Plasticized PVC Research Articles

Construction of mammographic findings simulators to study the interference of silicone implants in the diagnosis of breast cancer

Introduction: Breast cancer is the most prevalent malignant neoplasm among women, presenting itself, in 99% of cases, in females. Augmentation mammoplasty is the most performed aesthetic surgical intervention in the world. Objective: This study aims to improve the search for biomaterials compatible with mammographic findings suggestive of malignancy, to further study the interference of silicone implants in mammography exams. Methods: To make the simulators of mammographic findings, a bibliographic study of possible biomaterials that presented compatibility with the breast tissue and with possible neoplastic findings was carried out. The validation process of the simulators made in this work was carried out in two stages. Results: The result found was a density variation between 2.54 and 2.57 (dimensionless unit). For the second plate, the individual optical density of each material was analyzed. The results found for fiberglass ranged between 1.95 and 2.63. For chicken eggshells between 0.59 and 0.80. For the glycerin suppository, values between 1.43 and 2.29 were found. And for plastic PVC film 1.78 to 2.53. Conclusion: Given the above, it is observed that the first plate as a whole is compatible with mammographic studies. However, on the second plate, when the materials were analyzed separately, it was observed that fiberglass and plastic PVC film were the closest to compatibility with the commercial phantom, being compatible materials to simulate breast neoplasms in possible further studies.

Obtaining environmentally friendly cable PVC composites

Polyvinyl chloride compositions are very popular in the cable industry. The range of domestic fireproof cable PVC plastics is limited to several manufactured brands that were developed more than 30 years ago and do not meet modern international standards. The creation of new environmentally friendly formulations of fireproof cable plastics with improved operational properties is an urgent task. This paper describes a method of synthesizing a novel ester compound of phenyl dixylenyl phosphate. The conditions for its production with maximum yield are selected. Physicochemical properties of the new flame retardant are studied. A non-toxic biodegradable PVC composition based on a plasticizer of dibutoxyethyl adipate and a novel flame retardant is formulated. The results of tests of the developed PVC-composite on the main indicators for cable products of the I40-13 brand are presented.

Sonochemical Synthesis of Laurate Sucrose Ester as Bio-Based Plasticizer and Bio-Additive for PVC

The present study shows the results obtained in the ultrasonic synthesis of sucrose esters with lauric acid, the identification of products, and the study of their possible use as bio-additives with a plasticizing effect in the processing of plastics. Fourier transform infrared spectroscopy (FTIR) and NMR (1H and 13C NMR) were used to identify the synthesized esters. The plasticizing effect of sucrose laurate was assessed by determining the glass transition temperature of thin polyvinyl chloride films by differential scanning calorimetry (DSC). The results show a decrease in the glass transition temperature with an increase in the ester concentration in the polymer, which confirms the plasticizing effect of the obtained esters.

Classifying the potential of biochars from agricultural and industrial waste for the recovery of Fe and Mn mining tailings

Various types of agricultural and industrial waste have been used for biochar production. However, a consistent method of biochar stratification for agronomic and environmental purposes is still lacking. The aim of this study was to propose and evaluate a method of stratification based on physical and chemical properties. A set of biochar samples was produced by pyrolysis and co-pyrolysis from two agricultural wastes (poultry litter - PL and swine manure - SM) and three industrial wastes (construction wood - CW, tyres - TR and PVC plastic - PVC) at a wide range of pyrolysis temperatures (300–700 °C). The proposed stratification considered the following criteria in order: (i) construction of a biochar viability indicator (BVI); (ii) classification of biochar potential based on fixed carbon, ash and volatile matter; (iii) joint use of biochar quality criteria and those established in the literature (e.g. International Biochar Initiative - IBI); and (iv) the restrictive conditions of the environment where the biochar might be applied, in this case mining tailings, aiming at plant development. Using the proposed method of stratification, PL+CW pyrolysed at 300 °C was chosen for the recovery of Fe and Mn mining tailings due to its intermediate fertility level and extremely low risk of environmental pollution. The proposed method allowed the identification of restrictions on biochar use, and most importantly, highlighted the potential of the most viable biochars for conditioning mining tailings, which hinder plant growth. However, despite being useful and efficient in biochar selection, the proposed methods are still dependent on the physico-chemical characteristics of the biochars.

