Polyvinyl Chloride Coatings Research Articles

Thermodynamic Properties of Aggregate Coated by Different Types of Waste Plastic: Adhesion and Moisture Resistance of Asphalt-Aggregate Systems

The utilization of acidic aggregates in hot-mix asphalt (HMA) is often inevitable due to the limited supply of locally available aggregates, posing a potential threat of moisture damage to asphalt pavements. In this regard, the use of urban waste plastic to coat the low-quality aggregates is a promising way to improve the moisture resistance. This study fundamentally evaluated the compatibility between asphalt and plastic-coated aggregate by measuring surface energy, and for the first time compared the effects of different types of waste plastic including high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polypropylene (PP). The plastic-coating significantly altered the chemistry of aggregate surface by increasing the nonpolar components and reducing the polar components. Such changes remarkably increased the dry adhesion energy between asphalt and aggregate and enhanced the wettability of aggregate. For the acidic aggregates, the polymeric treatment could decrease the value of wet adhesive, which indicated the debonding tendency in the presence of water was reduced. Finally, the energy ratios of the asphalt-aggregate combinations significantly increased by the surface pretreatment, which proved the effect of waste plastic coating on improving the moisture damage resistance of asphalt mixtures. By comparison, the HDPE coating was the most effective way to enhance the compatibility with asphalt, followed by PP and LDPE coatings. The PVC and PET coatings were investigated as the least effective way. This study cannot only contribute to the potential large-scale utilization of waste plastic but also remove the obstacles of using large quantities of acidic natural aggregate in asphalt pavements.

A molecular dynamics study of adhesion of polyvinyl-chloride coatings to the aluminum surface

Metal polymer interaction are difficult to measure experimentally, hence MD simulations are helpful in such problems to provide the vital information. Polyvinyl chloride is widely used in engineering applications due to its chemical and thermal stability and its barrier properties due to the C-Cl polar bond. Aluminum is also widely used in engineering structures as well as food and pharmaceutical packaging. Hence interaction or bonding between PVC and Al2O3 is studied using MD simulations and interaction energy is calculated at different temperature to check the influence of temperature on adhesion between the two. The higher the absolute magnitude of interaction energy, the stronger the adhesion or bonding between metal and polymer. It was revealed that for the case of PVC coating on Al2O3 the adhesion energy increases as temperature rises.

A novel thin film composite forward osmosis membrane using bio-inspired polydopamine coated polyvinyl chloride substrate: Experimental and computational fluid dynamics modelling

A novel low-cost polyvinyl chloride (PVC) membrane was synthesized by phase inversion and fast and facile bio-inspired technique was used for substrate modification of a thin-film composite (TFC) forward osmosis (FO) membrane. Using DI water as feed solution (FS) and 1 M NaCl as draw solution (DS), water flux (WF) ranging from 4.15 to 15.95 LMH and reverse salt flux (RSF) ranging from 0.87 to 3.50 gMH were produced when the dope polymer solution concentration decreased from 17 to 10 wt%. Then, the substrate with 10 wt% PVC was selected for modification and the substrate was coated by dopamine (DA) solution for 1 and 3 h to enhance the membrane hydrophilicity and facilitate interfacial polymerization. Compared to the pristine membrane, the 1 h polydopamine (PDA) modified membrane displayed higher WF (18.90 LMH) and lower RSF (3.35 gMH). Whereas, for the longer coating time, WF decreased (9.70 LMH) due to the membrane surface pores blocking by the PDA layer. Finally, for understanding whether the experimental data can be supported by a theoretical model, the obtained experimental results were compared with a developed computational fluid dynamics (CFD) model and the results showed acceptable agreement with each other. The results of this work introduce a low-cost and facile approach for FO membrane fabrication by utilizing PVC polymer and PDA coating.

