies were then performed to explore the ionic conductivity, crystallographic structure, morphology, and thermal properties of these polymer electrolytes. XRD and SEM reveal amorphous behavior and morphologies of polymer electrolytes, respectively. Coherent length was calculated to determine the amorphousity of polymer complexes. Ionic conductivity was calculated using ac-impedance spectroscopy. DSC measurements revealed a decrease in Tg, whereas Tm and Td were enhanced. The thermal properties of polymer electrolytes were found to enhance upon addition of 30 wt% LiTFSI. Increase in thermal stability of polymer electrolytes were further confirmed through TGA studies.

Novel electrospun PAN–PVC composite fibrous membranes as polymer electrolytes for polymer lithium-ion batteries

Composite fibrous membranes based on poly(acrylonitrile)(PAN)-poly(vinyl chloride)(PVC) have been prepared by electrospinning. The fibrous membranes are made up of fibers of 850- to 1,300-nm diameters. These fibers are stacked in layers to produce a fully interconnected pore structure. Polymer electrolytes were prepared by immersing the fibrous membranes in 1 M LiClO4-PC solution for 60 min. The condition of pure PAN polymer electrolytes is jelly, which has poor mechanical performance and cannot be used. But when PVC with a good mechanical stiffener was added to PAN, the condition of composite PAN–PVC polymer electrolytes becomes free-standing. In addition, the optimum electrochemical properties have been observed for the polymer electrolyte based on PAN–PVC (8:2, w/w) to show ionic conductivity of 1.05 × 10−3 S cm−1 at 25 °C, anodic stability up to 4.9 V versus Li/Li+, and a good compatibility with lithium metal resulting in low interfacial resistance. The promising results showed that fibrous PEs based on PAN–PVC (8:2, w/w) have good mechanical stability and electrochemical properties. This shows a great potential application in polymer lithium-ion batteries.

PVC/COPPER OXIDE COMPOSITES AND THEIR EFFECT ON BACTERIAL ADHERENCE

In this work, PVC/CuO and PVC/Cu 2 O composites were prepared by melt-blending method. The results of scanning electron microscopy (SEM) – X ray energy dispersive spectroscopy (EDS) Cu-mapping showed that the composites are a hybrid of the polymer and the copper oxide particles, and these particles were distributed uniformly in the polymer matrix. The adherence of Escherichia coli ATCC 25922 on the surface of composite materials was assessed through the inventory of adhered viable cells and SEM analysis. In PVC/copper oxide composite, the number of adhered bacterial cells was reduced by almost 2 units log 10 with regard to those adhere to the pure PVC polymer. SEM images of composite materials showed a significant decrease in bacterial adherence when compared to the pure polymer. It was also found through transmission electron microscopy (TEM) images to that E. coli incubated in the presence of cuprous oxide (Cu 2 O) and cupric oxide (CuO) microparticles go through structural and morphological changes at the membrane level. Bacterial cells incubated in the presence of Cu 2 O were bacillary with blunt ends, and their size was reduced by 30% when compared to those incubated in the absence of copper oxides. The results obtained indicate that the PVC/copper oxide composites inhibit the adhesion of E. coli to their surface.

Tripmultiplet-state dynamics of manganese(III) porphyrin fabricated into PVC film

Luminescence lifetimes of anion complexes of manganese(III) porphyrins incorporated in the PVC polymer film were investigated by the time-correlated single photon counting (TCSPC) method. The tripquintet state lifetimes (tens of picoseconds) which had been measured in the solution phase were reduced to the hundreds of picoseconds regime in the polymer solid phase when the internal motions of porphyrin moieties are restricted by the PVC polymer matrix. The main effects of bulkier anion ligation on photophysical properties were the increment of effective void volume. The increase of lifetime constants in the stiff polymer matrix was largest in case of the smallest anion ligation due to the restriction of internal motion induced by local polymer structure having the smaller void volume.

Nonlinear optical properties of manganese porphyrin-incorporated PVC film

We measured thermally originated solid phase nonlinear optical properties of manganese porphyrin-incorporated PVC polymer film using CW low-power Z-scan and optical power limiting methods. The nonlinear refractive index (n2) of this porphyrin film is estimated to have a negative value of 7.2 × 10 -5 cm 2 /W at 632.8 nm and to be larger than that of ZnTPP in the Nafion film. The photodegradation effect common in the solution phase appears to be minor in this solid phase system. The large nonlinear effect is thought to limit the optical power due to the aperture effect.

