Preparing Poly Vinyl Chloride Research Articles

A technical approach toward pre-crack generation and its effect on the fracture behavior of polymeric materials

Regarding the urgent need for a proper pre-crack generation method in polymeric materials, this study addressed the design and fabrication of a broaching machining apparatus. The performance of this device was examined by preparing polyvinyl chloride (PVC) samples with high sensitivity to the crack-tip radius. Pre-cracks generated by broaching and slotting and then examined by SEM analysis. The fracture parameters were determined by the essential work of fracture (EWF) method. Studies indicated that the energy required for crack growth was on average 24 % lower in the broached samples, suggesting a higher stress concentration in the crack-tip by the broaching approach. The numerical analysis also revealed the more coincidence of the modeled energy values with the broaching method results, further highlighting the higher resemblance of the cracks made by this method to the ideal cracks. Interestingly, the radius of the plastic region in the slotting method was three times larger than in the broaching method, indicating the sharper tip of the pre-cracks in the broaching method. The application of the broaching method for pre-crack generation can lead to more accurate results in the mechanical fracture tests.

Toughening action in marble tailings/PVC composite plates: Rheological and mechanical properties

Herein, marble tailings (MTs) were used as mineral filler to prepare polyvinyl chloride (PVC) based composite plates. In order to improve the toughness of MTs/PVC composites, chlorinated polyethylene (CPE), methyl methacrylate butadiene styrene (MBS), ethylene–vinyl acetate copolymer (EVA), and polyolefin elastomer (POE) were adopted to investigate the toughening effects on the performance of MTs/PVC composites. The results show that incorporation of tougheners in MTs/PVC composite enhances restraint on the movement of PVC molecular chain segments, leading to the decrease of energy storage modulus and loss factor. Although these four tougheners decrease tensile strength and flexural properties of MTs/PVC composite plates, they significantly increase notched impact strength. In particular, the impact strength of MTs/PVC composite is improved by nearly 179% via using CPE toughener. Taken together, CPE not only presents the relatively most excellent rheological properties for MTs/PVC composites, but also increases toughness to the maximum extent without significantly reducing the tensile strength and flexural properties of MTs/PVC composites. Hence, a pilot testing was carried out to produce CPE-MTs/PVC composite hollow flooring. This work points out an effective resource utilization direction for the marble tailings, and it provides a reference for industrial application of MTs/PVC composite in construction and building engineering.

Study of the preparation and properties of polyvinyl chloride/nitrocellulose polymer blends

AbstractIn this study, we prepared Polyvinyl chloride (PVC)/Nitrocellulose (NC) polymer blend by the solution casting technique. The structural properties and decreased interplanar spacing and crystalline nature of the PVC/NC blends were confirmed by an XRD technique. Basic chemical fingerprint regions of PVC/NC blends were confirmed by the Fourier transform IR method. Optical properties correlated with a decreased direct and indirect bandgap energy of PVC/NC were estimated using UV–visible spectra. They exhibited a shift in the absorption spectra towards the longer wavelength region due to process of charge transfer in the blend system. An increased microporous nature of the blends was demonstrated by SEM. Based on the Maxwell–Wagner model the dielectric constant and relative loss were found to have a maximum in the low frequency region which may be contributed by the polar nature of NC. We confirmed the hydrophilic nature of the PVC/NC blends due to the presence of hydroxyl groups by the goniometer technique. The thermophysical properties of the blends were measured by Lee's disc method. NC loading in the blend system increased the thermal conductivity from 0.12 to 0.18 W/(m.K). The Shore A softness test of the blends exhibited an 18% increase. We quantified structure, bandgap, morphology, and dielectric, surface and thermal properties as a function of NC blending. This new emerging blend may be a remedy for various engineering applications. © 2022 Society of Industrial Chemistry.

