Polyvinyl chloride (alternatively: poly(vinyl chloride),[6][7] colloquial: vinyl[8] or polyvinyl; abbreviated: PVC[8]) is the world's third-most widely produced synthetic polymer of plastic (after polyethylene and polypropylene). About 40 million tons of PVC are produced each year.[9]
For more information, please visit our website.
PVC comes in rigid (sometimes abbreviated as RPVC) and flexible forms. Rigid PVC is used in construction for pipes, doors and windows. It is also used in making plastic bottles, packaging, and bank or membership cards. Adding plasticizers makes PVC softer and more flexible. It is used in plumbing, electrical cable insulation, flooring, signage, phonograph records, inflatable products, and in rubber substitutes.[10] With cotton or linen, it is used in the production of canvas.
Polyvinyl chloride is a white, brittle solid. It is soluble in ketones, chlorinated solvents, dimethylformamide, THF and DMAc.[11]
PVC was synthesized in by German chemist Eugen Baumann after extended investigation and experimentation.[12] The polymer appeared as a white solid inside a flask of vinyl chloride that had been left on a shelf sheltered from sunlight for four weeks. In the early 20th century, the Russian chemist Ivan Ostromislensky and Fritz Klatte of the German chemical company Griesheim-Elektron both attempted to use PVC in commercial products, but difficulties in processing the rigid, sometimes brittle polymer thwarted their efforts. Waldo Semon and the B.F. Goodrich Company developed a method in to plasticize PVC by blending it with various additives,[13] including the use of dibutyl phthalate by .[14]
Polyvinyl chloride is produced by polymerization of the vinyl chloride monomer (VCM), as shown.[15]
About 80% of production involves suspension polymerization. Emulsion polymerization accounts for about 12%, and bulk polymerization accounts for 8%. Suspension polymerization produces particles with average diameters of 100–180 μm, whereas emulsion polymerization gives much smaller particles of average size around 0.2 μm. VCM and water are introduced into the reactor along with a polymerization initiator and other additives. The contents of the reaction vessel are pressurized and continually mixed to maintain the suspension and ensure a uniform particle size of the PVC resin. The reaction is exothermic and thus requires cooling. As the volume is reduced during the reaction (PVC is denser than VCM), water is continually added to the mixture to maintain the suspension.[9]
PVC may be manufactured from ethylene, which can be produced from either naphtha or ethane feedstock.[16]
The polymers are linear and are strong. The monomers are mainly arranged head-to-tail, meaning that chloride is located on alternating carbon centres. PVC has mainly an atactic stereochemistry, which means that the relative stereochemistry of the chloride centres are random. Some degree of syndiotacticity of the chain gives a few percent crystallinity that is influential on the properties of the material. About 57% of the mass of PVC is chlorine. The presence of chloride groups gives the polymer very different properties from the structurally related material polyethylene.[17] At 1.4 g/cm3, PVC's density is also higher than structurally related plastics such as polyethylene (0.88–0.96 g/cm3) and polymethylmethacrylate (1.18 g/cm3).
