Commercial Poly Vinyl Chloride Research Articles

Impact of polyvinyl chloride microplastic exposure on the hepatopancreas metabolism of Pinctada fucata martensii: Insights from metabolomics

Microplastics (MPs) are prevalent throughout the oceans and pose a significant global environmental concern due to their detrimental effects on various living organisms. While researchers have investigated the toxicity mechanisms of MPs in marine species, there is a need for a more comprehensive understanding, particularly regarding the potential adverse effects on the growth and metabolism of bivalves. In this study, indoor exposure experiments were conducted on Pinctada fucata martensii to examine the impact of commercial polyvinyl chloride (PVC)-MPs (50 μm, 15 mg/L). The aim was to determine the effects of MPs on the hepatopancreas metabolism of P. f. martensii. Non-targeted metabolomics analysis indicated alterations in the hepatopancreatic metabolic of P. f. martensii following exposure to PVC-MPs. A total of 32, 27, and 154 differential metabolites (SDM) were identified in EG (1-d) vs CG (1-d), EG (15-d) vs CG (15-d), and EG (1-d) vs EG (15-d), respectively (VIP >1 and P < 0.05). Further examination of metabolic pathways revealed that PVC-MPs disrupted the metabolism of amino acids, particularly alanine, aspartic acid, and glutamic acid metabolism; this suggests that the organism may have developed neurotoxicity. Sphingolipid metabolites showed a significant up-regulation in both EG (15-d) vs CG (15-d), as well as in EG (1-d) vs EG (15-d), indicating lipid peroxidation in the hepatopancreas of P. f. martensii following PVC-MPs exposure. Additionally, in EG (1-d) vs CG (1-d), starch and sucrose metabolism were significantly inhibited, glycolysis or gluconeogenesis pathways were promoted, and changes in energy metabolism were promoted. This study sheds light on the impact of MPs on the metabolism of bivalves, offering fresh insights into the detrimental effects of MPs on aquatic organisms.

Bisphenol A sorption on commercial polyvinyl chloride microplastics: Effects of UV-aging, biofilm colonization and additives on plastic behaviour in the environment.

Chemical additives are important components in commercial microplastics and their leaching behaviour has been widely studied. However, little is known about the potential effect of additives on the adsorption/desorption behaviour of pollutants on microplastics and their subsequent role as vectors for pollutant transport in the environment. In this study, two types of commercial polyvinyl chloride (PVC1 and PVC2) microplastics were aged by UV irradiation and biotic modification via biofilm colonization to investigate the adsorption and desorption behaviour of bisphenol A (BPA). Surface cracks and new functional groups (e.g., O–H) were found on PVC1 after UV irradiation, which increased available adsorption sites and enhanced H‒bonding interaction, resulting in an adsorption capacity increase from 1.28 μg/L to 1.85 μg/L. However, the adsorption and desorption capacity not showed significant changes for PVC2, which might be related to the few characteristic changes after UV aging with the protection of light stabilizers and antioxidants. The adsorption capacity ranged from 1.28 μg/L to 2.06 μg/L for PVC1 and PVC2 microplastics, and increased to 1.62 μg/L—2.95 μg/L after colonization by biofilms. The increased adsorption ability might be related to the N–H functional group, amide groups generated by microorganisms enhancing the affinity for BPA. The opposite effect was observed for desorption. Plasticizers can be metabolized during biofilm formation processes and might play an important role in microorganism colonization. In addition, antioxidants and UV stabilizers might also indirectly influence the colonization of microorganisms’ on microplastics by controlling the degree to which PVC microplastics age under UV. The amount of biomass loading on the microplastics would further alter the adsorption/desorption behaviour of contaminants. This study provides important new insights into the evaluation of the fate of plastic particles in natural environments.