Electrochemical sensor for tricyclic antidepressants with low nanomolar detection limit: Quantitative Determination of Amitriptyline and Nortriptyline in blood

Amitriptyline and its metabolite, Nortriptyline are commonly used tricyclic antidepressant (TCA) drugs that are electrochemically active. In this work, the performance characteristics of a plasticized PVC membrane-coated glassy carbon (GC) electrode are described for the voltammetric quantification of Amitriptyline and Nortriptyline in whole blood. The highly lipophilic Amitriptyline and Nortriptyline preferentially partition into the plasticized PVC membrane where the free drug is oxidized on the GC electrode. The concentrations of the drugs in the membrane are orders of magnitude larger than in the sample solution, resulting in superb limit of detection (LOD) of the membrane-coated voltammetric sensor: 3 nmol/L for Amitriptyline and 20 nmol/L for Nortriptyline. Conversely, hydrophilic components of the sample solution, e.g., proteins, the protein-bound fraction of the drugs, and electrochemically active small molecules are blocked from entering the membrane, which provides exceptional selectivity for the membrane-coated sensor and feasibility for the measurements of Amitriptyline in whole blood. In this work, the concentrations of Amitriptyline and Nortriptyline were determined in whole blood using the sensor and the results of our analysis were compared to the results of the standard HPLC-MS method. Based on our experience, the one-step voltammetric methods with the membrane-coated sensor may become a real alternative to the significantly more complex HPLC-MS analysis.

Biodegradation chemistry of new adipate plasticizers

Plastics are materials that, in the composition of various municipal solid waste, enter the environment in large quantities. Lightness and strength, the ability to withstand the effects of external factors, long-term use led to their widespread use. However, some of the additives needed to improve the performance of polymer products are highly toxic and pose a serious environmental problem. In this regard, the development of environmentally friendly PVC plasticizers is technically important. The article describes the preparation and study of the properties of ester additives based on adipic acid and ethoxylated butanol. The mechanism of biodegradation of the synthesized adipates was studied, the resulting metabolites were determined. The ecological safety of the developed plasticizers in the process of utilization in natural conditions is shown.

A citric acid/cysteine based bioadditive for plasticization and enhancing UV shielding of poly(vinyl chloride)

AbstractA new bioadditive for poly(vinyl chloride) (PVC), diethylhexyl thiazolopyridine dicarboxylate (BTD), was designed and synthesized by the esterification between 2‐ethylhexanol and thiazolopyridine dicarboxylic acid. The chemical structure of BTD was characterized by Fourier transform infrared spectroscopy and NMR. As a main plasticizer, BTD had higher plasticizing efficiency, thermal stability and migration resistance than dioctyl phthalate. Furthermore, due to the thiazolopyridine conjugated structure, BTD possessed strong ultraviolet (UV) absorption that endowed its plasticized PVC film with excellent UV shielding property. The biomass resource combined with the above high performances make BTD a very promising additive for PVC plasticization and anti‐UV application. © 2021 Society of Industrial Chemistry.

Biobased Glycerol Hyperbranched Poly(Ester)s of Precise Structure as Plasticizers for Poly (Vinyl Chloride)

Hyperbranched poly(ester)s from the renewable, abundantly-available, biomonomers, glycerol and adipic acid, may be prepared under conditions that permit control of molecular weight, avoid gelation, and ensure the presence of hydroxyl endgroups. Capping the endgroups as esters provides materials that are thermally stable, fluid at room temperature, fully compatible with a PVC matrix and provide effective plasticization of PVC at low levels of incorporation. Because of low toxicity and migratory potential, these materials represent attractive alternatives to traditional toxic plasticizers for PVC.

Ductile crack initiation and growth on a plasticized Polyvinylchloride during air bag deployment

With the goal of ensuring the security of passengers for automotive industry, the present work addresses the ductile fracture process of plasticized PVC. Dedicated clamped single edge notch bending (SENB) specimens were used to characterize the mechanisms of crack initiation and propagation for the studied material. The exploitation of the experimental database associated with finite element simulation of the crack propagation allowed, on the one hand, the calibration factor η<sub>p</sub> of this specific SENB specimen to be established, as a function of the crack depth ratio. On the other hand, the fracture toughness of the studied plasticized PVC was estimated to be 10.8 kJ/m<sup>2</sup>, value which was close to that reported in the literature for modified PVC. By using this fracture toughness value, a methodology aiming at the prediction of ductile crack initiation of the PVC skin integrated into a real dashboard (full scale test) was proposed.

