A. Polyvinyl chloride (PVC):
Polyvinyl chloride, more correctly but unusually poly(vinyl chloride), commonly abbreviated PVC, is the third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene.
PVC comes in two basic forms: rigid(sometimes abbreviated as RPVC) and flexible. The rigid form of PVC is used in construction for pipe and in profile applications such as doors and windows. It is also used for bottles, other non-food packaging, and cards (such as bank or membership cards). It can be made softer and more flexible by the addition of plasticizers, the most widely used being phthalates. In this form, it is also used in plumbing, electrical cable insulation, imitation leather, signage, inflatable products, and many applications where it replaces rubber.
Pure poly(vinyl chloride) is a white, brittle solid. It is insoluble in alcohol but slightly soluble in tetrahydrofuran.
B. Polyvinyl chloride (PVC) Features
Mechanical properties:
PVC has high hardness and mechanical properties. The mechanical properties enhance with the molecular weight increasing but decrease with the temperature increasing. The mechanical properties of rigid PVC (uPVC) are very
good; the elastic modulus can reach 1500-3,000 MPa. The soft PVC (flexible PVC) elastic is 1.5-15 MPa. However, elongation at break is up to 200-450%. PVC friction is ordinary; the static friction factor is 0.4-0.5, and the dynamic friction factor is 0.23.
Thermal and fire properties:
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. PVC starts to decompose when the temperature reaches 140 °C, with melting temperature starting around 160 °C. The linear expansion coefficient of rigid PVCis small and has good flame retardancy, the Limiting oxygen index (LOI) being up to 45 or more. The LOI is the minimum concentration of oxygen, expressed as a percentage, that will support combustion of a polymer and noting that air has 20% content of oxygen.
Electrical properties
PVC is a polymer with good insulation properties, but because of its higher polar nature the electrical insulating property is inferior to non polar polymers such as polyethylene and polypropylene.Since the dielectric constant, dielectric loss tangent value, and volume resistivity are high, the corona
resistance is not very good, and it is generally suitable for medium or low voltage and low frequency insulation materials.
C. Polyvinyl chloride (PVC) Applications
1. Advertising: screen printing, engraving, advertising signs, exhibition board, sign board.
2. The furniture: bathroom furniture, all kinds of high-grade furniture with boards.
3. The architectural decoration industry: building cladding, decorative plates, residential buildings, offices, public cubicle, commercial decorative frame, clean room with board, ceiling board.
4. Transportation: ship, plane, bus, railway car, ceiling, box core layer, inner decoration with boards.
5. Industrial applications: chemical anti-corrosion engineering, thermoformed piece, cold storage with plate, special cold insulation engineering, environmental protection with plate
