IUPAC-Name (International Union of Pure and Applied Chemistry):
Polychloroethene
Synonyms:
vinyl, vinyl chloride homopolymer, chloroethylene polymer
German:
Polyvinylchlorid
Spanish:
policloruro de vinilo
French:
chlorure de polyvinyle
Italian:
cloruro di polivinile
Russian:
Поливинилхлорид
Arabic:
البولي فينيل كلوريد
Chinese:
聚氯乙烯
Japanese:
ポリ塩化ビニル
Chemical Formula:
H2C=CHCl
CAS-Nr.:
9002-86-2
ESIS entry:
-- (no EINECS or ELINCS registration)
PVC is an amorphous, long-chain plastic manufactured through polymerization of the vinyl chloride monomer (VCM). This material has been produced commercially for more than 50 years and is one of the chemical industry's primary products. PVC accounts for roughly one-fifth of all plastic production: more than 34 million tons were sold in 2007.
PVC's structure differs from polyethylene's only through the addition of the element, chlorine. It is composed of the petroleum derivative ethylene (43%) and chlorine (57%). Accordingly, this plastic is less dependent upon petroleum/natural gas than other thermoplastics, therefore making it more cost-effective. Chlorine also makes PVC fire-resistant, very resistant to chemicals, and easily mixable with many additives.
There are different PVC grades:
- Rigid PVC-U = unplasticized: Used, for example, in packaging, pipes, and window profiles.
- Flexible PVC-P = plasticized: Contains up to 40% plasticizer and is used for products such as blood bags, cable insulation, flooring, and synthetic leather.
- Paste PVC (Dispersion Resin, Emulsion PVC, Extender PVC): Used for applications like bottle caps, flooring, and dolls.
Market Study - Polyvinyl Chloride from Ceresana Research offers information on manufacturing and processing methods, as well as consumption shares for each variety.
Important characteristics of PVC: 
|
Parameter: |
PVC-U (rigid): |
PVC-P (soft): |
|
Density (g/cm³) |
1.38-1.55 |
1.16-1.35 |
|
Melting point (°C) |
80 (long exposure > 70°C is not recommended) |
|
|
Service temperature (°C) |
-15 to 70 |
|
|
Tensile strength (N/mm²) |
50-75 |
10-25 |
|
Tensile strength at break (N/mm²) |
10-50 |
170-400 |
|
Chemical resistance |
Very resistant to concentrated and diluted acids, alkalis, alcohols, oils, aliphatic hydrocarbons; Resistant to plant oils and oxidizers; Limited resistance to aldehydes; Decomposition through concentrated hydrochloric acid, ester, aromatic and halogenated hydrocarbons, ketones |
|
During production, PVC accumulates as a white and odorless powder. It is mechanically tough and durable, resistant to abrasion, corrosion, weathering, and water. PVC does not suffer from bacterial or termite attacks. However, it is sensitive to heat and light: heat and UV rays result in a loss of chlorine in the form of hydrochloric acid (HCl). This can be reduced through the addition of stabilizers. Hardness and durability can be modified through the addition of low molecular weight compounds in the polymer matrix. Incorporation of these so-called plasticizers in different amounts results in products with a wide range of characteristics. Another advantage of PVC is its ability to be colored. PVC is not only ideal for use as cable insulation because of its high rigidity; it also does not conduct electricity.
An overview of PVC's most important characteristics and detailed information on additives used in this plastic can be found in Market Study - Polyvinyl Chloride, from Ceresana Research.
No mandatory danger symbols (R/S statements) are required to label PVC. Fierce attacks from environmentalists have led to many investigations into possible health and environmental effects of PVC. This plastic has a positive life-cycle assessment, as a result of its relatively low energy consumption during manufacture (processing temperatures of only 170 to 200°C), its excellent insulation properties, and its comparatively low weight, which reduces resource consumption.
Controversial discussions have been, and will continue to be held worldwide, primarily regarding the production of raw materials through chlorine chemistry, health hazards concerning use and disposal of PVC, the reduction of cadmium and lead stabilizers, bans of phthalate plasticizers, as well as workplace requirements where chlorine is manufactured and where compounds are processed.
Additional information on PVC environmental discussions, legal issues, and recycling can be found in Market Study - Polyvinyl Chloride from Ceresana Research.
Manufacturing methods for PVC:
There are four production steps taken to transform raw materials into PVC end products: The vinyl chloride monomer (VCM) is manufactured from gas and salt. Following polymerization of the VCM into PVC, the base polymer is mixed with additives and then processed into end products, for example with extrusion.
In China, PVC is manufactured on the basis of acetylene, that is to say, coal is used as a starting material instead of oil. In contrast, petroleum and salt, specifically ethylene and chlorine, are used as starting substances throughout developed industrialized nations. Crude oil is cracked to ethylene - via the intermediate product naphtha. Chlorine is made from salt by chlor-alkali-electrolysis, usually with the membrane process. Caustic soda and hydrogen are important by-products here. They are in turn used as raw materials for other syntheses, for example, in the aluminum, glass, and paper industries. In the next step, one manufactures ethylene dichloride (EDC) at a temperature of 80°C, using iron compounds as catalysts. Afterward, splitting hydrogen chloride at 500°C transforms it into vinyl chloride.
Conversion of vinyl chloride into PVC can take place with the use of various methods, which allow different types of PVC to be produced with certain characteristics for specific applications: Suspension polymerization (S-PVC) play by far the largest role, accounting for roughly 80% of all manufactured PVC. Approximately 10% of PVC is produced with emulsion polymerization (E-PVC), while mass polymerization (M-PVC) plays a less important role. PVC paste can also be manufactured with micro-suspension polymerization (micro-S-PVC).
More information on PVC production and processing is provided by Market Study - Polyvinyl Chloride from Ceresana Research.
PVC is able to absorb a much greater variety of additives than all other plastics, and accordingly has the widest range of applications. The largest share of worldwide produced PVC is used in the construction industry, for example as flooring, window and door profiles, sun-screen applications, and façades, but most of all PVC is applied to pipes. With regard to pressure pipes, PVC is principally used for drinking water and wastewater supplies. For decades, unplasticized PVC has been the most commonly utilized plastic in cable insulation. Among other things, rigid PVC films are used as green house roofs, while flexible films are applied as sealing sheeting for housing construction, as well as geomembranes used in agriculture and landscaping. Calenderized PVC has been established in the packaging industry as a material for producing clamshell and blister packaging, which is used for example, in containers for medications. PVC and PVC composite coatings are primarily applied in the construction industry as insulation and sealing compounds, but are also used in the automotive industry as undercoating, due to their anti-corrosive properties. Additional application areas for this plastic include shoe soles and bottles, although demand for these products has been falling for quite some time throughout the developed, industrialized nations. Further examples are synthetic leather, toys, medical products like gloves and transfusion bags, as well as sporting and leisure goods.
Market Study - Polyvinyl Chloride from Ceresana Research offers comprehensive information on consumption amounts within individual application areas and divides them among the different world regions.
(->for more info see Market Study - Polyvinyl Chloride from Ceresana Research)
Last Revision: 19.01.09