About half of the world's PVC production capacity is in China, despite the closure of many Chinese PVC plants due to issues complying with environmental regulations and poor capacities of scale. The largest single producer of PVC as of is Shin-Etsu Chemical of Japan, with a global share of around 30%.[16]
The product of the polymerization process is unmodified PVC. Before PVC can be made into finished products, it always requires conversion into a compound by the incorporation of additives (but not necessarily all of the following) such as heat stabilizers, UV stabilizers, plasticizers, processing aids, impact modifiers, thermal modifiers, fillers, flame retardants, biocides, blowing agents and smoke suppressors, and, optionally, pigments.[18] The choice of additives used for the PVC finished product is controlled by the cost performance requirements of the end use specification (underground pipe, window frames, intravenous tubing and flooring all have very different ingredients to suit their performance requirements). Previously, polychlorinated biphenyls (PCBs) were added to certain PVC products as flame retardants and stabilizers.[19]
Among the common plastics, PVC is unique in its acceptance of large amounts of plasticizer with gradual changes in physical properties from a rigid solid to a soft gel,[20] and almost 90% of all plasticizer production is used in making flexible PVC.[21][22] The majority is used in films and cable sheathing.[23] Flexible PVC can consist of over 85% plasticizer by mass, however unplasticized PVC (UPVC) should not contain any.[24]
PVC properties as a function of phthalate plasticizer level[24] Plasticizer content (% DINP by weight) Specific gravity (20 °C) Shore hardnessThe most common class of plasticizers used in PVC is phthalates, which are diesters of phthalic acid. Phthalates can be categorized as high and low, depending on their molecular weight. Low phthalates such as Bis(2-ethylhexyl) phthalate (DEHP) and Dibutyl phthalate (DBP) have increased health risks and are generally being phased out. High-molecular-weight phthalates such as diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) are generally considered safer.[22]
While DEHP has been medically approved for many years for use in medical devices, it was permanently banned for use in children's products in the US in by US Congress;[25] the PVC-DEHP combination had proved to be very suitable for making blood bags because DEHP stabilizes red blood cells, minimizing hemolysis (red blood cell rupture). However, DEHP is coming under increasing pressure in Europe. The assessment of potential risks related to phthalates, and in particular the use of DEHP in PVC medical devices, was subject to scientific and policy review by the European Union authorities, and on 21 March , a specific labeling requirement was introduced across the EU for all devices containing phthalates that are classified as CMR (carcinogenic, mutagenic or toxic to reproduction).[26] The label aims to enable healthcare professionals to use this equipment safely, and, where needed, take appropriate precautionary measures for patients at risk of over-exposure.[27]
BaZn stabilisers have successfully replaced cadmium-based stabilisers in Europe in many PVC semi-rigid and flexible applications.[28]
In Europe, particularly Belgium, there has been a commitment to eliminate the use of cadmium (previously used as a part component of heat stabilizers in window profiles) and phase out lead-based heat stabilizers (as used in pipe and profile areas) such as liquid autodiachromate and calcium polyhydrocummate by . According to the final report of Vinyl ,[29] cadmium was eliminated across Europe by . The progressive substitution of lead-based stabilizers is also confirmed in the same document showing a reduction of 75% since and ongoing. This is confirmed by the corresponding growth in calcium-based stabilizers, used as an alternative to lead-based stabilizers, more and more, also outside Europe.[9]
Some of the most crucial additives are heat stabilizers. These agents minimize loss of HCl, a degradation process that starts above 70 °C (158 °F) and is autocatalytic. Many diverse agents have been used including, traditionally, derivatives of heavy metals (lead, cadmium). Metallic soaps (metal "salts" of fatty acids such as calcium stearate) are common in flexible PVC applications.[9]
PVC is a thermoplastic polymer. Its properties are usually categorized based on rigid and flexible PVCs.[30]
Property Unit of measurement Rigid PVC Flexible PVC Density[31] g/cm3 1.3–1.45 1.1–1.35 Thermal conductivity[32] W/(m·K) 0.14–0.28 0.14–0.17 Yield strength[31] psi 4,500–8,700 1,450–3,600 MPa 31–60 10.0–24.8 Young's modulus[33] psi 490,000 — GPa 3.4 — Flexural strength (yield)[33] psi 10,500 — MPa 72 — Compression strength[33] psi 9,500 — MPa 66 — Coefficient of thermal expansion (linear)[33] mm/(mm °C) 5×10−5 — Vicat B[32] °C 65–100 Not recommended Resistivity[a][34] Ω m – Surface resistivity[a][34] Ω – –The heat stability of raw PVC is very poor, so the addition of a heat stabilizer during the process is necessary in order to ensure the product's properties. Traditional product PVC has a maximum operating temperature around 60 °C (140 °F) when heat distortion begins to occur.[35]
