The present study investigated the application of recycled Polyvinyl chloride ((PVC)) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. Three types of (PVC) were used as the matrix (100% virgin (PVC), 100% recycled (PVC), and a mixture of the equal weight of virgin and recycled (PVC)). Maleic anhydride grafted polypropylene (MAPP) was used as the coupling agent at a fixed dosage of 5% based on the (PVC) weight. The composite panels were produced using injection molding and the physical and mechanical properties of the final boards were evaluated according to ASTM standard test methods. Results showed that the utilizing the mixture of virgin and recycled (PVC) increased the bending strength and modulus of elasticity. Water absorption was also increased. However, impact resistance and elongation at yield point were decreased. At higher wood flour content up to 40%, flexural strength was increase indicating that the resin properly encapsulated the wood flour particles and at higher wood flour dosage, elongation and Izod impact resistance was reduced.

Pollution of the aquatic environment by microplastics (MPs) is one of the most serious environmental issues worldwide and has raised many concerns about their availability and hazards for aquatic biota. In addition, fish is an important source of protein for humans, hence, the accumulation, and toxic effects of the MPs in fish deserve special attention. This study aims to examine the ingestion, tissue accumulation and toxic effects of Polyvinyl chloride microplastics ((PVC)-MPs) in juvenile common carp.  Fluorescent-tagged (PVC)-MPs were found in various tissues of fish only after 4-5 days of exposure. The size of MPs showed a significant role in acute toxicity and mortality due to (PVC)-MPs. 100% mortality were observed after 7 and 10 days exposures to 1000 and 100 µg L-1 class A-(PVC)-MPs (100>µm) respectively, while 1000 µg L-1 of class A-(PVC)-MPs (300-1000 µm) killed only 16.6% of fish after ten days. Different grades of tissue damage were found in the gills, gut, and liver of fish in proportion to size, time, and concentration of (PVC)-MPs. Epithelial detachment, thinning of the bowel wall, and lesions of villi in the gastric wall were the dominant damages in the gastrointestinal tract. Gills also were affected in the form of necrosis, adhesion, and partial fusion of secondary lamellae. Hepatic damages (cellular necrosis and infiltration) were found only due to exposure of fish to class A-(PVC)-MPs. Altogether, these findings suggest that common carp intake significant levels of environmental microplastics (intentionally or accidentally), which seriously affect fish health and raise significant concerns about marine ecosystem health and seafood safety due to microplastic pollution.

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. 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. 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/m 3 while this was 0. 03 mg/m 3 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>0. 05). Conclusion: The NF membrane has high performance in sampling the crystalline silica dust from the air stream compared to commercial (PVC) membranes.

Membrane technology is known as one of the most efficient and extensive methods for oily wastewater treatment. In this research, Polyvinyl chloride ((PVC))-based mixed matrix membranes containing Uio66-NH2 nanoparticles and modified halloysite nanotubes (HNTs) were prepared using the phase inversion method. The synthesized membranes were characterized by field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) and contact angle measurement analysis. Then, the effect of these nanoparticles was investigated for oil/water emulsion separation in the ultrafiltration process. To evaluate the prepared membranes, pure water flux, mean pore size, and oil separation ultrafiltration tests were performed. The results exhibited that addition of HNTs to the casting solution enhanced the pure water flux about up to 4 folds. Overall experimental results showed that due to the uniform distribution of halloysite nanotubes in sample 2, water contact angle decreased from 81° to 72°. UF results confirmed that sample 2 had the potential of rejecting 97% of sunflower oil.

Organic stabilizers have been investigated as thermal stabilizers for rigid Polyvinyl chloride ((PVC)) at 180°C in inert atmosphere by measuring the rate of dehydrochlorination and changes in intrinsic viscosity, UV absorption spectra, FT-IR spectra and levels of unsaturation in the degraded polymer samples have been used to assess the effects of the materials on the degraded polymer. Theirs stabilizing efficiencies are based on measuring the length of the induction period (TS), the period during which no detectable amounts of HCl gas could be observed, and also from the rate of the dehydrochlorination as measured by bromometry titration on the one hand, and the extent of discoloration of the degraded polymer samples on the other. The results revealed the greater stabilizing efficiencies of the investigated materials as shown by their longer induction periods (TS) and by the lower dehydrochlorination rate in relation to blank (PVC). The stabilizer efficiency attributed to the replacement of the labile chlorine on the (PVC) chains by a relatively more thermally stable aromatic and aliphatic moiety. A radical mechanism for the stabilizing action of the investigated stabilizers is offered. A synergistic effect achieved when the material under investigation were blended in 1:1 weight ratio with either. The results reveal that mixing of the stabilizers improves the TS values, the rate of dehydrochlorination and the extent of discoloration.

ypothesis: In this study, modification of Polyvinyl chloride ultrafiltration membrane was done and the modified membrane was used in the ultrafiltration process for oil-in-water separation. Methods: at first, (PVC) was dehydrochlorinated by sodium hydroxide. Then, the resulting dehydrochlorinated Polyvinyl chloride (DH(PVC)) was grafted by styrene monomer and in the final step the grafted styrene was sulfonated by sulfuric acid. Ultrafiltration membranes were fabricated from (PVC), DH(PVC), styrene-grafted dehydrochlorinated Polyvinyl chloride and sulfonated polymer by phase separation method and were evaluated, using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and pure water permeation flux, determination of mean pore size, porosity and water contact angle tests. Findings: The presence of grafted functional groups was confirmed by FTIR spectra. SEM images showed that all the membranes had fingerlike pores and the difference in shape of the pores was due to the thermodynamic instability and viscosity of the polymer solutions. Due to the higher hydrophilicity of the polymer, the sulfonated membrane showed significant increase in pore size and pure water flux, compared to other membranes. The DH(PVC) membrane showed the lowest contact angle because of the detachment of chlorine as a hydrophobic agent, but for the other membranes there was little difference in their contact angles which could be related to the surface roughness. Subsequently, the oil/water separation experiments were performed by the membranes. The modified membranes showed good performance in the separation of oil and water and had less fouling than the (PVC) membrane. The rejection of oil particles was 100% for all membranes except the sulfonated membrane. The rejection of oil particles by the sulfonated membrane decreased, because of the higher pore size and significant increase in the flux.