Molecular and optical modifications in poly(vinyl chloride) due to N-phenylmaleimide additives and gamma irradiation

The effects of N-phenylmaleimide (NPMI) concentration and gamma dose on the molecular and optical properties of poly(vinyl chloride) (PVC) have been studied. The results reveal an improvement in the intrinsic viscosity of PVC in the presence of an organic material. The effective concentration that enhanced the intrinsic viscosity, from 1.02 to 1.28, was found to be 10 mmol NPMI per 100 g PVC. The effect of gamma irradiation on the PVC polymer stabilized with this concentration of NPMI has been studied. Samples from the 0.01 g NPMI/1 g PVC were irradiated with gamma doses in the range 5–180 kGy. It is found that irradiation in the dose range 120–180 kGy enhances the intrinsic viscosity of the samples. In addition, the transmission of these irradiated samples in the wavelength range 200–2500 nm, as well as any color changes was studied. The color intensity (Δ E) was greatly increased with the increasing gamma dose, and was accompanied by darkness with a significant increase in the yellow color component.

Chamber studies on mass-transfer of di(2-ethylhexyl)phthalate (DEHP) and di- n-butylphthalate (DnBP) from emission sources into house dust

For a number of phthalates and especially for di(2-ethylhexyl)phthalate (DEHP), surprisingly high house dust concentrations are reported in the literature. Therefore, the uptake of the most prominent compounds DEHP and di- n-butylphthalate (DnBP) from plasticized indoor materials into house dust samples of different organic content has been experimentally determined. The experiments have been performed within 45 days which is sufficient for the more volatile phthalate (DnBP) to reach equilibrium conditions. DnBP reaches considerably higher concentrations in the chamber air compared to real room measurements and, thus, also elevated dust concentrations. In contrast, the mass transfer of DEHP in the dust via the gas phase was significantly lower. However, small chamber experiments showed elevated mass transfer of DEHP in case of direct contact between emission source and sink. This aspect is experimentally determined using an plasticized PVC polymer with and without direct contact to house dust. A transfer into the dust could be observed in dependence of the initial concentration in the material. However, the results do not allow the differentiation between the two uptake mechanisms via capillary forces and contact to the material’s boundary layer. The results illustrate that the reasons for elevated DEHP concentrations in dust indoors can be traced back to direct contact of source and sink, abrasion from the source, and transport via airborne particles.

Fabrication of high density nano-pillar type phase change memory devices using flexible AAO shaped template

In this study, the high density nano-pillar type phase change memory was fabricated using duplicating nano-patterns of the anodic alumina oxide (AAO) by nanoimprint process. The high density nano-hole array of AAO template was transferred to the flexible PVC polymer template using hot embossing method. To use the flexible AAO shaped template for UV-NIL, the high density nano-pillar type Ge 2Sb 2Te 5 patterns were fabricated, and the electrical properties of the device were evaluated by conducting atomic force microscopy, connected electrical measurement system. To use the flexible AAO shaped template for UV-NIL, high density GST pattern could be fabricated even on the flexible polyimide (PI) substrate.

A novel method to develop an elastic, thin-walled, leak-proof, inflatable tracheal tube cuff

Commercially available endotracheal tube (ETT) cuffs are made of PVC polymer that shows little stretch upon inflation, resulting in a need for a cuff diameter larger than the trachea. Such cuffs form folds, which became a ready passageway for bacteria-colonized subglottic secretions. We developed an elastic and smooth balloon with no folds upon inflation.

Study of microporous PVA/PVC composite polymer membrane and it application to MnO 2 capacitors

A microporous poly(vinyl alcohol)/poly(vinyl chloride) (PVA/PVC) composite polymer membrane was successfully synthesized by a solution casting method and a preferential dissolution method. The characteristic properties of PVA/PVC composite polymer membranes were systematically studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), micro-Raman spectroscopy and AC impedance spectroscopy. The PVA/PVC composite polymer membrane shows excellent thermal property, dimensional stability, and the ionic conductivity; it is due to the addition of secondary PVC polymer fillers. The MnO 2 capacitors with the PVA/PVC composite polymer membrane with 1 M Na 2SO 4 was assembled and examined. It was found that the MnO 2 capacitor based on a microporous PVA/5 wt.%PVC composite polymer electrolyte membrane exhibited the maximum specific capacitance of 238 F g −1 and the current efficiency of 99% at 25 mV s −1 after 1000 cycle test. The result demonstrates that the novel microporous PVA/PVC composite polymer membrane is a potential candidate for use on the capacitors.

