Production Of PVC Research Articles

Hydrothermal dechlorination strategy for high-quality oil recovery from polyvinyl chloride

The global production of PVC is around 3.5 million tons each year. Unfortunately, the disposal of PVC waste releases toxic substances such as hydrochloric acid, polychlorinated dioxins, and furans, which can harm the environment. Therefore, there is an urgent need for a safe and environmentally friendly thermochemical treatment method that reduces the damage caused by HCl gas produced during PVC pyrolysis and improves the quality of pyrolysis oil. Hydrothermal treatment technology is one of the potential dechlorination strategies for PVC. However, its efficiency is reduced in the supercritical region, while the additives used result in secondary pollution and increased operating costs. This study is pioneering in its approach, aiming to produce high-quality oil with reduced chlorine through low-temperature hydrothermal treatment of PVC, all without additives. The results are promising, indicating that by administering steam at 250 °C with a 2.0–3.0 g-steam/g-feed ratio, we can significantly reduce chlorine content to 0.13 % while achieving an oil yield of up to 14.9 % from PVC. The hydrothermal process can reduce CO2 emissions by 15–43 % compared to pyrolysis methods, providing a simultaneous opportunity for carbon neutrality and resource recovery.

Evaluation of some oncomarkers and cytokines in vinyl chloride workers

Currently, there is a serious problem of the risk of developing oncopathology in chemical enterprises. Numerous workers in the chemical industry, including vinyl chloride and polyvinyl chloride (VC and PVC), are exposed to a complex of chemical compounds that, among other things, have carcinogenic effects and affect many body systems. The immune system has the ability to recognize malignant cells with subsequent activation and hyperactivation of immune responses, including cytokine production. To date, the details of cytokine control and, moreover, the ways of manipulating the antitumor immune response remain insufficiently studied.
 The study aims to evaluate changes in serum concentrations of certain cancer markers, cytokines and their relationships in highly trained vinyl chloride production workers.
 The authors have determined serum concentrations of cancer markers (CA 19-9; CEA) and interleukins (IL-1β, IL-2, IL-4, IL-8, TNF-α, INF-γ) using the method of solid-phase enzyme immunoassay.
 As a result of the study, the researchers found that the highest concentrations of carbohydrate antigen (CA 19-9) are characteristic of trained workers, and when analyzing their level of embryonic cancer antigen (CEA), its tendency to increase attracts attention, which significantly increases the likelihood of cancer pathology in workers. Also, in most workers of this production, we observed hyperproduction of IL-4, IL-8, TNF-α, INF-γ against the background of a decrease in IL-1β and IL-2. At the same time, an increase in the concentration of CA 19-9 was accompanied by a decrease in the levels of IL-8 and INF-γ, which may lead to the preservation of cancer risks.
 Thus, the assessment of changes in the content of markers of oncopathology, inflammatory mediators and their relationships among workers in the production of VC and PVC indicates and confirms the role of violations of the mechanisms of immunoregulation underlying the formation of various pathologies, including oncological ones. Further study of the mechanisms of cytokine regulation of the antitumor immune response will contribute to improving the methods of early diagnosis and prevention of disorders in the body of workers at carcinogenic enterprises.
 Ethics. The study was conducted in compliance with Ethical standards in accordance with the Helsinki Declaration of the World Medical Association.

In situ formed poly(ε-caprolactone) as a novel non-toxic plasticizer of poly(vinyl chloride)

Poly(vinyl chloride) (PVC) is the third most produced synthetic polymer in the world, irreplaceable in many applications including medical ones. The production of soft PVC presents a problem with volatile low-molecular plasticizers that can be harmful to human health. Therefore, they are often replaced with polymeric plasticizers, which are less effective and require higher processing temperature, however. In this work, we have studied a specific method of PVC plasticization consisting in the mixing of PVC with monomeric ε-caprolactone in a closed system. During thermal treatment of the mixture, in situ polymerization of the ε-caprolactone occurs, initiated by a tin stabilizer of PVC present in the mixture, which results in the formation of poly(ε-caprolactone), a non-toxic and bio-degradable polymeric plasticizer with various molar mass. In this way, a stable plasticized PVC material can be obtained, the thermal stability, softening range and mechanical properties of which correspond to the use of conventional plasticizers.