Study on Sound Absorption Properties of Polyvinyl Chloride (PVC) Film Multicavity Structure Materials

Since the development of industry, sound absorption and noise reduction have gradually become an urgent problem to be solved. Lightweight polymer film materials are very effective in response to sound waves, and sound waves can easily cause vibration of the film, which can convert sound energy into vibration and film friction to achieve sound absorption. The application conditions of the film material are very harsh, that is, a support body is required to fix the film and the film needs to be tensioned. The film is very thin and easy to damage. The idea of this research is to transform the film into a bubble structure and use a large number of film bubbles to form a cavity structure material. As a unit of the sound absorption structure, bubbles can avoid damage to the film. In this paper, commercial polyvinyl chloride film bubble materials are used to prepare two kinds of film multicavity structure materials, and the sound absorption performance of this film multicavity structure material is studied. The research results show that this film multicavity structure material has very excellent broadband sound absorption performance, which changes the narrow band sound absorption properties of the usual film single cavity. The average sound absorption coefficient can reach 0.84 in frequency range from 500 Hz to 6400 Hz. This structural material has a single peak sound absorption curve at the middle and low frequency bands, which is the characteristic of resonance sound absorption. And at the middle and high frequency bands, it exhibits the characteristics of broadband sound absorption. The film multicavity structure material has both cavity sound absorption and broadband sound absorption characteristics.

The release, degradation, and distribution of PVC microplastic-originated phthalate and non-phthalate plasticizers in sediments

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 3579% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall, 94%), there was a noticeable abiotic loss (72%), suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly, when compared with the initial sediment-water partitioning for plasticizers, the partition constants for low-molecular-weight compounds decreased in both microcosms, whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore, changes in the bacterial community, abundance of plasticizer-degrading bacterial populations, and functional gene profiles were assessed. In all the microcosms, a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter, Bacillus, Desulfovibrio, Desulfuromonas, Devosia, Gordonia, Mycobacterium, and Sphingomonas, among which Bacillus was recognized as the key plasticizer degrader. Overall, these findings shed light on the factors affecting plasticizer degradation, the microbial communities potentially involved in biodegradation, and the fate of plasticizers in the environment.

Robust and self-lubricating polyvinyl alcohol tubes with a mucosa-like hierarchical architecture for endotracheal intubation.

Mechanical mismatch between interventional intubation tubes and human tissues often triggers inevitable friction and causes secondary injury to patients during interventional therapy. Herein, we propose a fabrication strategy of a self-lubricating polyvinyl alcohol (PVA) tube by industrial extrusion technology followed by simple infiltration with water. First, biocompatible glycerin was introduced to weaken the intrinsic hydrogen interaction of PVA by new molecular complexation, broadening the gap between the melting and decomposition temperatures and enabling the stable extrusion of the PVA tube. Subsequently, the as-prepared PVA tube was infiltrated with an aqueous solution to construct a strong hydrogen bonding network between PVA and water molecules, forming a soft hydration layer similar to the upper epithelium layer of mucosa. Benefiting from the solid and liquid properties of the hydration layer as well as the small proportion relative to the whole, the infiltrated PVA tube exhibited excellent hydration lubrication behavior and robust mechanical property. The friction coefficient, tensile strength and elongation at break were measured to be 0.05, 26.2 MPa and 654%, respectively, surpassing the values of 0.5, 16.4 MPa and 240% observed in a commercial polyvinyl chloride tube. In vitro, the PVA intubation tube demonstrated significant biocompatibility, and short-term exposure exhibited minimal impacts on the morphology and proliferation of L929 cells. Ultimately, the potential of the infiltrated PVA tube for interventional intubation was demonstrated successfully using an in vivo rabbit model, providing a new idea for the follow-up development of interventional intubation tubes.