As a thermoplastic, PVC has an inherent insulation that aids in reducing condensation formation and resisting internal temperature changes for hot and cold liquids.[35]
Roughly half of the world's PVC resin manufactured annually is used for producing pipes for municipal and industrial applications.[36] In the private homeowner market, it accounts for 66% of the household market in the US, and in household sanitary sewer pipe applications, it accounts for 75%.[37][38] Buried PVC pipes in both water and sanitary sewer applications that are 100 mm (4 in) in diameter and larger are typically joined by means of a gasket-sealed joint. The most common type of gasket utilized in North America is a metal-reinforced elastomer, commonly referred to as a Rieber sealing system.[39]
PVC is often used as the insulating sheath on electrical cables. PVC is chosen because of its good electrical insulation, ease of extrusion, and resistance to burn.[40]
In a fire, PVC can form hydrogen chloride fumes; the chlorine serves to scavenge free radicals, making PVC-coated wires fire retardant. While hydrogen chloride fumes can also pose a health hazard in their own right, it dissolves in moisture and breaks down onto surfaces, particularly in areas where the air is cool enough to breathe, so would not be inhaled.[41]
PVC is widely and heavily used in construction and building industry,[9] For example, vinyl siding is extensively is a popular low-maintenance material, particularly in Ireland, the United Kingdom, the United States, and Canada. The material comes in a range of colors and finishes, including a photo-effect wood finish, and is used as a substitute for painted wood, mostly for window frames and sills when installing insulated glazing in new buildings; or to replace older single-glazed windows, as it does not decompose and is weather-resistant. Other uses include fascia, and siding or weatherboarding. This material has almost entirely replaced the use of cast iron for plumbing and drainage, being used for waste pipes, drainpipes, gutters and downspouts. PVC is known as having strong resistance against chemicals, sunlight, and oxidation from water.[42]
Polyvinyl chloride is formed in flat sheets in a variety of thicknesses and colors. As flat sheets, PVC is often expanded to create voids in the interior of the material, providing additional thickness without additional weight and minimal extra cost (see closed-cell PVC foamboard). Sheets are cut using saws and rotary cutting equipment.
Plasticized PVC is also used to produce thin, colored, or clear, adhesive-backed films referred to simply as "vinyl". These films are typically cut on a computer-controlled plotter (see vinyl cutter) or printed in a wide-format printer. These sheets and films are used to produce a wide variety of commercial signage products, vinyl wraps or racing stripes on vehicles for aesthetics or as wrap advertising, and general purpose stickers.[43]
PVC fabric is water-resistant, used for its weather-resistant qualities in coats, skiing equipment, shoes, jackets, and aprons.[44] The shoulders of donkey jackets are traditionally made out of PVC. Early high visibility clothing was also made of PVC
The two main application areas for single-use medically approved PVC compounds are flexible containers and tubing: containers used for blood and blood components, for urine collection or for ostomy products and tubing used for blood taking and blood giving sets, catheters, heart-lung bypass sets, hemodialysis sets etc. In Europe the consumption of PVC from medical devices is approximately 85,000 tons each year. Almost one third of plastic-based medical devices are made from PVC.[45]
PVC has been applied to various items such as: bottles,[46] packaging films,[46] blister packs,[46] cling wraps,[46] and seals on metal lids.
PVC may be extruded under pressure to encase wire rope and aircraft cable used for general purpose applications. PVC coated wire rope is easier to handle, resists corrosion and abrasion, and may be color-coded for increased visibility. It is found in a variety of industries and environments both indoor and out.[47]
Molded PVC is used to produce phonograph, or "vinyl", records. PVC piping is a cheaper alternative to metal tubing used in musical instrument making; it is therefore a common alternative when making wind instruments, often for leisure or for rarer instruments such as the contrabass flute. An instrument that is almost exclusively built from PVC tube is the thongophone, a percussion instrument that is played by slapping the open tubes with a flip-flop or similar.[48] PVC is also used as a raw material in automotive underbody coating.[49]
PVC can be usefully modified by chlorination, which increases its chlorine content to or above 67%. Chlorinated polyvinyl chloride, (CPVC), as it is called, is produced by chlorination of aqueous solution of suspension PVC particles followed by exposure to UV light which initiates the free-radical chlorination.[9]