A simple approach with scale-up potential towards intrinsically flame-retardant bio-based co-plasticizer for PVC artificial materials

As an imitation of genuine leather, polyvinyl chloride (PVC) artificial materials are versatile, but suffers from being flammable due to the presence of large amounts of combustible plasticizers. Under such circumstance, intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest. However, previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures, ultimately limiting their scale-up application in industry. In addition, driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective, previously reported intrinsically flame-retardant plasticizers were mainly halogen-free, less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer. Here, we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds, yielding a chlorine-containing, intrinsically flame-retardant bio-plasticizer. When combined with di-(2-ethylhexyl) phthalate (DOP) in PVC formulations, the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings. This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials, thus being of great potential to enable intrinsically flame-retardant bio-plasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios.Graphical abstract

Evaluation of the extent of damage to the esophageal wall caused by press-through package ingestion

Press-through package (PTP) is the most common accidentally ingested foreign body in Japan. Accidental ingestion of PTP can result in esophageal damage. An approach for evaluating the risk of esophageal injury has not been established. Therefore, we used porcine esophageal tissue and silicone sheets to establish a method for assessing the risk of esophageal damage on accidental PTP ingestion. We pathologically evaluated porcine lower esophageal tissue using a scratch tester. Using porcine esophageal tissue, scratch tests were performed with 4 test objects and pathological damage was compared. It was assumed that each object was accidentally ingested. The objects were polyvinylidene chloride (PVDC)-coated polyvinyl chloride (PVC) PTP, soft PThPa, round PTP, and a disposable scalpel. The porcine esophagus was replaced with a silicon sheet, and an automatic friction machine was used for quantitative evaluation. The silicon sheet was scratched using HHS 2000 with 750-g load at 50 mm/min. We investigated the frictional force exerted on the surface for each of the objects. The degree of damage (depth) was the highest for the disposable scalpel, followed by PVDC-coated PVC PTP, while the degree of damage (depth) was the lowest for soft PThPa and round PTP. The mean frictional forces on the silicon sheet were 524.0 gf with PVDC-coated PTP, 323.5 gf with soft PThPa, 288.7 gf with round PTP, and 922.7 gf with the disposable scalpel. We developed approaches to qualitatively and quantitatively evaluate the risk of esophageal damage after accidental PTP ingestion. Our findings indicate that the risk of gastrointestinal damage after accidental PTP ingestion is low with soft PTP and round PTP.

Chemically synthesized polyaniline/polyvinyl chloride blended coatings for the corrosion protection of AA7075 aluminum alloy

Blended Polyaniline and Polyvinyl chloride coatings (thicknesses 5–30 μm) were used to protect AA7075-T6 aluminum in 3.5% NaCl solution. Electron microscopy revealed a well-defined structure with PCV predominating at the surface and constituting the bulk matrix; PANI formed agglomerates within the bulk and concentrated in a layer at the substrate/coating interface. Electrochemical tests demonstrated good performance over 15 days of exposure to saline solution; evidence includes high resistance to water uptake, low susceptibility to corrosion, and low corrosion current densities. Thick, smooth layers had the best performance and the blend outperforms a comparable pure PANI coating.

Polyaniline/polyvinyl chloride blended coatings for the corrosion protection of carbon steel

Abstract This article presents the corrosion protection ability of blended polyaniline (PANI) and polyvinyl chloride (PVC) polymers applied on 1010 steel. The PANI/PVC blends, as well as pure PANI coatings, were fabricated via a casting method and characterized using infrared spectroscopy. Carbon steel substrates protected with the coatings were subjected to 40 day exposure tests in saline (3% NaCl) and acidic (0.1 M HCl) environments and subsequently analyzed using electrochemical methods Electron microscopy (SEM) and spectroscopic methods (EDS and XPS) were used to study the corroded surface of the 1010 steel underlying the protective coating, as well as the polymer coating itself. The PANI/PVC blends demonstrated superior corrosion protection in both environments as compared to pure PANI and pure PVC coatings. The PANI/PVC blend with a 1/1 proportion offered the most effective corrosion protection in acidic and saline environments based on high charge transfer resistance values and corrosion potential values that approach zero volts. The corrosion protection abilities of the blended coatings are attributed to a combination of barrier protection from the PVC and the formation of a protective oxide layer at the steel-to-polymer interface that is facilitated by the conductivity of PANI.