An effective air–liquid contactor for CO2 direct air capture using aqueous solvents

The development of a cost-effective, corrosion resistant, high-flux direct air capture (HiDAC) contactor for a solvent-based direct air capture (DAC) process is reported. Literature technoeconomic analyses suggest that the air–liquid contactor can cost over 20 % of the overall DAC plant’s annualized capital costs. To bring down the overall cost of DAC, it is imperative that an effective contactor is developed. A hybrid contactor consisting of a commercial polyvinylchloride structured packing enhanced with stainless-steel 410 random packing has been developed to provide a high surface area for air–liquid contact. The contactor geometry, wettability, corrosion resistance, pressure drop, along with its CO₂ uptake efficiency, CO₂ uptake rates, and extended loading potential using potassium sarcosinate solutions are investigated. Results show that the HiDAC contactor has a relatively high specific surface area (885 m2/m3), which allows for CO₂ uptake efficiencies of up to 75 % and capture rates of up to 550 g of CO₂ per day for a 0.3 × 0.25 × 0.3 m contactor. The contactor also exhibits high levels of wettability and corrosion resistance with amino acid-based DAC solvents. A CO₂ uptake model was developed, and modeling results are compared to experimental data to simulate and predict the performance of the contactor in a DAC process using potassium sarcosinate solvent. The system’s overall mass transfer coefficient and theoretical pressure drop were also calculated, and these results were compared to DAC data found in literature. The results presented indicate that the HiDAC contactor is well suited for DAC due to its high specific surface area, resistance to corrosion, and high degree of wettability.

Enhanced migration of plasticizers from polyvinyl chloride consumer products through artificial sebum

In the present study, the migration of plasticizers from modeled and commercial polyvinyl chloride (mPVC and cPVC, respectively) to poly(dimethylsiloxane) via artificial sebum was assessed to mimic the dermal migration of plasticizers. In addition, the various factors affecting migration of phthalic acid esters (PAEs) from diverse PVC products were investigated. The migrated mass and migration ratio of PAEs increased but the migration rate decreased over time. The migration rate increased with sebum mass, contact time, and temperature but decreased under higher pressure. Low-molecular-weight PAEs (dimethyl phthalate and diethyl phthalate) migrated in higher amounts than high-molecular-weight PAEs (dicyclohexyl phthalate [DCHP] and diisononyl phthalate [DINP]). Diffusion of all PAEs in mPVC increased with temperature, with diffusion coefficients ranging from 10−13 to 10−15, 10−12 to 10−14, and 10−10 to 10−12 cm2·s−1 at 25 °C, 40 °C, and 60 °C, respectively; the enthalpy of activation ranged between 127 and 194 kJ·mol−1. Moreover, migration depended on total PAE content of the product, as the diffusion coefficient for DINP in cPVC (softer PVC) was approximately three orders of magnitude higher than that for DINP in mPVC (harder PVC); this may be due to the increase in free volume with increasing plasticizer content. Finally, the daily exposure doses of the plasticizers were estimated. These findings will be helpful for estimating dermal exposure risk.

In vitro toxicity assessment of polyethylene terephthalate and polyvinyl chloride microplastics using three cell lines from rainbow trout (Oncorhynchus mykiss)

The RTgill-W1 (gill), RTG-2 (gonad), and RTL-W1 (liver) cell lines derived from a freshwater fish rainbow trout (Oncorhynchus mykiss), were used to assess the toxicity of polyethylene terephthalate (PET) and two forms of polyvinyl chloride (PVC). Two size fractions (25-μm and 90-μm particles) were tested for all materials. The highest tested concentration was 1 mg/ml, corresponding to from 70 000 ± 9000 to 620 000 ± 57 000 particles/ml for 25-μm particles and from 2300 ± 100 to 11 000 ± 1000 particles/ml for 90-μm particles (depending on the material). Toxicity differences between commercial PVC dry blend powder and secondary microplastics created from a processed PVC were newly described. After a 24-h exposure, the cells were analyzed for changes in viability, 7-ethoxyresorufin-O-deethylase (EROD) activity, and reactive oxygen species (ROS) generation. In addition to the microplastic suspensions, leachates and particles remaining after leaching resuspended in fresh exposure medium were tested. The particles were subjected to leaching for 1, 8, and 15 days. The PVC dry blend (25 μm and 90 μm) and processed PVC (25 μm) increased ROS generation, to which leached chemicals appeared to be the major contributor. PVC dry blend caused substantially higher ROS induction than processed PVC, showing that the former is not suitable for toxicity testing, as it can produce different results from those of secondary PVC. The 90-μm PVC dry blend increased ROS generation only after prolonged leaching. PET did not induce any changes in ROS generation, and none of the tested polymers had any effect on viability or EROD activity. The importance of choosing realistic extraction procedures for microplastic toxicity experiments was emphasized. Conducting long-term experiments is crucial to detect possible environmentally relevant effects. In conclusion, the tested materials showed no acute toxicity to the cell lines.