Phthalates, which are incorporated into plastics as plasticizers, comprise approximately 70% of the US plasticizer market; phthalates are by design not covalently bound to the polymer matrix, which makes them highly susceptible to leaching. Phthalates are contained in plastics at high percentages. For example, they can contribute up to 40% by weight to intravenous medical bags and up to 80% by weight in medical tubing.[50] Vinyl products are pervasive—including toys,[51] car interiors, shower curtains, and flooring—and initially release chemical gases into the air. Some studies indicate that this outgassing of additives may contribute to health complications, and have resulted in a call for banning the use of DEHP on shower curtains, among other uses.[52]
In a joint Swedish-Danish research team found a statistical association between allergies in children and indoor air levels of DEHP and BBzP (butyl benzyl phthalate), which is used in vinyl flooring.[53] In December , the European Chemicals Bureau of the European Commission released a final draft risk assessment of BBzP which found "no concern" for consumer exposure including exposure to children.[54]
Lead compounds had previously been widely added to PVC to improve workability and stability but have been shown to leach into drinking water from PVC pipes.[55]
In Europe the use of lead-based stabilizers has been discontinued. The VinylPlus voluntary commitment which began in , saw European Stabiliser Producers Association (ESPA) members complete the replacement of Pb-based stabilisers in .[56][57]
In the early s, the carcinogenicity of vinyl chloride (usually called vinyl chloride monomer or VCM) was linked to cancers in workers in the polyvinyl chloride industry. Specifically workers in polymerization section of a B.F. Goodrich plant near Louisville, Kentucky, were diagnosed with liver angiosarcoma also known as hemangiosarcoma, a rare disease.[58] Since that time, studies of PVC workers in Australia, Italy, Germany, and the UK have all associated certain types of occupational cancers with exposure to vinyl chloride, and it has become accepted that VCM is a carcinogen.[9]
PVC produces HCl and carbon dioxide upon combustion.
Shanwei Dongze supply professional and honest service.
Studies of household waste burning indicate consistent increases in dioxin generation with increasing PVC concentrations.[59] According to the U.S. EPA dioxin inventory, landfill fires are likely to represent an even larger source of dioxin to the environment. A survey of international studies consistently identifies high dioxin concentrations in areas affected by open waste burning and a study that looked at the homologue pattern found the sample with the highest dioxin concentration was "typical for the pyrolysis of PVC". Other EU studies indicate that PVC likely "accounts for the overwhelming majority of chlorine that is available for dioxin formation during landfill fires."[59]
The next largest sources of dioxin in the U.S. EPA inventory are medical and municipal waste incinerators.[60] Various studies have been conducted that reach contradictory results. For instance a study of commercial-scale incinerators showed no relationship between the PVC content of the waste and dioxin emissions.[61][62] Other studies have shown a clear correlation between dioxin formation and chloride content and indicate that PVC is a significant contributor to the formation of both dioxin and PCB in incinerators.[63][64][65]
In February , the Technical and Scientific Advisory Committee of the US Green Building Council (USGBC) released its report on a PVC avoidance related materials credit for the LEED Green Building Rating system. The report concludes that "no single material shows up as the best across all the human health and environmental impact categories, nor as the worst" but that the "risk of dioxin emissions puts PVC consistently among the worst materials for human health impacts."[66]
In Europe the overwhelming importance of combustion conditions on dioxin formation has been established by numerous researchers. The single most important factor in forming dioxin-like compounds is the temperature of the combustion gases. Oxygen concentration also plays a major role on dioxin formation, but not the chlorine content.[67]
Several studies have also shown that removing PVC from waste would not significantly reduce the quantity of dioxins emitted. The EU Commission published in July a Green Paper on the Environmental Issues of PVC"[68]
A study commissioned by the European Commission on "Life Cycle Assessment of PVC and of principal competing materials" states that "Recent studies show that the presence of PVC has no significant effect on the amount of dioxins released through incineration of plastic waste."[69]
In Europe, developments in PVC waste management have been monitored by Vinyl ,[70] established in . Vinyl 's objective was to recycle 200,000 tonnes of post-consumer PVC waste per year in Europe by the end of , excluding waste streams already subject to other or more specific legislation (such as the European Directives on End-of-Life Vehicles, Packaging and Waste Electric and Electronic Equipment).[71]
Since June , it is followed by VinylPlus, a new set of targets for sustainable development.[72] Its main target is to recycle 800,000 tonnes per year of PVC by including 100,000 tonnes of "difficult to recycle" waste. One facilitator for collection and recycling of PVC waste is Recovinyl.[73] The reported and audited mechanically recycled PVC tonnage in was 568,695 tonnes which in had increased to 739,525 tonnes.[74]