Anticorrosive and Morphological Properties of Polyaniline/Polyvinyl Chloride Blend on AA7075-T6

Introduction Aluminium alloys are lightweight materials with good mechanical properties widely used in automotive and aerospace industries. Polyaniline (PANI) has been highlighted as coating given its redox properties. Mirmohseni and Oladegaragoze compared the protective effective of PANI and PVC (Polyvinyl Chloride) on iron, in solutions of NaCl and HCl, and revealed that the PANI was preferred by the formation of an oxide passive layer on the substrate induced by the redox properties of PANI [1]. Thus, in this work are presented the results regarding to the corrosion protection of PANI/PVC blends on AA7075 alloy. Experimental The PANI was synthesized from analytical grade reagents and undoped to obtain its emeraldine base (EB) form. The PVC used was purchased from Sigma-Aldrich. The blends were prepared from dispersion of PVC into NMP (N-methyl-2-pyrrolidone), under stirring, followed by addition of PANI powder. For each blend solution, the total mass used was 0.1667 g dispersed into 5 mL of NMP. That is, PANI/PVC 1/1 was consisted of 0.0834 g of PANI and the same mass amount of PVC. Finally, the electrodes (AA7075 alloy) were coated by casting, with 800 μL of PANI/PVC solution. The electrodes were heated up to 60±2 °C to evaporate the solvent. Pure PANI and PVC coatings were also prepared using the same methodology and their protective properties were evaluated. Results and Discussion Fourier Transform Infrared Spectroscopy in Transmission mode (T-FTIR) confirmed the PANI in emeraldine base (EB) form. The protective action of the coatings was evaluated toward 3.5 wt% NaCl solution. The anodic polarization curves are presented in Figure 1. The curves show expressive differences between the neat and coated substrates. The neat substrate presented a corrosion potential (Ecorr) of -1.12 V and corrosion current density (jcorr) about 6x10-6 A cm-2. All the coatings shifted to, both Ecorr and jcorr, more positive and lower values, respectively. The improved protection is assigned to the combination of the redox effect from PANI and to the resistance to electrolyte diffusion of PVC. Among the blends, PANI/PVC 1/1 was the one with highest Ecorr value (-0.041 V), followed by PANI/PVC 3/4, that had the lower jcorr (0.11 nA cm-2) and, therefore, lower corrosion rate (CR), similar to those obtained for pure PVC coating. Fig. 1. Potentiodynamic polarization curves obtained for neat AA7075-T6 alloy, PANI, PVC and PANI/PVC blends coatings in NaCl 3.5 wt% solution. Scanning Electron Microscopy coupled to Dispersive X-ray Spectroscopy (SEM-EDX) revealed the disposal of the blend compounds. From SEM images, Figure 2, can be observed that PANI and PVC (Figures 2a and 2b) display a homogeneous surface, without segregation. However, both PANI/PVC 1/1 as PANI/PVC 3/4 (Figures 2c and 2d) display an island-like phase segregation which becomes smaller as the amount of PVC increases (PANI/PVC 3/4) leading to a better distribution of the island-like forms. From contact angle data (inserts in Figure 2) is possible to affirm that all coatings have a hydrophilic characteristic with the blends presenting quite average wettability characteristics of PANI and PVC [2]. Elemental analysis mapping of chlorine (Cl Ka = 2.621 keV) obtained for PANI/PVC 1/1 (Figure 2f) revealed that the islands formed, lighter portion in Figure 2e, are mainly composed by PVC domains. Therefore, the dark portion is basically PANI domain. Fig 2. SEM images, contact angle and EDX mapping of the coating AA7075-T6 alloy, before exposure to NaCl 3.5 wt% electrolyte solution: (a) PANI, (b) PVC, c) PANI/PVC 1/1, d) PANI/PVC 3/4, (e) EDX mapping and (f) Ka mapping for elemental Chlorine in PANI/PVC 1/1. Conclusions PANI/PVC coatings were successfully deposited on AA7075 alloy. Despite heterogeneity of their morphology, revealed by SEM-EDX analysis, there was an expressive improvement of corrosion resistance of AA7075-T6 alloy toward 3.5 wt% aerated NaCl solution. The synergistic behavior between PANI and PVC in the blends led to a decrease of current density and shift of corrosion potential to more noble regions, especially PANI/PVC 1/1 and PANI PVC 3/4. Acknowledgements: The authors would like to thank the financial support of FAPESP, n° 2013/03483-2.