Fabrication of electrospun membranes for air sampling applications: A statistical optimization approach

Introduction: The applicability of Nanofiber (NF) membranes in air sampling of pollutants for the purpose of determining the airborne concentration has received little attention around the world. The present study aims to optimize the fabrication of NF membrane for the of air sampling application.&#x0D; Materials and methods: The polyvinyl chloride NF membranes were fabricated using needle-based solution electrospinning technique. The experimental design was prepared by Design-Expert v7.0 and data analysis was done by Central Composite Design (CCD) base on Response Surface Methodology (RSM) technique. The ability of the fabricated membranes in air sampling applications was performed by sampling of airborne crystalline silica by them using the National Institute for Occupational Safety and Health (NIOSH7602) method and then comparing with the commercial PVC membranes.&#x0D; Results: The fabricated NF membranes had a mean porosity of 31.60% compared to a porosity of 25.1% in the case of commercial Polyvinyl Chloride (PVC) membranes. The electrospun NF membranes had mean pressure drop of 194.23 Pa, which is lower than the 204 Pa pressure drop of commercial PVC filters. The mean concentration of silica sampled by the electrospun NF membrane was 0.14 mg/m3 while this was 0.03 mg/m3 for commercial PVC membrane. The difference concentration of crystalline silica sampled by NF and commercial PVC membranes had the strongest relationship with the electrospinning solution concentration (r=-0.785, p&gt;0.05).&#x0D; Conclusion: The NF membrane has high performance in sampling the crystalline silica dust from the air stream compared to commercial PVC membranes.

Biodeterioration of Compost-Pretreated Polyvinyl Chloride Films by Microorganisms Isolated From Weathered Plastics.

Polyvinyl chloride (PVC) is a petroleum-based plastic used in various applications, polluting the environment because of its recalcitrance, large content of additives, and the presence of halogen. In our case study, a new, two-stage biodegradation technology that combined composting process used for PVC pretreatment with a subsequent PVC attack by newly-isolated fungal and bacterial strains under SSF conditions was used for biodegradation of commercial PVC films. The novelty consisted in a combined effect of the two biodegradation processes and the use for augmentation of microbial strains isolated from plastic-polluted environments. First, the ability of the newly-isolated strains to deteriorate PVC was tested in individual, liquid-medium- and SSF cultures. Higher mass-reductions of PVC films were obtained in the former cultures, probably due to a better mass transfer in liquid phase. Using the two-stage biodegradation technology the highest cumulative mass-reductions of 29.3 and 33.2% of PVC films were obtained after 110 days with Trichoderma hamatum and Bacillus amyloliquefaciens applied in the second stage in the SSF culture, respectively. However, FTIR analysis showed that the mass-reductions obtained represented removal of significant amounts of additives but the PVC polymer chain was not degraded.