Evaluation of environmental impacts in PVC sector: the case of Turkey

ABSTRACT This study aims to evaluate the environmental impacts of PVC and provide recommendations to the industry to increase sustainability. The analysis first takes into account the effects at the product level, then moves on to the national level. According to the findings, total global warming potential (GWP) is estimated at 3 kg CO2 eq./kg PVC. The raw material supply stage is the most significant hotspot for all environmental impacts. The emissions and energy consumption associated with the production of PVC have been significantly reduced by increasing the recycling rate. The total annual GWP of the PVC profile sector in Turkey is estimated at around 1294 kt CO2 eq., which corresponds to nearly 0.3% of the country’s total greenhouse gas emissions. Policymakers, construction companies, PVC manufacturers, and users will be interested in the findings of this paper, which will allow them to make more informed decisions about the plastic industry.

A Sustainable Integration Approach of Chlor-Alkali Industries for the Production of PVC and Clean Fuel Hydrogen: Prospects and Bangladesh Perspectives

The chlor-alkali industries produce caustic soda (NaOH), chlorine (Cl2), and hydrogen (H2) as primary products. In 2021, the global chlor-alkali market was valued at $63.2 billion. The article evaluates the global aspects of chlor-alkali industries and prospects for Bangladesh. The current production capacity of NaOH from the chlor-alkali industries in Bangladesh is around 282,150 metric tons/year (MT/y). The by-products, chlorine (Cl2) of 250,470 MT/y and hydrogen (H2) of 7055 MT/y, are produced domestically. The local demand of Cl2 is 68,779 MT/y. However, there are no systematic utilizations of the residual Cl2 and vented H2, which threatens the sustainability of the chlor-alkali industries. The article prefigures that a 150,000 MT/y PVC plant can utilize 45.2 % of residual Cl2 of chlor-alkali plants, which would be an economical and environmental milestone for Bangladesh. The residual Cl2 can earn revenue of 908 million USD/y, which can be utilized to import ethylene. For the sustainable utilization of vented H2, production of H2O2, fuel cell electric vehicle (FCEV) and H2 fuel-cell-based power plant are the feasible solutions. Thus, for the long-term growth of the chlor-alkali industry in Bangladesh and other developing countries, systematic utilization of Cl2 and H2 is the only feasible solution.

Reutilization of melamine‐formaldehyde foam wastes: Removing Sn2+ in simulated tin‐containing wastewater to transform a fire hazard suppressant of flexible poly(vinyl chloride)

AbstractMelamine‐formaldehyde (MF) foam has wide applications due to good flame retardancy, excellent sound absorption, and high thermal stability. However, the recycling of MF foam wastes remains a challenge due to its thermosetting nature. Here, we demonstrate a new strategy for discarded foams as solid adsorbents for removing tin ions in simulated tin‐containing wastewater. Results showed that the removal rate of tin in simulated wastewater is as high as 99.996%. Moreover, after simple calcination, as‐obtained products can be used as high‐efficiency flame retardants for flexible poly(vinyl chloride) (PVC), reducing the peak of heat release rate and total smoke production of PVC by 51.8% and 45.8%, respectively, under the condition of 2.5 wt.% addition. In short, this strategy successfully converted MF foam and tin wastewater to valuable flame retardants, opening the way for the environmentally friendly recycling of MF waste and the simultaneous treatment of tin‐containing wastewater.

Importance of Recycling the Waste-Cables Containing Copper and PVC

Abstract Urbanization, development of economy, increasing population and improved living standards and lifestyle have caused a sharp growth in waste. Inappropriate or inefficient waste disposal techniques can cause serious air, soil, and groundwater pollution, which subsequently can negatively affect the urban environment and threaten the health of residents. The goal of waste management is to move to a circular economy in which waste does not exist. If there is no possible way to reduce or reuse waste, the best solution is recycling it. Recycling brings abundant benefits on the economic and ecological levels levels, and helps reduce overall human health risk of adverse impacts. Recycling of the waste-cables which contain PVC and copper replaces the production of virgin PVC and mining of copper from copper ore, it reduces landfill solid waste pressures, saves energy and water sources, reduces emissions to environment, and also reduces negative impacts from improperly dispose of waste, etc. This paper presents an overview of recycling techniques for the waste-cables containing copper as a core and polyvinyl chloride as an insulating layer or sheath. It also lists advantages and disadvantages of these techniques and importance of recycling this type of waste.