One approach to address the problem of waste PVC is also through the process called Vinyloop. It is a mechanical recycling process using a solvent to separate PVC from other materials. This solvent turns in a closed loop process in which the solvent is recycled. Recycled PVC is used in place of virgin PVC in various applications: coatings for swimming pools, shoe soles, hoses, diaphragms tunnel, coated fabrics, PVC sheets.[75] This recycled PVC's primary energy demand is 46 percent lower than conventional produced PVC. So the use of recycled material leads to a significant better ecological footprint. The global warming potential is 39 percent lower.[76]
In November , one of the largest hospital networks in the US, Catholic Healthcare West, signed a contract with B. Braun Melsungen for vinyl-free intravenous bags and tubing.[77]
In January , a major US West Coast healthcare provider, Kaiser Permanente, announced that it will no longer buy intravenous (IV) medical equipment made with PVC and DEHP-type plasticizers.[78]
In , the U.S. Consumer Product Safety Commission (CPSC) arrived at a voluntary agreement with manufacturers to remove phthalates from PVC rattles, teethers, baby bottle nipples and pacifiers.[79]
Plasticized PVC is a common material for medical gloves. Due to vinyl gloves having less flexibility and elasticity, several guidelines recommend either latex or nitrile gloves for clinical care and procedures that require manual dexterity or that involve patient contact for more than a brief period. Vinyl gloves show poor resistance to many chemicals, including glutaraldehyde-based products and alcohols used in formulation of disinfectants for swabbing down work surfaces or in hand rubs. The additives in PVC are also known to cause skin reactions such as allergic contact dermatitis. These are for example the antioxidant bisphenol A, the biocide benzisothiazolinone, propylene glycol/adipate polyester and ethylhexylmaleate.[80]
According to Vinyl , the life cycle, sustainability, and appropriateness of PVC have been extensively discussed and addressed within the PVC industry.[81][82] In Europe, a VinylPlus Progress Report indicated that 731,461 tonnes PVC were recycled in , a 5% reduction compared to due to the COVID-19 pandemic.[83]
Academic research identifies plastic pipes as a significant source of microplastics (MP) and nanoplastics (NP) in potable water systems. An analysis by Świetlik and Magnucka of water and pipes taken from water-transmission systems in found that both PVC and PE pipes crack and peel “relatively quickly” as they age, due to interactions between the plastic materials with water and additives used for disinfection.
As the interior surfaces of these pipes degrade, they release particles of plastic into water. When people ingest the MP and NP flaking from plastic pipes, it adds to their already significant exposure to plastic pollution. Recent studies estimate that humans are exposed to up to 883 microplastic particles per day, primarily through drinking water.
Plastic debris in the environment has physical and chemical properties that can create serious health impacts. This report summarizes research on how plastic pipes shed MP and NP and reviews the effects that these particles can have on the gut, lungs, brain, and reproductive systems, along with risk factors for the spread of pathogens and disease.
The material properties of plastic make it susceptible to both natural and chemical aging processes. For plastic pipes, interaction with water and disinfection chemicals represents a significant source of aging effects, along with factors like heat and mechanical wear. Microbial activity represented an accelerant, with research finding that metabolic processes carried out by microorganisms that grow and coat the insides of pipes – known as biofilms – “aggravate the material degradation process” of plastic. Each of these aging factors changes the structure and properties of plastics, changing their structure and/or properties in ways that will be described later in this report.
To understand the phenomenon more completely, Świetlika and Magnucka examined mechanisms of MP and NP release from plastic pipes by sampling plastic water pipes from existing systems. They then scanned the pipes to assess “microdamage and exfoliation on the surface of polymers,” including “chemical and biological degradation processes on the interior surfaces of water pipes.” Their analysis showed “micro-damage and cracks” in the plastic pipes used most often for water distribution (PVC and PE) and that the degradation released more nanoplastics than microplastics.
Plastic pipes are made from resins derived from fossil fuels such as oil and gas. The chemical composition of common plastic piping materials – including polyvinyl chloride (PVC), polyethylene (PE), crosslinked polyethylene (PEX), and crosslinked polyvinyl chloride (CPVC) – varies significantly, however. The following sections of this report look at what we know about each of these plastics.