Dielectric response of PVC polymer loaded with Ba0.3Na0.7Ti0.3Nb0.7O3 ceramic powder

Dielectric response of poly(vinyl chloride), (PVC), loaded with different amount of Ba0.3Na0.7Ti0.3Nb0.7O3 (BNTN) ceramic powders was investigated in frequency range 100 Hz–1 MHz and temperature range 100–450 K. Ceramic solid solution of barium titanate and sodium niobate with composition Ba0.3Na0.7Ti0.3Nb0.7O3 was obtained from BaCO3, TiO2, Na2CO3 and Nb2O5 by conventional method. Powders were prepared by grinding of ceramics. The obtained ceramics, used to produce BNTN–PVC composites, are characterized by the relaxor behaviour with a broad peak of dielectric permittivity ε′ at T m ≈ 230 K. The microstructure of the powders was observed and the grain size was estimated using scanning electron microscope Hitachi S-4700. The EDS analysis confirms the qualitative and quantitative chemical composition of powders and ceramics. The BNTN–PVC composite samples of 0-3 connectivity were prepared from ceramic and polymer powders by hot-pressing method. The dielectric response of the composites displays features originated from the PVC polymer modified by those of BNTN ceramics. The relaxation time of the α-process of PVC obeys the Vogel–Fulcher law and decreases with increasing volume fraction of the ceramics.

Nanomaterial Modifications on Conductivity of Coal Conveyer Belt

By analyzing the macro electrical properties and the microscopic structure from SEM of nanomaterials modified mine transmission belt samples. The influences of the filling process of inorganic nano particle-filled rubber and PVC polymer on the physical properties of coal transmission belt is reviewed, as well as PTC and NTC effect on the stability of the physical properties and stability of materials. Influence of nano-materials and polymer materials for rubber and temperature changes in the plastic filled refining process. Crosslinker and major filler changes in the amount and filled plastic chain time on the conductivity of coal conveyer belt is studied. Influence of cure temperature. Cure time on the mechanical performance is studied. The microscopic mechanism of macro conductivity change of conveyer belt is discussed.

Thermal and mechanical properties of electron beam irradiated poly(vinyl chloride)/polystyrene blends

AbstractThe effect of electron beam irradiation on the thermal and mechanical properties of poly(vinyl chloride)/polystyrene (PVC/PS) blends and PVC/PS blends containing epoxidized natural rubber (ENR) was studied. The thermogravimetric analysis study showed that the thermal decomposition of the plasticized PVC individual polymer goes through two stages, whereas PS decomposes through one stage. However, the temperature of the maximum rate of reaction (Tmax) of PS is much higher than that for PVC and their blends. Meanwhile, the Tmax was found to increase with increasing PS ratios in the blend. The thermal stability of PVC/PS blends was greatly increased after electron beam irradiation in comparison with unirradiated blends. Moreover, the addition of ENR to PVC/PS increased the thermal stability. On the other hand, the mechanical properties in terms of tensile strength and elongation at break of PVC/PS blends are lower than pure PVC polymer because of the immiscibility. However, the addition of ENR to the PVC/PS (80/20) blend increased the elongation at break from 114 to 321% associated with a small effect on the tensile properties. These behaviors were supported by structure morphology studies observations, which indicate an improvement in the interfacial adhesion between the phases. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Selective recovery of PVC-free polymers from ASR polymers by ozonation and froth flotation

The present study focused on the selective recovery of poly(vinyl chloride) (PVC)-free polymers from automobile shredder residue (ASR) polymers by ozonation and froth flotation. Three different heavy ASR polymer samples were used. Appropriate alkaline washing was done as a pretreatment for the removal of the pollutants from the ASR polymer surface. The samples grinded by two different methods (two-shaft shear shredder and single-shaft rotary grinder) were compared for the behavior of PVC in the froth flotation. Ozonation with pre-washed by alkaline solution of PVC polymer in ASR has been found to significantly modify the hydrophilicity when compared to PVC polymer without pre-washing with alkaline solution. Whereas, alkaline washing did not change the surface hydrophobicity of other heavy polymers. It is found from the results that ozonation (with alkaline washing) has changed the contact angle of PVC from 80.7° to 55.7°, 82.4° to 59.1° and 82° to 59.6°, whereas little decrease of the contact angle was observed on other heavy ASR polymers. This result indicates that 93.5–96.4% PVC-free ASR polymer was successfully recovered with less than 0.1–0.2% of PVC by the froth flotation after ozonation in different ASR compositions. Ozonation with pre-washed by alkaline solution of ASR has significantly improved the PVC purity.