High-value utilisation of ceramic waste powder in PVC-based composite and basalt fibre reinforcement effect on its performance

Herein, ceramic waste (CW) powder and basalt fibre (BF) were used as inorganic filler and reinforcement, respectively, to prepare polyvinyl chloride (PVC)-based composites. The influence of the CW content on the rheological and mechanical properties of PVC-based composites was studied to attain a proper CW filling content. Besides, the effects of BF addition on the mechanical properties, water resistance, thermal conductivity and thermal stability of the BF/CW/PVC composites were investigated. The results show that although plasticising time is prolonged as the CW filling content increases, the CW/PVC composites still have good processability under high-filling content of 50 wt% CW. The addition of 10 wt% BF improves the mechanical properties of the CW/PVC composite. The BF/CW/PVC composites have good water resistance and thermal insulation performances. The CW filling powder and BF significantly improve the thermal stability and enhance the deformation resistance and storage modulus of the composites. This work provides a high-value utilisation method for recycling CW.

Synthesis and application of high-stability bio-based plasticizer derived from ricinoleic acid

As one of the most widely used plasticizers in the market, phthalate plasticizers have been banned in European countries and regions due to their poor migration and derived from petroleum-based raw materials. Therefore, using clean and renewable resources to produce high-stability bio-based environmentally friendly plasticizers is an urgent need currently. In this work, a new type of high-stability bio-based plasticizer was obtained by a four-step reaction with ricinoleic acid as main raw material, and its structure was characterized and identified by FT-IR and 1H NMR. Subsequently, ricinoleate plasticizer, commercially available dioctyl phthalate (DOP), and bis(2-ethylhexyl) adipate (DOA) were added to prepare polyvinyl chloride (PVC) films for performance comparison. According to the TG results, the Ti (initial degradation temperature) of PVC films plasticized with ricinoleate plasticized was 40 ℃ higher than that of DOA and DOP. In addition, the tensile results showed that the ricinoleate could be used as a substitute for DOA, indicating its excellent plasticizing efficiency and mechanical properties. More importantly, ricinoleate plasticized PVC exhibited the ranking migration stability in various environments, lower glass transition temperature in DMA analysis. All the results demonstrated that compared with DOA and DOP, the ricinoleate has a better comprehensive performance, which provided a new way for the rational use of renewable resources to prepare environmentally friendly plasticizers.

Preparation and characterization of plasticized polyvinyl chloride composite film based on photochromic intelligent cooling

AbstractIndoor temperature adjustment to maintain a relatively comfortable living environment has resulted in different cooling strategies. Often, these strategies are energy consuming as well as energy wasting because of the complex and changing environment. Materials development to achieve intelligent adjustment of indoor temperature through efficient and energy‐saving methods is essential. Here, we present a strategy to prepare polyvinyl chloride (PVC)/photochromic powders cooling films. By adding different colors of photochromic powders to PVC substrate and utilizing their properties of changing color and light transmittance according to sunlight intensity to achieve the intelligent cooling effect. The indoor sunlight simulation test indicates that the PVC/red photochromic powders composite film possesses the best cooling performance under ultraviolet (UV) irradiation, and the maximum cooling range is about 10°C compared with the control sample, meanwhile the maximum cooling effect is only 2–3°C without UV irradiation. The PVC/red photochromic powders composite film also shows the best cooling effect (6°C) in the outdoor solar irradiation test with strong sunlight, and all films did not exhibit an obvious cooling effect under weak sunlight. Meanwhile, PVC/photochromic powders composite films also solve the shortcoming of the single color of traditional cooling films, which can better meet the demand of people for color diversity. In addition, the stable mechanical properties of PVC/photochromic powders composite films also give it great application value. Therefore, PVC/photochromic powders composite films can provide a promising energy‐saving solution for future intelligent adjustment of indoor temperature.