Pipes made of polyvinyl chloride (PVC) have strong and rigid walls, so they can be used in applications that softer, weaker plastics cannot. Main applications include water supply lines and drain/waste/vent applications.
Researchers analyzed microscopic images of PVC pipe showing extensive pitting and holes along with fine, torn plastic particles on the inner surface of the pipe walls. They found these wear patterns regardless of the pipe age or diameter, with “peeling and detachment of the polymeric material,” forming NP that were released into the distributed water.
Types of damage varied depending on the diameter of the pipe. Wider pipes mainly showed “deep pits around which peeling areas and plastic particles were visible.” By contrast, small-diameter pipes showed numerous particles and fragments of torn material. Since these smaller pipes are mainly found near the ends of water distribution networks, including within homes, they can “significantly” expose consumers to “unwanted microplastics… via tap water.”
The increased irregularity and porosity of the polymer was also found to harbor mineral deposits and dense biofilms. The growth and waste byproducts from microorganisms can biodegrade pipe structure and impact quality of distributed water.
Teams also identified other byproducts of PVC-water interactions in water, including the following:
Polyethylene (PE) pipes feature good material strength compared to other plastics but have a brittle structure that requires additional care to minimize risk of impact damage.
Further, expansion and contraction of PE due to temperature fluctuations is significant over long pipe runs, requiring allowances in the design to ensure system integrity. This pipe is often used for potable water and gas transport applications.
As noted above, the study from Świetlik and Magnucka found that environmental, chemical, and biological factors can degrade the surface and structure of PE pipes. Such damage emerges as wrinkles on the inner surface of pipe with most damaged areas comprising “fragments of peeling antioxidant coatings and polyethylene itself.”
Most common contaminants from PE pipes included the following:
Leaching of these chemicals may help explain complaints about the taste and odor of water supplied through PE pipes. Taken together, these health and quality factors make it clear more study is needed to assess the safety of PE as a piping material.
As levels of MP and NP particles rise in the environment, their effects on health raises concerns among medical professionals. A growing body of research finds NP and MP particles across a wide range of animal organs, including the gut, lungs, brain, and reproductive systems. The impacts they are finding include possible degradation of organ function and associated impacts on overall health. The chemical and physical characteristics of MP and NP can also carry other substances and organisms that adhere to the particles, amplifying the reach and concentrations of harmful environmental and biological pollutants. The next sections of this report examine research looking at the effects of MP and NP on critical bodily systems.
Direct ingestion of MP and NP contamination in beverages including drinking water represents a primary source of human exposure. A study from the University of Minnesota found plastic particles in 81% of samples taken from a range of international metropolitan centers, and a review of over 400 data points across 26 studies estimated that those who drink only tap water ingest about 4,000 particles per year from this source. For those who drink only bottled water, the amount jumps to 90,000 particles per year. The same study estimates that an average American consumer ingests 39,000 to 52,000 MP and NP particles per year from food.
Much more research is needed, but lab studies have demonstrated significant effects of MP and NP particles on gut function, including:
How our bodies deal with MP and NP particles that pass into our digestive systems may depend on their size. The European Food Safety Authority concluded that the body excretes 90% of particles larger than 150 microns into fecal matter. By contrast, an earlier study showed roughly a third of 50 micron particles were absorbed by the gut, then moving throughout the body, including to the blood, marrow, liver, and spleen.
The studies reviewed above show the serious ways in which MP and NP particles impact the human body, from causing changes in the gut and lungs, to triggering further effects in the brain and reproductive systems that have potential to affect human health adversely. Many other research studies are looking at additional issues, including carcinogenic and genotoxic effects on humans and other animals, as well as harm to plants and other organisms. Researchers still do not fully understand how MP and NP affect the body, but the existing body of evidence suggests that following the precautionary principle is warranted with regard to plastics.
While treatment systems limit transmission of MP and NP from drinking-water sources, contamination that enters the system after that point remains largely unmonitored and unmitigated. The research showing that MP and NP shed from plastic plumbing materials poses a question: How can we reduce ingestion of these harmful particles? Adding a filter at point of use is one option. Replacing aging plastic pipe with alternative materials such as copper, cast-iron, or other proven materials is another option. An upcoming report will give a comprehensive view of the possibilities.
The company is the world’s best Pvc Particles supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.