Suppression of dioxin emission in incineration of poly(vinyl chloride) (PVC) as hybridized with titanium dioxide (TiO2) nanoparticles

The present paper has demonstrated suppression of dioxin emission from poly(vinyl chloride) (PVC)/titanium dioxide (TiO2) nanohybrids. In our previous paper, we suggested a novel idea for the preparation of PVC/TiO2 nanohybrid through TiO2 nanoparticle-integrated hyperbranched poly(ɛ-caprolactone) (HPCL-TiO2), aiming at a breakthrough to solve the unresolved problem in the conventional PVC/TiO2 composites related to the poor dispersion of TiO2 nanoparticles in PVC polymer. The integration of TiO2 nanoparticles onto the HPCL could be successfully carried out by a dip-coating method based on the spontaneous self-assembly between TiO2 and HPCL. In this study, three kinds of hyperbranched poly(ɛ-caprolactone)s (HnPCLs) were prepared by varying the number, n, of monomeric units on the branched backbone chains. Thereby, it was possible to control the numbers of functional ends and the contents of TiO2 in the HnPCL-TiO2. The loadings of TiO2 in the HnPCL-TiO2s were found to be 4.37, 3.26, and 2.93wt% for n of 5, 10, and 20, respectively. The preparation of PVC/HnPCL-TiO2 (60/40) blends was performed through solution blending of HnPCL-TiO2 with PVC in tetrahydrofurane (THF) as solvent, and the dispersities of TiO2 in the resulting nanohybrids were investigated by field-emission scanning electron microscope (FE-SEM) equipped with energy dispersive spectroscopy (EDS). The FE-SEM/EDS results showed that TiO2 nanoparticles were dispersed well in PVC matrix, while some agglomerates of TiO2 was observed in the PVC+TiO2 sample prepared from the solution blending of PVC with the same amount of TiO2. The incineration experiments were performed by using a temperature-controllable electric furnace at 350°C under the flow of ambient air, and the exhaust gases resulting from the incineration process were collected. Prior to the identification of the components emitted in the incineration process, the GC experiments for calibration were performed on several commercial standards of dioxin and organic compounds known to be dioxin precursors. The GC results on the exhaust gases from the incineration of samples showed that the emissions of dioxin and precursors were largely suppressed with the increasing content of TiO2 in PVC/HnPCL-TiO2, i.e., the order of PVC/H5PCL-TiO2>PVC/H10PCL-TiO2>PVC/H20PCL-TiO2, as compared with those in the neat PVC/HnPCL without TiO2. Especially, the PVC/H5PCL-TiO2 with a maximum TiO2 loading of 1.6wt% showed removal efficiencies of ca. 60% up to 70% over the dioxin and dioxin precursors, which is equivalent to one and half to several times as much as the PVC+TiO2 samples prepared through the conventional route. The remarkable enhancement of the suppression of dioxin emission in the PVC/HnPCL-TiO2 might be attributed to the improvement of the degree of TiO2 dispersion in the nanohybrid.

Wetting of Nanogrooved Polymer Surfaces

Molecular dynamics simulations were used to study the wetting of nanogrooved PE and PVC polymer surfaces. The contact angles, equilibrium states, and equilibrium shapes of two nanosized water droplets were analyzed on surfaces with 1D-arranged periodic roughness of various dimensions. The composite solid-liquid contact, which is preferred in practical applications and in which a droplet rests on top of the surface asperities, was observed on the roughest PE surfaces, whereas water filled the similar but slightly deeper grooves on PVC surfaces. The transition from the wetted to composite contact regime occurred when the contact angle with a flat surface reached the value at which the apparent Wenzel and Cassie contact angles are equal. Droplets on grooved PE surfaces with the composite contact exhibited contact angles in agreement with Cassie's equation, but the increase in hydrophobicity on smoother surfaces with the wetted contact was less than expected from Wenzel's equation. The difference between the simulated and theoretical values decreased as the dimensions of the surface grooves increased. Only a slight increase or even a slight decrease in the contact angles was observed on the grooved PVC surfaces, owing to the less hydrophobic nature of the flat PVC surface. On both polymers, the nanodroplet assumed a spherical shape in the composite contact. Only minor anisotropy was observed in the wetted contact on PE surfaces, whereas even a highly anisotropic shape was seen on the grooved PVC surfaces. The contact angle in the direction of the grooves was smaller than that in the perpendicular direction, and the difference between the two angles decreased with the increasing size of the water droplet.