Effect of silica/PVC composite coatings on steel-substrate corrosion protection

In this paper we focus on the preparation of thin polymer coatings synthetized from 30-nm and 600-nm silica particles dispersed in polyvinyl chloride (PVC) and deposited on two different steel substrates: duplex DSS 2205 and austenitic AISI 316L steel. We show that a silica surface modification with silane IO7T7(OH)3 (trisilanol isooctyl polyhedral oligomeric silsesquioxane, POSS) significantly improves its dispersion properties when mixed with PVC. For comparison, the surface morphology and surface roughness of PVC coatings filled with both silanated and as-received (non-silanated) silica fillers were analyzed with scanning electron microscopy (SEM) and atomic force microscopy (AFM) when sprayed on the steel surface. The effect of the silica silanization is later on reflected in a decreased average surface roughness in the silanated, compared to non-silanated, silica/PVC-coatings. The wetting properties of the silanated and non-silanated silica/PVC-coatings on DSS 2205 and AISI 316L were investigated using contact-angle and surface-energy measurements, indicating an increased surface hydrophilicity in terms of a decreased static water contact angle and an increased total surface energy compared to the uncoated specimens. Finally, the beneficial corrosion resistance of the silica/PVC coatings was confirmed with potentiodynamic polarization spectroscopy in a 3.5% NaCl solution.

Preparation of porous super-hydrophobic and super-oleophilic polyvinyl chloride surface with corrosion resistance property

Porous super-hydrophobic polyvinyl chloride (PVC) surfaces were obtained via a facile solvent/non-solvent coating process without introducing compounds with low surface energy. The microstructure, wetting behavior, and corrosion resistance of resultant super-hydrophobic PVC coatings were investigated in relation to the effects of dosage of glacial acetic acid and the temperature of drying the mixed PVC solution spread over glass slide substrate. As-prepared PVC coatings had porous microstructure, and the one obtained at a glacial acetic acid to tetrahydrofuran volume ratio of 2.5:10.0 and under a drying temperature of 17°C had a water contact angle of 150±1.5°, showing super-hydrophobicity. In the meantime, it possessed very small contact angles for liquid paraffin and diiodomethane and good corrosion resistance against acid and alkali corrosive mediums, showing promising applications in self-cleaning, waterproof for outer wall of building, seawater resistant coating, and efficient separation of oil and water.

Adhesive polyvinyl chloride coatings for quantitative strain measurement in composite materials

A non-contact method is proposed to measure the strains on the surface of carbon fiber/epoxy composite materials using adhesive polyvinyl chloride (commonly called vinyl) coatings. Specimen preparation in digital image correlation methods yields inconsistent results due to the variability in the patterning procedure. The utility of this approach is the ability to apply computer generated randomized patterns on vinyl sheets that can be mechanically applied to the composite structure under inspection. Experimentally obtained strain values are compared to p-version finite element simulations of notched coupons showing a disparity in the correlation highly dependent on the properties of the constituents.

Sodium dodecyl sulfate coated poly (vinyl) chloride: An alternative support for solid phase extraction of some transition and heavy metals

A simple and relatively fast approach for developing a solid phase extraction has been described and used for determination of trace quantities of some heavy and transition metal ions with sodium dodecyl sulfate (SDS)-coated poly vinyl chloride (PVC) modified with bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) ligand. The adsorbed ions were stripped from the solid phase by 10 mL of 3 M nitric acid as eluent. The eluting solution was analyzed for metals content (cadmium, chromium, cobalt, copper, lead and zinc) by flame atomic absorption spectrometry (FAAS). The main factors such as pH, amount of ligand and PVC, amount and type of surfactant, and condition of eluting solutions on the sorption recovery of metal ions have been investigated in detail. The relative standard deviation was found in the range of 1.0–3.2% for 0.2 μg mL −1of metals ions. After optimization of the extraction condition and the instrumental parameters, a detection limit was found to be in the range of 1.2–3.1 μg L −1, with enrichment factor of 50 was achieved. The method was successfully applied for the determination of these metals contents in real samples with satisfactory results.

Development of the DexAide Right Ventricular Assist Device Inflow Cannula

Cannula design and cannulation site can pose major limitations to chronic pump implantations in animal studies. The aim of this study was to evaluate the biocompatibility of various inflow cannula designs for the DexAide right ventricular assist device (RVAD). The DexAide RVAD was implanted for intended durations of 14, 30, or 90 days in 19 animals (mean 20 +/- 11 days). Seven inflow cannula designs were evaluated: angled titanium conduit with caged tip (two cases); flexible polyurethane coated polyvinyl chloride (PVC) tube (one case); open ended titanium (one case); a titanium cannula with a flange (six cases); a cannula with a gelatin coated flange (five cases); a cannula with an angled flange (one case); and open ended titanium with two side holes (three cases). The open ended titanium inflow cannula with two side holes positioned through the diaphragmatic surface of the right ventricle (RV) via a right thoracotomy showed good biocompatibility for the chronic animal study. Other cannulae inserted into the infundibular portion of the RV via a left thoracotomy showed significant depositions. Gelatin coated inflow cannula had the advantage to prevent tissue growth around the inflow cannula. The DexAide RVAD pump itself showed good biocompatibility, although nonadherent depositions originating from the inflow cannulae were captured onto the primary impeller blades.

