Aug 30 2001
It is an amorphous commodity thermoplastic that can be colorless and transparent but is much more commonly pigmented. It is strong, stiff, and inherently flame retardant with relatively good chemical resistance (solvents are its weak area, particularly stress cracking therein).
It has good UV resistance and barrier properties but a limited operational temperature range, and unless modified it becomes brittle at 5 °C with an upper continuous use temperature of 50 °C. As additive-free PVC begins to decompose before it melts, it can only be melt processed by the use of copolymers or the addition of stabilizers (or by the addition of plasticizers which gives rise to products of different properties).
Polymer Type
Thermoplastic
Advantages
Cheap, good acid and alkali resistance. Flame-retardant. Stiff and strong. Can be transparent. Good vapour barrier properties. Good UV resistance.
Disadvantages
Difficult to melt process, requires modification. Limited solvent stress cracking resistance. Becomes brittle at (c 5 °C (40 °F) ) unless impact modified. Low continuous service temperature of 50 °C (120 °F).
Applications
Pipe and pipefittings, building products e.g. gutters, cladding, window frames. Bottles, film, LP records, floor tiling
While PVC is extensively used as cable insulation, this is generally made from plasticized grades (or sometimes from cross-linked PVC for minimum flammability).
Typical Properties
| Property |
Value |
| Density (g/cm3) |
1.4 |
| Surface Hardness |
RR110 |
| Tensile Strength (MPa) |
51 |
| Flexural Modulus (GPa) |
3 |
| Notched Izod (kJ/m) |
0.08 |
| Linear Expansion (/°C x 10-5) |
6 |
| Elongation at Break (%) |
60 |
| Strain at Yield (%) |
3.5 |
| Max. Operating Temp. (°C) |
50 |
| Water Absorption (%) |
0.1 |
| Oxygen Index (%) |
45 |
| Flammability UL94 |
V0 |
| Volume Resistivity (log ohm.cm) |
14 |
| Dielectric Strength (MV/m) |
14 |
| Dissipation Factor 1 kHz |
0.025 |
| Dielectric Constant 1 kHz |
3.1 |
| HDT @ 0.45 MPa (°C) |
70 |
| HDT @ 1.80 MPa (°C) |
67 |
| Material. Drying hrs @ (°C) |
2 @ 75 |
| Melting Temp. Range (°C) |
150 - 220 |
| Mould Shrinkage (%) |
0.4 |
| Mould Temp. Range (°C) |
20 - 40 |
Source : Abstracted from Plascams
For more information on Plascams please visit RAPRA Technology Ltd.