Experimental and numerical analysis of the ballistic response of agglomerated cork and its bio-based sandwich structures

Considering the susceptibility of sandwich structures to impact events and the increasing environmental awareness due to pollution, the present work provides a thorough understanding of the ballistic impact behavior of agglomerated cork and of the resulting green sandwich structures produced with polypropylene (PP) skins reinforced with a flax/basalt intraply hybrid fabric. The effect of density on the agglomerated cork response was evaluated (NL10 ρ = 0.14 g/cm3, NL20 ρ = 0.20 g/cm3 and NL25 ρ = 0.25 g/cm3) and a comparison with commercial polyvinyl(chloride) foams was provided (HP130 ρ = 0.13 g/cm3, HP200 ρ = 0.20 g/cm3 and HP250 ρ = 0.25 g/cm3). The effect of a maleic anhydride coupling agent on the mechanical properties of the skins and of the overall sandwich structures was also investigated. The results highlighted a compromising effect of the weak interface between cork granules and polymeric binder on the impact resistance of the agglomerated cork, but a clear improvement of its performance was observed when embedded as core material between the two skins. Indeed, the two classes of sandwich structures produced with neat PP skins and with the two cores with the same density, i.e. agglomerated cork NL10 and PVC foam HP130, displayed the same ballistic limit of 171 m/s confirming that cork integration in the overall structures allows to approach PVC foam performance. The high-velocity impact response of one agglomerated cork (NL25) and one PVC foam (HP130) was also subjected to finite element analysis employing the CRUSHABLE FOAM model available in ABAQUS obtaining a good fitting with the experimental data.

Additives as a major source of radiolytic organic byproducts of polyvinyl chloride (PVC)

Polyvinyl chloride (PVC), one of the most polymeric materials present in the radioactive waste, is exposed to radiooxidation process during disposal and generates many byproducts. Commercial PVC materials usually contain many additives to provide desired properties and to improve their stability during shaping and lifetime. The additives generally delay PVC radiolysis limiting the formation of some PVC transformation compounds, but they can indubitably generate byproducts as well. Hence, the present work investigates the role of the additives in formulated PVC on the nature and kinetics of the released radiolytic compounds. Four PVC samples, one resin, two PVC formulated on purpose and one commercial PVC containing different additives (at least di-isononyl phthalate (DINP) as plasticizer) were exposed to γ irradiation. Analyses by thermal desorption-GC-MS and solvent extraction coupled with GC-MS were undertaken to identify radio oxidative products. Higher amounts of volatile and non-volatile organic compounds were detected in formulated PVC compared to PVC resin. Some are products coming from the degradation of the polymer chain while the others result mainly from the radiolytic degradation of DINP plasticizer. Commercial PVC containing the widest range of additives (among other lubricants) produced additional byproducts coming from their degradation. Based on the identification and evolution of the radio oxidized products, mechanistic pathways involved in the radiolytic degradation of formulated PVC are proposed.

Effects of chemical and natural ageing on the release of potentially toxic metal additives in commercial PVC microplastics

Various chemical substances, such as potentially toxic trace metals, are used as plastic additives to improve the performance of polymers and extend the service life of plastic products. However, these added trace metals are likely released from plastic into the environment when the plastic becomes a pollutant, although the process is poorly understood. In this study, chemical ageing of commercial polyvinyl chloride (PVC) microplastics using hydrogen peroxide (H2O2) and natural ageing of PVC that had been added to an alkaline paddy soil were undertaken to evaluate the potential release of trace metals from PVC. Enhanced release of trace metals from PVC with the increasing H2O2 concentrations was observed, in which the released Pb was 1–2 orders of magnitude higher than other metals (p < 0.01). The released Cr, Ni, Pb, Cu, Zn, Cd and Mn accounted for 87.37%, 79.27%, 22.02%, 20.93%, 17.06%, 15.11%, and 11.02% of their total concentrations (0.28 ± 0.03, 0.08 ± 0.01, 13.67 ± 0.18, 1.07 ± 0.02, 2.20 ± 0.18, 0.05 ± 0.00 and 1.26 ± 0.08 mmol kg−1) in PVC after ageing with 30% H2O2, respectively. Compared with the control treatment without PVC addition, the concentrations of CaCl2-extractable Cu, Mn, Ni, Pb, and Zn in the soil treated with 5% PVC are significantly increased after incubation for 60 days (p < 0.01). In conclusion, chemical and natural ageing have the potential to lead to the release of Cu, Mn, Ni, Pb, and Zn from the commercial PVC into aquatic and terrestrial environments.