Effect of non-annealed and annealed ZnO on the optical properties of PVC/ZnO nanocomposite films

The goal of this study was to investigate the optical properties of the prepared polyvinyl chloride (PVC)/zinc oxide (ZnO) nanocomposite films. The PVC/ZnO nanocomposite films consist of the addition of different concentrations with both non-annealed ZnO nanoparticles and ZnO nanoparticles annealed at temperature of 700°C. The PVC/ZnO nanocomposite films by weight concentrations of (0 wt.%, 2.5 wt.%, 5 wt.% and 10 wt.%) have been prepared by the casting method. The optical absorbance and transmittance values of the composites films were measured in the wavelength range between (250 to 1100 nm) at room temperature by using the UV-1800 Shimadzu spectrophotometer. The optical properties (absorption coefficient, dielectric constant, refractive index, and optical conductivity) have been investigated by the ultraviolet (UV) spectrophotometer. The optical parameters (direct optical energy gap, excitation energy for electronic transitions, the dispersion energy, static refractive index, static dielectric constant, optical oscillator strengths, the moments of optical spectrum, linear optical susceptibility, third-order nonlinear optical susceptibility, nonlinear refractive index, high-frequency dielectric constant, the carrier concentration to the effective mass ratio, the long wavelength refractive index and the plasma frequency) were calculated. The results showed that the optical properties behavior of the PVC/ZnO nanocomposite films was found to be dependent on the ZnO concentration, and photon wavelength. In addition, the results of the study show that the optical parameters can be influenced by alter the concentration of the nonannealed and annealed a ZnO nanoparticle in the PVC polymer matrix.

Preparation of a monodisperse poly (N-phenylmaleimide–acrylonitrile–styrene) structural nanolatex for heat-resistant modification of PVC

A monodisperse poly ( N-phenylmaleimide–acrylonitrile–styrene) (PNAS) nanolatex was synthesized via seed microemulsion polymerization. The obtained PNAS nanolatex was then directly used as an organic nanofiller to prepare polyvinyl chloride (PVC)/PNAS hybrid composite through water blending and melt compounding. The characteristics of PNAS nanolatex were analyzed by Fourier transform infrared (FTIR) spectrometer, elemental analysis, scanning electron microscope, transmission electron microscope (TEM), dynamic laser lighting scattering (DLS), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). FTIR and elemental analysis confirmed the formation of PNAS copolymer with high monomers conversion; meanwhile, for the PNAS nanoparticles, the morphology of a well-defined core–shell spherical structure with average diameter ranging from 156 nm to 249 nm was observed. DSC analysis and TGA indicated that both polymers had excellent compatibility, and the corresponding heat resistance of PVC was greatly improved with the addition of PNAS. When PNAS loading was 50 wt%, the glass transition temperature value of PVC/PNAS hybrid composite was increased by 22.4°C, compared with that of pristine PVC. The mechanical properties of the PVC composite were also enhanced with the addition of PNAS.

Highly Selective Lead(II) Coated Graphite Sensor Based on 4,13-Didecyl-1,7,10,16-tetraoxa-4,13- diazacyclooctadecane as a Neutral Ionophore

4,13-Didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) has been explored as a neutral ionophore for preparing polyvinyl chloride (PVC)-based membrane sensor selective to lead(II). The optimized membrane incorporating kryptofix22DD as the active material, nitrobenzene as plasticizer and sodium tetraphenylborate as an anion excluder and membrane modifier in PVC (in the weight ratio of 5.0: 63.0: 2.0: 30.0, respectively) was directly coated on the surface of graphite rod. The sensor exhibits a Nernstian slope (29.4 mV/decade) in the concentration range of 1.0 × 10–5 to 1.0 × 10–1 M Pb2+. The detection limit of the sensor is 6.5 × 10–6 M. The proposed sensor has a fast response time (~10 s), a satisfactory reproducibility and relatively long lifetime. The electrode shows high selectivity toward Pb2+ ion in comparison to other common cations. The proposed sensor is suitable for use in aqueous solutions in a wide pH range of 2.0–10.0. It was used as an indicator electrode for the end point detection in the potentiometric titration of Pb2+ ion with ethylenediaminetetraacetic acid (EDTA) and sodium iodide (NaI) solutions. The proposed sensor was successfully applied for the recovery of Pb2+ ions spiked in real water samples.