Innovative oligomeric poly(vinyl chloride) plasticizers for specialized applications

The purpose of the work was to determine the properties of poly(vinyl chloride) (PVC) plasticized with a new linear and oligomeric terephthalic acid esters and aliphatic acids in terms of their application as an innovative non-phthalate plasticizers. On the basis of analysis of PVC grain swelling shows that these compounds have plasticizing properties. Plastographometric tests were performed, the glass transition temperature and thermal stability time were analyzed. The mass flow rate (MFR) and mechanical properties of plasticized PVC was determined. Based on the analysis of the results obtained, it can be concluded that both assessed oligoesters can be successfully used for the production of plasticized PVC with utility indicators similar to those of plasticized PVC produced so far.

Effects of polyether titanate coupling agent on the flame retardancy and mechanical properties of soft poly(vinyl chloride)/basic magnesium carbonate composites

AbstractIn this paper, a new polyether titanate coupling agent (Ti4000) was used to modify basic magnesium carbonate (BMC), and Ti4000 modified BMC (Ti4000‐BMC) was characterized by X‐ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy. Then, PVC composites were prepared by adding BMC or Ti4000‐BMC into soft PVC matrix via melt blending, and their flame retardancy was examined by limiting oxygen index (LOI), UL‐94 test, and cone calorimeter test. The results show that BMC can effectively improve flame resistance and suppress smoke production of pure soft PVC. As a result, the LOI is increased from 23.9% for pure soft PVC to 29.2% for Ti4000‐BMC/PVC composite with 50 phr Ti4000‐BMC (50%Ti4000‐BMC/PVC), and the composite passes the V0 rating in UL‐94 test, the peak heat release rate, total heat release, peak smoke production rate, and total smoke production are decreased from 343.10 kW/m2, 94.50 MJ/m2, 0.17 m2/s, and 27.20 m2/kg for pure soft PVC to 234.20 kW/m2, 70.20 MJ/m2, 0.02 m2/s, and 2.30 m2/kg for 50%Ti4000‐BMC/PVC composite, respectively. The analysis of char residues suggests that Ti4000‐BMC/PVC composites form the most compact char layer structure, indicating that the soft PVC composites show better char forming ability. In addition, the yield strength is increased from 4.4 MPa for pure soft PVC to 12.9 MPa for 50%Ti4000‐BMC/PVC composite, with an increase of 193.2%, and it shows good reinforcement effect on the soft PVC matrix.

Job security in a packaging and distribution of hydrochloric acid company

Hydrochloric acid is a chemical compound with broad applications in industry, chemistry, mainly used for the manufacture of agrochemicals, veterinary products, production of PVC, the process of demineralization of water, activation of oil fields, process of tanning skins, process of stamping in the textile industry, production of pharmaceuticals as well as applications in the food industry as an additive in the manufacture of gelatin and sugar. In recent years in Mexico, the chemical industry has held between the third and fourth place in the value of GDP is a 10.7% of this (INEGI, 2015). The growth of this industry every year, explains the increase in the demand for the product of the study dedicated to the purchase, storage, packaging and distribution of hydrochloric acid and muriatic. This company raises the need to distribute their areas of production, optimizing the working conditions and the need to expand to implementing a better distribution of plant that guarantees the security of the worker and increase its production capacity and competitiveness.

ASPECTS OF DETERMINATION OF THIODIACETIC ACID IN URINE AS BIOMARKERS FOR INDUSTRIAL EXPOSURE TO VINYL CHLORIDE AND 1,2 -DICHLOROETHANE

There was developed and certified the analytical method for the determination of thiodiacetic acid in the urine in the range of from 0.1 to 10µg/cm3. The sample preparation is based on the execution of derivatization of methanol in the presence of boron trifluoride (10 wt%) followed by liquid-liquid microextraction with dimethyl ester the acid. Derivatization reaction was carried out for 15 min at 80°C. Gas chromatographic analysis was performed on a capillary column HP-5ms under the temperature gradient and splitless modes. Mass spectrometric detection occurred during the registration of selective ions (SIM). Identification of derivatives of thiodiacetic acid on the mass chromatograms was carried out by the absolute retention time (10.36 min) and the ratio of peak intensities of detected ions. The random error in the determination of component and the accuracy of the expanded uncertainty does not exceed 2 and 25%, respectively. There was made a comparative evaluation of the content of thiodiacetic acid in the urine of workers of main shops production of PVC with persons of the control group, not involved in the production. The results can be used for the identification of the fact of the exposure to toxic substances and assessment of the level of exposure and biomonitoring, as a component of health interventions for the prevention of occupational and production-related diseases.

