Terminology

• PVC: polyvinyl chloride
• Rigid / flexible (plasticized) PVC: unplasticized / with phthalate or other plasticizer
• Vinyl chloride monomer (VCM): the feedstock; a recognized carcinogen
• DEHP / BBzP: phthalate plasticizers
• Heat stabilizer: additive that prevents thermal degradation during processing and service
• Suspension polymerization: process producing about 80 percent of PVC

History and demand

Invention

• 1872: Eugen Baumann first synthesized PVC; early 20th-century processing attempts failed because the rigid polymer was hard to work
• 1926: Waldo Semon and B.F. Goodrich plasticized PVC; dibutyl phthalate in use by 1933

Sourcing

• 2024 production by one market overview: China 11 million tons, the United States 7.7 million, India 2.5 million, together 49 percent of world output; other editions put China at 12 to 16 million tons (IndexBox)
• About half of PVC capacity is in China

Demand trend

• Third most widely produced synthetic plastic, about 40 million tons per year
• Roughly half of world PVC resin goes to pipe; rigid PVC is used for window frames, sills, doors, and siding, and plasticized vinyl for flooring
• Recycling in Europe was 731,461 tonnes in 2020, down 5 percent from 2019

Composition and production

Raw materials

• Polymerized vinyl chloride, about 57 percent chlorine by mass
• Additives are almost always compounded in; flexible PVC can be over 85 percent plasticizer by mass

Properties

Physical

• Density: 1.4 g/cm³ (about 87 lb/ft³); rigid 1.3 to 1.45, flexible 1.1 to 1.35 g/cm³

Mechanical

• Yield strength: rigid 31 to 60 MPa (4.5 to 8.7 ksi); flexible 10.0 to 24.8 MPa (1.5 to 3.6 ksi)
• Modulus of elasticity (rigid): 3.4 GPa (about 490 ksi)

Thermal and moisture

• Coefficient of thermal expansion (rigid): 5 × 10⁻⁵ per °C, about 2.8 × 10⁻⁵ in./in./°F
• Glass transition: 82°C (180°F); heat distortion begins around 60°C (140°F) in traditional products; raw PVC degrades near 250°C (480°F)

Fire behavior

• Burning releases hydrogen chloride; chlorine content helps PVC-coated wire resist fire by scavenging free radicals

Standards

Material specifications

• ASTM D2665, F891, F1488: PVC drain, waste, and vent pipe
• ASTM D4434: PVC sheet roofing
• AAMA 303: rigid PVC profiles

Uses in buildings

Building elements

• Vinyl Windows, Fixed Windows, Casement Windows, Awning Windows, Double-Hung Windows, Horizontal Sliding Windows, Sliding and Folding Glass Wall Systems: extruded PVC frames and sashes
• PVC Roofing: flexible single-ply membrane
• Luxury Vinyl Flooring: luxury vinyl tile and plank
• Conduit and Raceways, Sanitary and Vent Piping, Floor Drains and Cleanouts: rigid PVC conduit, drain pipe, and drain bodies
• Wall Cladding: vinyl siding

Pros and cons

Pros

• Rigid grades 31 to 60 MPa yield strength
• Plasticizer content tunes flexibility from rigid to flexible
• Used for pipe, frames, siding, and flooring

Cons

• Releases hydrogen chloride when burned
• High thermal expansion (2.8 × 10⁻⁵ in./in./°F)
• Heat distortion begins near 140°F in traditional products
• Phthalates are not chemically bound and can leach out

Design considerations

Movement

• Expansion about 0.34 in. per 10 ft for a 100°F swing (calculated from 2.8 × 10⁻⁵ in./in./°F)

Sustainability

Health

• VCM caused liver angiosarcoma in polymerization workers in the early 1970s and is accepted as a carcinogen
• Phthalates leach; a 2004 Swedish-Danish study linked indoor DEHP and BBzP to childhood allergies
• Lead stabilizers leached into drinking water from pipes; their use has been discontinued in Europe
• Dioxin formation from waste burning: studies are mixed

Manufacturing and cost

Main manufacturers and suppliers

• Shintech
• OxyChem (Occidental)
• Westlake
• Charlotte Pipe

Trade association: Vinyl Institute.

Sources

• Wikipedia: Polyvinyl chloride, https://en.wikipedia.org/wiki/Polyvinyl_chloride
• UpCodes: 2024 IBC Chapter 15 roof assemblies, Chapter 15 Roof Assemblies and Rooftop Structures: Department of Defense Building Code 2024 | UpCodes
• Wikimedia Commons: Vinyl-siding.jpg, photo by Peter Rockwood (CC BY-SA 4.0), https://commons.wikimedia.org/wiki/File:Vinyl-siding.jpg
• IndexBox: polyvinyl chloride world market overview 2024, https://www.indexbox.io/blog/polyvinyl-chloride-world-market-overview-2024-11/