One-pot polyvinyl chloride preparation utilizing polyacrylate latex with tertiary amine groups for improved thermal stability, toughness, and reduced reactor scaling

In this paper, crosslinked polyacrylate latex with tertiary amine groups (ACLN) and base latex without tertiary amine groups (ACL) were prepared by emulsion polymerization using butyl acrylate as the monomer and 1,4-butanediol dimethacrylate as the crosslinker. Composite resins of polyvinyl chloride (PVC), ACL/PVC and ACLN/PVC, were prepared by suspension polymerization of vinyl chloride in a 20 L high-pressure reactor by adding ACL and ACLN as modifiers. The inner pressure of the reactor and initiator concentration as a function of reaction time during suspension polymerization were studied. Morphology of resin particles, processing properties, thermal stability and mechanical properties of ACL/PVC and ACLN/PVC products were investigated. A commercial PVC product named PVC-SG5 was used as the control sample for comparison. It was found that compared with typical PVC-SG5 preparation, ACL/PVC fabrication took less time while initiator concentrations needed to be increased to 2400 ppm in ACLN/PVC preparation in order to complete the polymerization within the same time. Reactor scaling occurred during ACL/PVC preparation, but could be avoided in ACLN/PVC preparation owing to the hydrophilicity of ACLN. The morphology of ACL/PVC and ACLN/PVC particles was smooth microspheres and mosaic particle shapes, respectively, the diameter of which were all smaller than PVC-SG5 particles. The covalent-bonding existing in ACL/PVC and ACLN/PVC, and ionic-bond formation of quaternary ammonium in ACLN/PVC composite resins, between tertiary amine groups in ACLN and chlorine atoms in PVC, contributed to the dramatic increase in thermal stability. ACLN/PVC exhibited the shortest plasticizing time and the longest elongation at break, followed by ACL/PVC. The toughness of both ACL/PVC and ACLN/PVC were greatly enhanced without affecting the tensile strength and softening temperature of the resin. Thus, three issues, namely, low thermal stability, low toughness and reactor scaling during polymerization of PVC have been comprehensively solved by introducing ACLN to PVC through a one-pot method.

Test and Evaluation Procedure of Foam Core Materials for Composite Ships

Sandwich structures are general-purpose structures that can reduce the structural weight of composite ships. Core materials are essential for these structures, with polyvinyl chloride (PVC) foams being the most popular. These foam core materials are subjected to various tests in the development process, and must satisfy the performance requirements of several ISO and ASTM standards. Therefore, a procedure for evaluating the performance of foam core materials was proposed in this paper. In addition, prototypes were fabricated using a commercial PVC foam core product in accordance with the structural design of an 11 m fiber-reinforced plastic yacht. Then, a case study was conducted on the proposed evaluation procedure. The proposed procedure facilitates the understanding of the performance requirements and evaluation of core materials used in composite ships and is expected to be utilized in developing core materials for marine structures.

Sensitive Fluorescence Detection of Phthalates by Suppressing the Intramolecular Motion of Nitrophenyl Groups in Porous Crystalline Ribbons.

A novel, highly sensitive fluorescence sensor for phthalates is developed by introducing nitrophenyl groups to a trifluorene molecule that can form porous crystalline ribbons. On the basis of single-crystalline analysis and theoretical calculations, we demonstrate that phthalate molecules can diffuse into the caves of crystalline ribbons and effectively suppress the rotation of nitrophenyl groups via noncovalent interactions to enhance the emission. Because of this novel response mechanism, fluorescence detection of phthalates with high sensitivity (the limit of detection of widely used di(2-ethylhexyl) phthalate (DEHP) is 0.03 ppb) and rapid reversible turn-on responses is achieved. Sensitive detection of phthalates released from commercial polyvinyl chloride (PVC) products further illustrate the utility of such a sensor in in situ and real-world applications.