Machine Learning for the Fast and Accurate Assessment of Fitness in Coral Early Life History

As coral reefs continue to degrade globally due to climate change, considerable effort and investment is being put into coral restoration. The production of coral offspring via asexual and sexual reproduction are some of the proposed tools for restoring coral populations and will need to be delivered at scale. Simple, inexpensive, and high-throughput methods are therefore needed for rapid analysis of thousands of coral offspring. Here we develop a machine learning pipeline to rapidly and accurately measure three key indicators of coral juvenile fitness: survival, size, and color. Using machine learning, we classify pixels through an open-source, user-friendly interface to quickly identify and measure coral juveniles on two substrates (field deployed terracotta tiles and experimental, laboratory PVC plastic slides). The method’s ease of use and ability to be trained quickly and accurately using small training sets make it suitable for application with images of species of sexually produced corals without existing datasets. Our results show higher accuracy of survival for slides (94.6% accuracy with five training images) compared to field tiles measured over multiple months (March: 77.5%, June: 91.3%, October: 97.9% accuracy with 100 training images). When using fewer training images, accuracy of area measurements was also higher on slides (7.7% average size difference) compared to tiles (24.2% average size difference for October images). The pipeline was 36× faster than manual measurements. The slide images required fewer training images compared to tiles and we provided cut-off guidelines for training for both substrates. These results highlight the importance and power of incorporating high-throughput methods, substrate choice, image quality, and number of training images for measurement accuracy. This study demonstrates the utility of machine learning tools for scalable ecological studies and conservation practices to facilitate rapid management decisions for reef protection.

Highly transparent plasticized PVC composite film with ideal ultraviolet/high-energy short-wavelength blue light shielding

Highly transparent plasticized PVC composite film with ideal ultraviolet/high-energy short-wavelength blue light shielding

Experimental study on the effect of modified attapulgite powder with different outlet blockage ratios on methane-air explosion

Through visual explosion experiment platform, this study conducted comparative experiments on methane-air premixed gas with a methane volume fraction of 9.5 % under different working conditions. The experiment studied the effect of active explosion suppression (spraying modified attapulgite powder) and explosion venting (setting the outlet blockage ratios) on methane explosion. The results showed that when the amount of powder injection was constant, the outlet blockage ratios of the pipeline was positively correlated with the peak explosion overpressure and the explosion index, but was negatively correlated with the peak flame propagation velocity. When the outlet blockage ratio was constant, the amount of powder spraying was negatively correlated with the peak value of explosion overpressure and the peak value of flame propagation velocity. When the outlet blockage ratio was 0, the explosion precursor shock wave broke through the PVC plastic film, which made the influx of a large amount of fresh air promote the generation of turbulence in the pipeline, and a “tulip-shaped” flame front appeared. The combination of active explosion suppression and explosion venting showed different effects on the explosion overpressure and flame propagation characteristics of methane explosion. Finally, this study conducted an in-depth discussion on the complex mechanism contained in it.

Impact of Ionic Liquid on the Dielectric and Mechanical Performance of Poly(Vinyl Chloride) (PVC)/Reduced Graphene Oxide (RGO) Nanocomposites

AbstractPoly(vinyl chloride) (PVC) composites with enhanced electrical and mechanical properties are fabricated using a hybrid filler. This study hereby reports the effect of introducing reduced graphene oxide (RGO)/ionic liquid (IL) hybrid filler on the properties of plasticized PVC. Hybrid nanostructures, if appropriately designed, are expected to combine the merits of the individual building nanomaterials. An imidazolium based ionic liquid, 1‐benzyl‐3‐methyl imidazolium tetra fluro borate is used for the hybrid formation. The structural and morphological characterization of hybrid filler using spectroscopic and microscopic techniques confirms the successful formation of hybrid. Dielectric constant is found to be increased even by the addition of a small quantity of ionic liquid to RGO. The ionic moieties in the added ionic liquid in addition to the π bonds in the RGO are found to be responsible for the enhancement. Elongation at break is found to be increased with addition of hybrid filler due to the plasticizing action of the ionic liquid. It is clear from the investigations that ionic liquid, 1‐benzyl‐3‐methyl imidazolium tetra fluro borate can be used as an efficient modifier for RGO.