COMPLICATIONS OF CLEAN INTERMITTENT CATHETERIZATION IN BOYS AND YOUNG MALES WITH NEUROGENIC BLADDER DYSFUNCTION

We evaluate the risk for urethral lesions and epididymitis in boys with neurogenic bladder dysfunction treated by clean intermittent catheterization (CIC) for a minimum of 10 years. The medical records of 28 males with neurogenic bladder dysfunction followed from the start of CIC until the age of 15 to 20 years were reviewed. CIC had been performed for a median of 16 years (range 10 to 21). Overall CIC was used for 438 years (265 before and 173 after puberty). During 76% of the years a noncoated polyvinyl chloride catheter with lubrication was used and in 24% of years a hydrophilic coated polyvinyl chloride catheter was used. The catheter size was 12C or greater in 43% of the cases. Independence from self-catheterization occurred during 37% of the CIC years. Of the patients 19 experienced at least 1 episode of difficulty inserting the catheter and/or had macroscopic hematuria on a total of 42 occasions. Major urethral lesions were seen on cystoscopy in 7 patients on 9 occasions (5 false passages, 1 superficial recess, 2 meatal stenoses, 1 urethral stricture). Major urethral lesions were not associated with puberty and did not occur during self-catheterization or with use of catheters 12C or greater. Epididymitis was seen in only a 12 year-old boy. The overall rate of complications was low. The incidence of major urethral lesions did not increase during puberty. Self-catheterization and 12C catheter or greater seemed to be protective against major lesions.

Weathering investigation of PVC coatings on iron sheets by the NMR MOUSE

A new kind of MOUSE–the NMR mobile universal surface explorer–makes NMR investigations possible on composites with ferromagnetic components, which were previously excluded from such studies, because inhomogeneous magnetic fields are used in the first place. An example application is described, to relaxation measurements of polyvinylchloride (PVC) coatings on iron sheets. It is demonstrated that new and artificially weathered PVC coatings can be distinguished by means of their different transverse relaxation times.

Effectiveness of PVC coatings as thermal insulation for domestic hot-water piping

A 2 mm polyvinyl chloride (PVC) coating was predicted by computer modelling to be effective in reducing heat losses from pipes when they were exposed to draughts. However, the same coating was predicted to be of little benefit to pipes installed in stagnant air; a situation that would occur in many building cavities. The results predicted by the computer simulation were confirmed by wind tunnel tests at a range of air velocities. The explanation for the apparent anomaly was found in the different proportions of convected and radiated heat loss in the two situations. Where a pipe is exposed to draughts, the convective component of heat transfer is many times the magnitude of the radiative component. In these situations the addition of a PVC coating makes a significant reduction to the convective component and a less significant increase in radiated heat loss. Hence, adding the PVC produces a net reduction in the total heat loss rate. However, in relatively stagnant air the radiated component of heat transfer is more significant. Adding a PVC coating, having a higher emissivity than bare copper, increases the rate of radiant heat losses and compromises the insulation effect.

The Wear and Friction of Polyvinyl Chloride Coatings Under Fretting Conditions

The purpose of this study was to investigate the effects and interactions of load, frequency and amplitude of slip, humidity, and film thickness on the coating life and coefficient of friction of a 52100 steel ball oscillating on polyvinyl chloride coated 1045 steel disks. A two-level, five-factor experiment with two replicates per condition was performed. An analysis of variance of the film life indicated that 26 main effects and interactions were significant at the 99 percent level. Humidity wm the most significant factor; at low humidity the mean film life was 15 times that at high humidity. Load and the interaction of load and humidity were the next most significant effects. The initial and final coefficients of friction were most significantly affected by the film thickness. Presented at the 42nd Annual Meeting in Anaheim, California May 11–14, 1987

Change in properties of coatings from tacky polyvinyl chloride coatings for insulating underground pipelines

Change in properties of coatings from tacky polyvinyl chloride coatings for insulating underground pipelines