PVC
One polymer used in rigid drainpipes and flexible cable coverings.
- Also known as
- polyvinyl chloride, poly(chloroethene), vinyl, uPVC
In everyday products
- Drainpipe — Pipe wall
- Electrical cable covering — PVC insulation or sheath
- Window frame — uPVC frame profiles
- Vinyl flooring — PVC-based flooring layer
- Garden hose — Flexible PVC hose layers
- Vinyl pencil eraser — Soft PVC-based eraser block
Structure and behaviour
[–CH₂–CHCl–]ₙ
The monomer C=C bond becomes part of a saturated backbone; chlorine stays attached to alternate backbone carbons. Plasticisers change how the chains move but are not repeat units covalently inserted into this chain.
- Rigid PVC compounds hold the cross-section of pipe and window profiles after extrusion.
- A plasticiser increases chain mobility, allowing flexible cable coverings, hoses and flooring from the same polymer family.
- Heat stabilisers help the compound tolerate processing; chlorine in the repeat unit does not remove the need for formulation control.
- Continuous extrusion suits long pipes and covers; fillers, reinforcements and surface layers add functions beyond the PVC resin.
- Comparing rigid and flexible PVC shows how formulation can change a product even when the monomer and backbone remain the same.
Preparation routes
Vinyl chloride route
Free-radical addition polymerisation. Vinyl chloride molecules link into PVC chains. The resin is then formulated differently for rigid pipes and flexible coverings. The original double bond is consumed, while the C–Cl bonds remain in the repeat unit. Flexible and rigid PVC can therefore have the same polymer origin.
An initiator starts chain growth. Stabilising additives and, for flexible formulations, plasticisers are separate from the monomer. Plasticiser acts mainly by altering chain mobility; it is not a second polymerising feedstock.
- PVC: monomer production, polymerisation and usesChemical Industry Education Centre, University of York
From ethene to vinyl chloride
- Ethene + Chlorine → 1,2-Dichloroethane
Direct chlorination adds chlorine across ethene's double bond.
- 1,2-Dichloroethane → Chloroethene
Industrial cracking removes hydrogen chloride, leaving the double bond in vinyl chloride.
- PVC: monomer production, polymerisation and usesChemical Industry Education Centre, University of York
Material limits
Pipe ratings, electrical protection and fire performance belong to a finished formulation and design. Rigid and flexible PVC should not be treated as interchangeable recycling feedstocks. Sorting and separation are needed for metal, textile layers and additives; older durable products can contain legacy additives that complicate reuse.
Sources
- PVC: monomer production, polymerisation and usesChemical Industry Education Centre, University of York
- PVC recycling: sorting, separation and additivesVinylPlus