The first purpose of this study is to investigate different methods of making viscous cellulose (in non-aqueous solvent) and strengthening tissue by cross-linking synthesis. The second goal is coupling with (PVC). To coat viscovellulose on Polyvinylchloride ((PVC)) surface in this study, instead of water, organic solvents as ethylenediamine and ethylene glycol were used to synthesize viscous cellulose. In the first method, gelatinization of cellulose was performed in ethylene glycol solvent and cellulose tissue was reinforced with ester crosslink by additives such as phthalic anhydride and Polyvinyl alcohol. In the second method, cellulose was aminolyzed in ethylenediamine and an amide cross-link was formed by using terephthalic acid. In the third method, cellulose acetate tissue was reinforced with Polyvinyl acetate and borax. Finally; it was rubberized with acetone solvent. In the final step, the viscose cellulose samples of each method were coated with a layer of (PVC) paste. To compare the quality of coupling methods, the tensile test and moisture absorption test were used. Based on the obtained results, the first (ester crosslink) and second method (amide crosslink) had better tensile strength (with tensile device) and moisture absorption (with volatile meter) was more than the others. The tensile strength of the first method and its moisture absorption was more than other methods. Also, intrinsic viscosity [η ] of viscocellulose: (PVC) paste (1: 1ratio) showed that the third method (cellulose acetate and Polyvinyl acetate paste) has the highest homogeneity and adhesion with (PVC) paste. The advantage of these methods is that for the synthesis of viscous cellulose, ethylene glycol solvent is used instead of water solvent and for activation energy, a microwave beam is used instead of heater heat. The importance of microwave beams for this research method is proved by the DSC method.

The effects of two different solvents of dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP) were investigated on the properties and performance of the neat and E(PVC)/nano-boehmite nanocomposite membranes. Boehmite nanoparticles were embedded into the membranes structure to improve their performance. Water contact angle, EDX, SEM, and AFM analyses were used to inspect the hydrophilicity, surface roughness, membrane morphology, and boehmite nanoparticles dispersion in the membranes structures, respectively. The optimum amounts of 1 wt% and 0. 75 wt% of the boehmite nanoparticles were obtained for the E(PVC)-based nanocomposite membranes prepared in different solvents of DMAc and NMP, respectively. It indicated that the optimum amount of nano-boehmite that promoting the properties of the membranes was depended on the type of solvent. In comparison with the neat membranes, the modified ones fabricated in DMAc and NMP solvents, using optimum concentrations of boehmite nanoparticles showed growth of 61. 7% and 66% in the fluxes of pure water, correspondingly and exhibited a significant improvement in the permeability. The value of BSA protein rejection for all of the E(PVC)-based membranes was higher than 98% which showed that the prepared membranes had excellent separation performance. The membranes fabricated in NMP solvent in the presence of the optimum amount of boehmite nanoparticles demonstrated the higher improvement in anti-fouling property and fouling resistance. Finally, it can be concluded that NMP solvent showed better performance in comparison with DMAc solvent for the improvement of the E(PVC)/nano-boehmite nanocomposite ultrafiltration membranes properties.

Considering the water quality problems and the strict laws established for drinking water treatment, the need to use more effective and economical methods to remove water pollutants is felt. Meanwhile, the use of membrane processes is considered one of the most important methods to remove pollutants as best as possible. Based on this, in the current research, microporous Polyvinyl chloride ((PVC)) membranes containing titanium dioxide (TiO2) nanoparticles were made using the nonsolvent induction phase separation method for use in humic acid separation as a model of polluted water. The obtained results showed that the membrane containing 3 wt% of nanoparticles has the highest pure water permeability with a value of 146. 2 l/m2h. Also, the analysis of the results of humic acid rejection showed that the membrane with 2 wt% of nanoparticles with the smallest average radius of the surface pores had the highest separation efficiency with a value of 80%.

In this research, a method based on the vacuum infusion process is proposed for making sandwich panels used in the marine industry. The mechanical properties of the product made with this method have been significantly improved compared to the adhesive bonding method, and also from an economic point of view, it’s cost-effective to use this method. In this method, the construction of face-sheets and their adhesion to the core is done in a single step, which results in some benefits such as reducing construction costs, increasing the production speed and improving the quality of the face-sheets adhesion to the core. According to the intended application, i. e. application in the marine industry, the core is made of grooved Polyvinyl chloride ((PVC)) foam and the face-sheets are made of glass/vinylester, which are well-known materials in the marine industry. The mechanical properties of the sandwich panel made by the proposed method have been investigated in both bending and compression loading. The results indicate that in the product made with the proposed method, the bending strength has increased by 78%, the compressive strength has increased by 92%, and the energy absorption has increased by 101% compared to the sandwich panel made by adhesive bonding method. The main factor in improving the mechanical properties of this product is the creation of a network of resin in the empty space of the grooves, which creates a structure similar to the foam filled honeycomb cores and strengthens the core, especially in the thickness direction.