The block combustion, high char residues and smoke restrain effect of nano-FeSnO(OH)5 on polyvinyl chloride

Nanoscale and cubic-shaped FeSnO(OH)5 (ITOH) flame retardant was synthesized by co-precipitation method and characterized by X-ray diffraction and transmission electron microscopy (TEM). The blank poly(vinyl chloride) (PVC0) and flexible PVC/ITOH composites were investigated by the limiting oxygen index (LOI), cone calorimetric test, tensile test and thermogravimetric analysis. The results showed that compared with PVC0, the LOI of PVC sample treated with 15 phr ITOH (PVC15) increases by 7.7%, and ITOH could more effectively promote the dehydrochlorination reaction of PVC. The flame of PVC15 disappeared for up to 165 s when it burned for 120 s, which significantly reduced the total heat release and total smoke production of PVC. This phenomenon not only can effectively prevent the proliferation of fire, but also facilitates the evacuation of people in the event of a fire. Lewis acid FeCl2 and FeOCl, assigned by the Fe2p spectra of char residue, could effectively catalyze the cross-linking of PVC into carbon.

Bio-inspired dechlorination of poly vinyl chloride

Production of PVC through petroleum may involve chlorine as an element for the activity on microscopic (i.e., atomic or molecular) level and the same mechanism may involve for its dechlorination. Oxychlorination assisted pyrolysis is an important reaction towards the synthesis of PVC and the reverse reaction is possible for its degradation. Ethylene carbonate (EC) with hydroxyethyl carbamate (ED) supports the microbial susceptibility of PVC. EC with ED can be synthesized through an inexpensive route of using ethylene glycol (EG) with urea. Pseudomonas sp. and Aspergillus sp. are found to be responsible microbe for the resultant dechlorination. This approach provides a novel hybrid combination for PVC dechlorination and proposes EC-ED combination as a new green bio-inspiring reagent.

Synthesis of amphiphilic PVC-b-poly(hydroxypropyl acrylate) (PHPA)-b-PVC block copolymers with low PHPA contents and different molecular weights by (Single Electron Transfer)-(Degenerative Chain Transfer) living radical polymerization

The aim of this work was to synthesize new amphiphilic block copolymers, based on poly(vinyl chloride) (PVC) and containing poly(hydroxypropyl acrylate) (PHPA), by using the controlled/“living” radical polymerization (CLRP) method. Various block copolymers containing a small proportion of PHPA were prepared, each having a different molecular weight. The technique used was the same as that employed in the production of commercial PVC made by free-radical polymerization. The materials were characterized in terms of their molecular structure, morphology, particle size, and surface and thermal properties. The CLRP preparation of block copolymers that are based on PVC and have low contents of other monomer units opens the possibility of synthesizing new materials whose properties are close to those of PVC but have new properties that may considerably enhance their performance. The incorporation of small amounts of PHPA into PVC block copolymers provided greater surface hydrophilicity and improved thermal stability while maintaining relevant processing properties, such as particle size and average molecular weight, so that they close to those of conventional PVC homopolymers. J. VINYL ADDIT. TECHNOL., 19:157-167, 2013. © 2013 Society of Plastics Engineers

Scaling-up of poly(vinyl chloride) prepared by single electron transfer degenerative chain transfer mediated living radical polymerization in water media: 1) Low molecular weight. Kinetic analysis

This paper reports the kinetic study of the scale-up for the production of PVC by using a single electron transfer degenerative chain transfer mediated living radical polymerization in water media in a 150 L reactor. It presents the study of several parameters that have an important role in the reaction kinetics (initiators, suspending agents, catalysts and temperature). The thermal stability of the materials was also assessed using a standard discoloration test employed by the PVC industry. The results show the possibility of scaling-up this new and promising technology using the same facilities as the conventional free radical polymerization process with results closely matching those obtained in 50 mL glass reactors.