POSTHARVEST QUALITY AND CHILLING INJURY OF “SUCCARY” POMEGRANATES AS AFFECTED BY DIFFERENT PACKAGING TYPES

Fully ripe 'Succary' pomegranate fruits were harvested from a private orchard in Ismailia, Egypt in 2015 &amp; 2016 seasons. The fruits were packed in: 1- freely packed fruits (control) 2- sealed fresh bags of high ethylene absorption (HEA) 3- perforated polyethylene )PPE( 4- polyethylene (PE) film (stretchable cling film) 5- commercial PVC (poly vinyl chloride) pages. All packaging treatments were stored at 5 ºC and 90 – 95% RH for 12 weeks. Samples were taken every 2 weeks followed by 4 days at 20˚C. Fruit weight (g) rind thickness (mm), aril /fruit (%), juice content %, juice colour, SSC, acidity%, total sugars%, total phenols% and vitamin C were evaluated at harvest time. Chilling injury of the fruit was reduced by all packaging types. Changes in acidity, and SSC of the packed fruits were lower than that of freely packed fruits (control) during storage period. Cold storage at 5 °C with packaging treatments would be the best for preserving the freshness and vitamin C, increasing antioxidant activity, reducing chilling injury and maintaining fruit quality. Consequently, the fruits were more commercially acceptable.

Analysis of Phthalate Ester Content in Polyvinylchloride Construction Plastics by RAMAN Spectroscopy

There is serious concern that fat-soluble phthalates such as di (2-ethylhexyl) phthalate, or DEPH. Phthalates are not chemically bonded to the PVC and will with time escape by evaporation or by extraction when in contact with liquids. Raman spectroscopy excited with a 785 nm laser can be used to determine the content of plasticizers in commercial flexible polyvinyl chloride (PVC) construction plastics. This method is very convenient for rapid non-destructive remote determination of phthalates, such as for quality control of production lines, quality control or at customs.

Fabrication of Nanostructured Carbon on the Surface of Commercial Polymers Using a High-Energy Ion Beam

The impact of a nanosecond high-energy ion beam (HEIB) on thin films of commercial chlorinated polyvinyl chloride (CPVC) and polyvinyl alcohol (PVA) containing catalytic additives (inorganic iron salts) is studied. Depending on the type of polymer, the type of additive, and the irradiation mode used, HEIB treatment results in the formation of either layers of carbon nanofibers or a carbon foam on the polymer surface. The most probable diameters of the carbon nanofibers are 70 and 40 nm for CPVC and PVA, respectively. The mechanism explaining the effect of the catalytic additive on the formation of nanostructured carbon on the surface of the considered polymers is discussed.

Starch and Starch/Bacterial Nanocellulose Films as Alternatives for the Management of Minimally Processed Mangoes

Improving the storage of minimally processed mangoes represents a substantial challenge for packaging. For this purpose, thermoplastic starch (TPS) and its composites with bacterial cellulose nanoribbons (TPS/BC) are used as wrapping materials to prolong the shelf life of minimally processed mangoes. Commercial polyvinyl chloride stretch (PVC) films and unwrapped mangoes are used as the controls. The samples were stored at 75% RH and 5 °C for five and ten days. The films are removed after storage and subjected to mechanical tests and physical evaluation. The weight loss, firmness, total soluble solids, and total titratable acidity in the mangoes are tested to monitor fruit ripening. ATR-FTIR is used as an alternative nondestructive technique to examine fruit quality through changes in the sugar and organic acid contents. The results showed that TPS films reduced mango weight loss until the fifth day (2.84%), whereas the reduction in weight loss seen in mangoes wrapped with TPS/BC is even lower (13.18%). Therefore, even though both TPS and TPS/BC films can be used to prolong the fruit shelf life for five days, the latter is more effective. The elongations at break of both film samples remained constant over time, which means that these films can be used under stress conditions.