Influence of a mixture of calcium and zinc stearates on the thermal and mechanical properties of PVC plastic

A complex stabilizer based on a mixture of calcium and zinc stearates was developed, which was used to replace the tribasic lead sulphate in the formulation of cable polyvinyl chloride plasticate. The influence of a complex stabilizer on the basic physical and mechanical properties of cable polyvinyl chloride plasticate is investigated. It was found that the use of a complex stabilizer in the formulation of cable polyvinyl chloride plasticate does not lead to a decrease in the thermal, technological and operational characteristics of the material. It is shown that the thermal properties of the cable compound containing a complex stabilizer remains at the level of the original plastic. This is due to the ability of the complex stabilizer to effectively bind hydrogen chloride released during the destruction of the polymer matrix. It is established that the cable polyvinyl chloride plasticate containing in the formulation of a complex stabilizer in its mechanical characteristics is not inferior to the industrial compound, and in some respects surpasses it.

High-Performance Liquid Chromatography Method for Simultaneous Determination of Bisphenols in Plastic Packed Dry Fruits Using Multi-walled Carbon Nanotubes as Solid Phase Extraction Sorbent

Background: Bisphenols A (BPA), bisphenol S (BPS), and bisphenol F (BPF) are manufactured chemicals found in food packaging, drink containers, lotions, toys, plastic PVC flooring, and water pipes. The aim of this work is to develop simple, rapid and reliable high-performance liquid chromatography with fluorescence detector (HPLC-FLD) method for simultaneous determination of bisphenols A (BPA), bisphenol F (BPF), and bisphenol S (BPS) in plastic packed dry fruits collected from Saudi Arabia markets. Methods: BPA, BPS and BPF in plastic packed dry fruits samples were extracted and clean up using packed Multi-Walled Carbon Nanotubes (MWCNTs) mini-column followed by analysis using HPLC-FLD. Results: The three BPs were separated within less than 12 min. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision (repeatability) and accuracy (recovery). Good linearity was obtained in the concentration range of 62.25-10000 μg/L for BPS and 6.25-1000 μg/L for BPA and BPF. The LODs and LOQs were found to be 1.07, 12.09, and 0.9939 μg/L and 3.56, 40.32 and 3.13 μg/L for bisphenols BPA, BPS, and BPF, respectively. Recoveries for analytes in the samples were all within the range of 87% to 104%. Conclusion: The method was successfully applied to real dry fruit samples (i.e, dry date (Ajwa), apricot, dry grapes and figs. The results obtained revealed that all of the tested BPs were present in the samples.

Estimating mouthing exposure to chemicals in children\u2019s products

BackgroundExisting models for estimating children’s exposure to chemicals through mouthing currently depends on the availability of chemical- and material-specific experimental migration rates, only covering a few dozen chemicals.ObjectiveThis study objective is hence to develop a mouthing exposure model to predict migration into saliva, mouthing exposure, and related health risk from a wide range of chemical-material combinations in children’s products.MethodsWe collected experimental data on chemical migration from different products into saliva for multiple substance groups and materials, identifying chemical concentration and diffusion coefficient as main properties of influence. To predict migration rates into saliva, we adapted a previously developed migration model for chemicals in food packaging materials. We also developed a regression model based on identified chemical and material properties.ResultsOur migration predictions correlate well with experimental data (R2 = 0.85) and vary widely from 8 × 10−7 to 32.7 µg/10 cm2/min, with plasticizers in PVC showing the highest values. Related mouthing exposure doses vary across chemicals and materials from a median of 0.005 to 253 µg/kgBW/d. Finally, we combined exposure estimates with toxicity information to yield hazard quotients and identify chemicals of concern for average and upper bound mouthing behavior scenarios.SignificanceThe proposed model can be applied for predicting migration rates for hundreds of chemical-material combinations to support high-throughput screening.