Continuous extrusion production of microcellular rigid PVC

AbstractThis study examined the effect of Poly[vinyl chloride] (PVC) formulation on the cell morphology and density of rigid PVC foamed with supercritical CO2 in a continuous extrusion process. Cell morphology and the density of foamed samples were controlled by blending two acrylic‐based processing aids (all‐acrylic foam modifier K‐400 and acrylic‐based impact modifier KM‐334), using a mixture design. The effect of blend ratios on the fusion and die swell behaviors of PVC was investigated by means of a torque rheometer and on a single‐screw extrusion capillary rheometer, respectively. Fusion was promoted as the relative amount of the all‐acrylic foam modifier increased in the blends. Similarly, the elastic constant of PVC, derived from the linear relationship between the die swell and apparent shear stress, increased upon increasing the relative amount of the all‐acrylic foam modifier in the blends, thus suggesting an increase in the melt elasticity of PVC. Microcellular rigid PVC foams with densities of approximately 0.15 g/cm3 and a tenfold volume expansion were produced. An optimum ratio of impact modifier to all‐acrylic foam modifier of 1:3 was found to maximize the foam expansion. Using impact modifier alone or all‐acrylic foam modifier alone yielded expansions considerably lower than that achieved with the 1:3 blend. The experimental results indicated that fusion is not the only criterion to control the cell morphology and density achieved in microcellular rigid PVC foams. The melt must have a viscosity low enough to allow bubble formation and growth, as well as elasticity high enough to prevent cell coalescence. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers

Eco-profiles and environmental declarations for PVC

The 'eco-profiles' (cradle to grave life cycle inventories) of the major thermoplastics published by PlasticsEurope since the early 1990s provide a recognised reference for environmental impacts of plastics up to and including resin production. The suspension and emulsion PVC eco-profiles were fully updated in 2005, on the basis of 2004 averages collected in the plants of ECVM members and sister companies. The results are very robust, covering more than 90% of West European production of VCM and PVC. The results show a decrease in both energy consumption and CO2 emissions. Many other emissions, related to energy production (SO2, NOx) or directly related to VCM and PVC processing (e.g. VCM), also decreased very significantly. The data obtained have been aggregated into environmental declarations for suspension and emulsion PVC, the first such declarations available for polymers. These documents provide a compact summary of the main impact categories as well as other relevant information for downstream users.

Additives aid push for rigid PVC in construction

Many different additives are used in the production of rigid PVC - solving a number of problems particularly in the construction industry. Jennifer Markarian reviews some of the trends in heat stabilizers, impact modifiers, flame retardants, lubricants and processing aids for use in rigid PVC.

Recent technical trends in the market for E-PVC in Europe

The development of new emulsion resins (also known as dispersion or paste resins) continues despite dramatic changes in the applications sector for these types of resins. Suppliers of such resins still find the need to innovate constantly in order to maintain a market position and to both lead and follow the technical developments in a dynamic market place. The purpose of the present study is to (i) review the history of the developments in this technology sector, (ii) show how polymer technology has adapted to meet new technical demands of key European applications sectors, even when these technical demands in different markets are often opposed to each other, and (iii) make some qualified predictions for the future developments in the dispersion resin market in Europe. The present study will include descriptions of the principal technologies for the production of Emulsion PVC (E-PVC) resins, namely emulsion (batch and continuous), microsuspension and 'mini-emulsion' and the potential benefits of each of these technologies will be compared. How these technologies can be developed to add value to the principal market sectors consuming them – flooring, wallcoverings, synthetic leather, coated fabrics and sealants – will be described. How these will develop over the coming years, and how an ever increasing regulatory framework (both for resin producers and for vinyl formulators) can be accommodated, will also be discussed.

Non‐transition metal‐catalyzed living radical polymerization of vinyl chloride initiated with iodoform in water at 25 °C

AbstractNon‐transition metal‐catalyzed living radical polymerization (LRP) of vinyl chloride (VC) in water at 25–35 °C is reported. This polymerization is initiated with iodoform and catalyzed by Na2S2O4. In water, S2Odissociates into SOthat mediates the initiation and reactivation steps via a single electron transfer (SET) mechanism. The exchange between dormant and active propagating species also includes the degenerative chain transfer to dormant species (DT). In addition, the SO2released from SOduring the SET process can add reversibly to poly(vinyl chloride) (PVC) radicals and provide additional transient dormant ∼SOradicals. This novel LRP proceeds mostly by a combination of competitive SET and DT mechanisms and, therefore, it is called SET‐DTLRP. Telechelic PVC with a number‐average molecular weight (Mn) = 2,000–55,000, containing two active ∼CH2CHClI chain ends and a higher syndiotacticity than the commercial PVC were obtained by SET‐DTLRP. This PVC is free of structural defects and exhibits a higher thermal stability than commercial PVC. SET‐DTLRP of VC is carried out under reaction conditions related to those used for its commercial free‐radical polymerization. Consequently, SET‐DTLRP is of technological interest both as an alternative commercial method for the production of PVC with superior properties as well as for the synthesis of new PVC‐based architectures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6267–6282, 2004