Síntesis in‐situ, caracterización, evaluación antibacterial y nanotoxicológica de cueros sintéticos de cloruro de polivinilo conteniendo nanopartículas de cobre (PVC/NPsCU 0 )

Agentes capaces de transmitir enfermedades como las bacterias, virus y hongos son los principales causantes de las infecciones intrahospitalarias (IIH) en el mundo, esto ha motivado el desarrollo de los Nuevos Materiales basados en la Nanotecnología, donde en una rama de este se sintetizan nanocompósitos antibacteriales del tipo: Polímero/Metal Antibacterial, sintetizando superficies con gran actividad inhibidora de bacterias. En el presente trabajo, se han generado nanocompósitos poliméricos antibacteriales, preparando el Policloruro de Vinilo (PVC) de resina en emulsión como plastisol y sintetizando nanopartículas de Cobre dentro de la matriz polimérica (in‐situ). La descripción de la metodología se da con la síntesis de un precursor de Cobre para posterior dispersión mediante pulsos ultrasónicos, posterior estabilización y mezclado con los aditivos del PVC para posterior reducción química durante el gelificado de los plastisoles. El análisis espectral de los laminados de PVC/NPsCu0 por medio de Fluorescencia de Rayos X en Energía Dispersiva (FRX‐ED), utilizando el software específico PyMca 4.7.4, revelan que la importancia del tiempo de gelificación del PVC guarda relación con el grado de reducción del Ácido Ascórbico (AA) sobre el Cu2+. Por otro lado, resultados del análisis por Espectroscopia Electrónica de Barrido (MEB) revelan que las dimensiones de las NPsCu0 varían en un rango de 50 a 250 nm. Los patrones de difracción de Rayos X (DR‐X) evidencian la parcial cristalización polimérica del PVC y la presencia de Cu0. Se confirmó la actividad antibacteriana de los laminados de PVC/NPsCu0 por el método de difusión de disco sobre Eschericcia coli O157:H7; el halo de inhibición promedio resultó ser de 9,7 mm que implica un significativo efecto bactericida sobre la cepa mencionada. La viabilidad del desarrollo de estos nanocompósitos poliméricos se estudió por medio de un ensayo nanotoxicológico mediante el análisis citotóxico de los nanocompósitos de PVC/NPsCu0 en células de sangre periférica humana, concluyendo que dicho efecto citotóxico sobre células sanas es menor al 8%. La viabilidad del desarrollo de estos nanocompósitos poliméricos se estudió por medio de un ensayo nanotoxicológico mediante el análisis citotóxico de los nanocompósitos de PVC/NPsCu0 en células de sangre periférica humana, concluyendo que dicho efecto citotóxico sobre células sanas es menor al 8%.

Dielectric relaxation of PVC/PMMA/NiO blends as a function of DC bias

We have prepared poly vinyl chloride (PVC)/poly-methyl methacrylate (PMMA) blend with loading of Nickel oxide (NiO) by solution cast technique. X-ray diffraction reveals the interaction between NiO, PVC and PMMA in the blend form. The weak interaction between PVC, PMMA and NiO was confirmed by Fourier transform infrared spectroscopy. The miscibility of PVC and PMMA has been confirmed by differential scanning calorimetry. The results demonstrate that the 2 wt% NiO loaded PVC/PMMA blend exhibits lowest crystallinity which leads to better NiO dispersion, also observed by atomic force microscopy and scanning electron microscopy. The performance of electrical properties were evaluated under wide band of frequency (10–107 Hz) as a function of DC bias voltage (0–25 V). The dielectric property was characterized via electrical modulus formalism. The present blend systems show good dielectric property as well as considerable conductivity which differs by frequency and DC bias. The variation of AC conductivity as a function of frequency and DC bias shows plateau shape at higher frequency which obeys Jonscher’s power law. It demonstrates that the AC electrical conductivity is directly proportional to the applied DC bias potential. It may be developed for electrolyte application.