Experimental Study of Water Collection from Plume of an Induced-Draft Counter-Flow Cooling Tower Using Space Charge Injection

Plume collection from cooling towers can be a reliable solution to the water scarcity problem faced in many regions around the world. Meshes are one of the most proposed collectors in this regard that rely upon inertial collision for droplet capture and are inherently limited by aerodynamics. This study quantifies the effect of electrical forces on water collection from the plume of an Induced Draft Counter Flow (IDCF) Cooling Tower by introducing sets of copper tubes at the exit of the tower. The imparting of net charge to the exhaust plume by instigating space charge directs the vapor towards the inside wall of copper tube forming water droplets. This arrangement instead of a mesh or net system, creates a lesser obstruction to flow. Fabrication of fill/packing with a corrugated wave pattern using PVC plastic demonstrates satisfactory cooling performance of the tower. An optimized L/G ratio is found to exist for maximum collection efficiency of water from plume at definite entering fluid temperatures by investigating with the entering warm water temperatures at 40°C, 45°C and 50°C while the dry bulb temperature of air ranges from 23.5°C to 30.1°C. The electricity consumption for this arrangement fluctuates from 2.78 kWh/m3 to 5.13 kWh/m3 for two L/G ratios (23.5 and 28.3). Where maximum collection percentage occurs at two different entering fluid temperatures, the power expended is below the minimum used for typical desalination plants.

Effect of ketal group in castor oil acid‐based plasticizer on the properties of poly(vinyl chloride)

AbstractTwo castor oil acid esters containing a ketal or ketone group (KCL or CL), as alternative plasticizers for poly(vinyl chloride) (PVC), were prepared. The structures were confirmed by1H NMR and FTIR spectroscopies. The effects of the presence of a ketal or ketone group in these compounds on PVC plasticization were examined. The DMA and SEM results showed that both plasticizers were miscible with PVC and exhibited excellent plasticizing properties, compared to those of dioctyl phthalate (DOP). The PVC plasticized by KCL displayed a lowerTgvalue of 20.6°C, which was lower than that of PVC plasticized with DOP (22.3°C) and PVC plasticized with CL (40.5°C). Tensile tests indicated that PVC plasticized using KCL showed a 37% higher of elongation at break than PVC plasticized by CL and 30% higher than PVC plasticized by DOP. The plasticizing mechanism was also investigated. Moreover, exudation, volatility, and extraction tests, along with TGA indicated that the presence of ketal groups effectively improved the migration resistance of plasticizer and the thermal stability of PVC blends. Taken together, introducing ketal groups into plasticizer might be an effective strategy for improving its plasticizing efficiency.

Enhancement of flame retardancy and physical property for poly(vinyl chloride) having renewable cardanol-based self-polymerizable phosphonate under heat treatment process

Considering the drawbacks of conventional plasticizers used for poly(vinyl chloride) (PVC), it is imperative to develop bio-based additives. Herein, bis(cardanyl) phenylphosphonate (CP), which is not only a flame retardant but also a plasticizer for PVC, was designed and synthesized from cardanol. The flame retardancy and flexibility of PVC improved with an increase in the CP content (wt%) because of the presence of the phosphonate group and long alkyl chain of CP, respectively. Meanwhile, we found that CP can be self-polymerized by heat treatment and that the cross-linked network of CP leads to an additional enhancement in the flame retardancy of PVC by inducing anti-dripping property and the formation of graphitized char layer. Also, the flexibility of the PVC films was preserved without deteriorating its transparency. CP with self-polymerization properties is a promising candidate to improve the thermal stability, flame retardancy, and flexibility of PVC while maintaining its transparency and migration stability.

Impact speed dependency of the ductile failure threshold temperature for a plasticized polyvinylchloride

With the goal of ensuring the security of passengers for automotive industry, the present work addresses the temperature and impact speed envelope allowing ductile failure of plasticized PVC to be obtained. A database of about 250 test results has been constructed for various conditions at ten test temperatures, four impact speeds and two specimen geometries (with or without scoring). The desired ductile failure was characterized by the shape of the load versus deflection curve together with the fracture surface morphology obtained. The temperatures for obtaining ductile failure threshold (\(T_{\mathrm {dth}}\)) have been plotted as a function of the impact speeds for the two geometries. A gap of 20 \(^{\circ }\)C on the \(T_{\mathrm {dth}}\) was highlighted between the two geometries. Additionally, the impact strength of the plasticized PVC under study was estimated to be 0.25 kJ/m\(^2\).