Enhanced Hydrophobicity of Rough Polymer Surfaces

Molecular dynamics simulations were used to study the effect of periodic roughness of PE and PVC polymer surfaces on the hydrophobicity. Pillars of different lateral dimensions and heights were derived from flat crystalline surfaces, and the results of nanoscale simulations on the structured surfaces were compared with theoretical predictions of the Wenzel and Cassie equations. Hydrophobicity increased on all rough surfaces, but the increase was greater on the structured PE surfaces because of the larger water contact angle on the flat PE surface than the corresponding PVC surface. Equally sized pillar structures on the two polymers resulted in different equilibrium wetting geometries. Composite contacts were observed on rough PE surfaces, and the contact angle increased with decreasing contact area between the solid and the liquid. Opposite results were obtained for rough PVC surfaces; the contact angle increased with the solid-liquid contact area, in agreement with Wenzel's equation. However, the composite contact was observed if the energies of the wetted and composite contacts were almost equal. Good agreement was obtained between the simulated contact angles and equilibrium droplet shapes and the theories but there were also some limitations of the nanoscale simulations.

Factors Controlling the Rate of Photodegradation in Polymers: The Effect of Temperature on the Photodegradation Quantum Yield in a PVC Polymer Containing Metal–Metal Bonds in the Polymer Chain

The effect of temperature on the degradation quantum yield of a poly(vinyl chloride) polymer with Cp2Mo2(CO)6 units incorporated into its chains was studied (Cp = cyclopentadienyl). The polymer is photochemically reactive in the absence of oxygen because the CpMo(CO)3 radicals formed by photolysis of the Mo–Mo bonds react with C–Cl bonds to form CpMo(CO)3Cl units. Quantum yields as a function of temperature were obtained for this polymer and for two control systems, Cp′2Mo2(CO)6 dispersed in PVC and Cp′2Mo2(CO)6 in hexane/CCl4 solution (Cp′ = η5-C5H4CH3). The quantum yields of the two control systems showed only slight increases with an increase in temperature. For the reaction in hexane/CCl4, this temperature dependence is attributed to the decrease in viscosity of the solution and the subsequent decrease in the radical-radical recombination efficiency. For the Cp′2Mo2(CO)6 dispersed in PVC, the small temperature dependence is attributed to an increase in free volume as the temperature increases. In contrast to these results, the temperature dependence of the quantum yield of the PVC polymer with Cp2Mo2(CO)6 units along its chains is relatively large. It is proposed that an increase in temperature facilitates the polymer chain relaxation processes (involving recoil and rotation) following photolysis of the Mo–Mo bond. The radical–radical recombination efficiency is subsequently decreased, which leads to a net increase in chain cleavage and degradation efficiency.

Dielectric behaviour and pyroelectricity in SBN70-PVC composites

Dielectric relaxation of the composites of 0–3 connectivity, made from Sr0.7Ba0.3Nb2O6 (SBN70) ceramic powder and poly(vinyl chloride) (PVC), with the volume fraction of ceramics Φ up to 0.2 was investigated in frequency range 100 Hz–1 MHz and temperature range 100–450 K. The SBN70-PVC composites samples were prepared from ceramic and polymer powders by hot-pressing method. The SBN70 ceramics was prepared by a sol-gel route. The microstructure of the powders was observed and the grain size was estimated using Hitachi S-4700 scanning electron microscope (SEM). The investigations of the pyroelectric response were performed using a modified, computer controlled Chynoweth method at room temperature a few months after poling. The SBN70 ceramics modifies the dielectric properties of the PVC polymer: (i) it increases the value of dielectric permittivity of the composites in the whole temperature range, (ii) the composite displays a maximum of the permittivity coming from dielectric anomaly of the ceramics. The addition of the ceramics weakly influences the dynamics of the polymer dielectric relaxation α described by Vogel--Fulcher model. The value of the pyroelectric coefficient p of poled composites increases with volume fraction of SBN70 ceramics. The p for composites with the Φ = 0.2 at modulation frequency of 1 Hz is about 100 µC m−2 K−1.

Functionalized polymer nanofibre membranes for protection from chemical warfarestimulants

A catalyst for the detoxification of nerve agents is synthesized fromβ-cyclodextrin(β-CD) and o-iodosobenzoic acid (IBA). Functionalized polymernanofibre membranes from PVC polymer are fabricated withβ-CD, IBA,a blend of β-CD+IBA, and the synthesized catalyst. These functionalized nanofibres are then tested for thedecontamination of paraoxon, a nerve agent stimulant, and it is observed that thestimulant gets hydrolysed. The kinetics of hydrolysis is investigated using UVspectroscopy. The rates of hydrolysis for different organophosphate hydrolyzing agentsare compared. The reactivity and amount of adsorption of these catalysts are ofhigher capacity than the conventionally used activated charcoal. A new design forprotective wear is proposed based on the functionalized nanofibre membrane.