Evaluation of Phenylephrine Stability in Polyvinyl Chloride Bags

Phenylephrine hydrochloride (HCl) is commonly used to maintain adequate blood pressure during shock and shocklike states. Phenylephrine is prepared in concentrated stock vials that require further dilution prior to administration. This study evaluated the physical and chemical stability of phenylephrine in extemporaneously prepared polyvinyl chloride (PVC) bags. Phenylephrine HCl 10 mg/mL solution was diluted with 0.9% sodium chloride for injection to final concentrations of 200 µg/mL and 400 µg/mL and stored at room temperature (23°C-25°C) exposed to fluorescent light. Stability of phenylephrine HCl was evaluated by high-performance liquid chromatography on days 0, 7, 14, 21, 30, 45, and 60. Phenylephrine HCl 200 and 400 µg/mL solutions in PVC bags were physically stable during the entire 60-day study period. Phenylephrine HCl retained > 95% of the original concentration. Phenylephrine HCl diluted to 200 or 400 µg/mL with 0.9% sodium chloride for injection is both physically and chemically stable for a period of 60 days with ≤5% degradation when stored at room temperature and exposed to fluorescent lighting.

A Reactive Blending Method for Preparation of Polyvinyl Chloride/Thermosetting Polyurethane Blends

An attempt was made to prepare polyvinyl chloride (PVC)/thermosetting polyurethane (PU) blends via direct formation of the thermosetting minor phase from its reactants during blending into PVC. Chemorheological approaches were employed in order to investigate the formation reaction of PU. The results of chemorheological analyses were utilized to adjust appropriate reactive blending temperature. PVC/PU reactive blending process was carried out in a laboratory internal mixer. PVC and PU reactive mixture were fed into the internal mixer using two different feed orders. In the first method, porous particles of PVC and liquid mixture of PU monomers were premixed in a high-speed mixer at ambient temperature. The blending was then followed by processing the prepared paste in the preheated internal mixer. In the second method, PVC was loaded into the internal mixer. Afterward, PU reactive compound was introduced into the PVC after torque equilibrium. For both feed orders, the PU content of blends and rotor speed were among parameters studied. The mechanical properties of PVC/PU blends prepared by reactive blending and pure PVC showed that incorporation of PU elastomer into PVC through the proposed reactive blending technique resulted in an increase in the elongation at break and toughness of the brittle PVC.

Ni(II)-selective ion sensors of salen type Schiff base chelates

The two nickel chelates of Schiff bases, N-(2-hydroxybenzyl)- N′-(2-hydroxybenzylidene)ethylenediamine Ni(II) ( I) and N-(2-hydroxybenzylidene)- N′-(2-picolyl)ethylenediamine Ni(II) ( II), have been synthesized and explored as a neutral ionophores for preparing polyvinyl chloride based membrane sensors selective to Nickel(II). The addition of sodium tetraphenylborate and various plasticizers, viz., DOS, TEHP, DEP and CN has been found to substantially improve the performance of the sensors. The best performance was obtained with the sensor having membrane of chelate ( II) with composition (w/w) chelate (1%):PVC (33%):CN (65.5%):NaTPB (0.5%). This sensor exhibits Nernstian response in the concentration range 3.2 × 10 −6 to 5.0 × 10 −2 M Ni(II), performs satisfactorily over wide pH range of (2.2–5.9) with a fast response time (∼10 s). The sensor was also found to work satisfactorily in partially non-aqueous media up to 25% (v/v) content of acetone, methanol or ethanol and could be used over a period of 4 months. The response of the sensor was highly selective to Ni 2+ over a large number of cations and it could therefore be used for Ni 2+ estimation in the presence of a number of interfering ions. The sensor could be used successfully for the estimation of nickel at trace level in biological and environmental samples.