May 26 2003
Background
Polyvinylidenechloride ( PVDC ) is a transparent and almost colourless thermoplastic noted for its extremely low permeability to gases. As the homopolymer begins to decompose at or marginally above its melting point (200°C), all commercially available grades are copolymers (with vinyl chloride, acrylates or nitriles) and stabilisers are also normally necessary.
Applications
The applications of Polyvinylidenechloride ( PVDC ),are predominantly packaging and barrier films, often as the barrier layer in multi-layer structures.
Key Properties
The key properties of Polyvinylidenechloride ( PVDC ) are tabulated below.
Table 1. Key properties
| Chemical Resistance |
| Acids - concentrated |
Good |
| Acids - dilute |
Good |
| Alcohols |
Good |
| Alkalis |
Good |
| Aromatic hydrocarbons |
Fair |
| Greases and Oils |
Good |
| Halogens |
Good |
| Ketones |
Fair |
| Electrical Properties |
| Dielectric constant @ 1 MHz |
3.0 - 6.0 |
| Surface resistivity ( Ohm/sq ) |
1012 - 1013 |
| Volume resistivity ( Ohm.cm ) |
1012 - 1016 |
| Mechanical Properties |
| Coefficient of friction |
0.24 |
| Hardness - Rockwell |
R98 - 106 |
| Izod impact strength ( J m-1 ) |
16 - 53 |
| Tensile modulus ( GPa ) |
0.3 - 0.55 |
| Tensile strength ( MPa ) |
25 - 110 |
| Physical Properties |
| Density ( g.cm-3 ) |
1.63 |
| Flammability |
Self Extinguishing |
| Limiting oxygen index ( % ) |
60 |
| Resistance to Ultra-violet |
Fair |
| Water absorption - over 24 hours ( % ) |
0.1 |
| Thermal Properties |
| Coefficient of thermal expansion ( x10-6 K-1 ) |
190 |
| Thermal conductivity ( W.m-1.K-1 ) |
0.13 @ 23 |
| Upper working temperature (°C ) |
80 - 100 |
| Properties Polyvinylidenechloride Film |
| Property |
|
Value |
| Dielectric Strength @ 25 µm thick |
KV.mm-1 |
160 - 280 |
| Dissipation Factor @ 1 MHz |
|
0.05 - 0.08 |
| Elongation at Break |
% |
30 - 80 |
| Heat-sealing Temperature |
°C |
120 - 150 |
| Permeability to Carbon Dioxide @ 25 °C |
x10-13 cm3.cm.cm-2.s-1.Pa-1 |
0.02 |
| Permeability to Nitrogen @ 25 °C |
x10-13 cm3.cm.cm-2.s-1.Pa-1 |
0.0007 |
| Permeability to Oxygen @ 25 °C |
x10-13 cm3.cm.cm-2.s-1.Pa-1 |
0.004 |
| Permeability to Water @ 25 °C |
x10-13 cm3.cm.cm-2.s-1.Pa-1 |
7 |
About Goodfellow
Goodfellow supplies metals, ceramics and other materials to meet the research, development and specialist production requirements of science and industry worldwide.
The Goodfellow group consists of four companies. The main administration, research laboratories and workshops are located at the Company's headquarters in Cambridge, England. The subsidiary offices in America, France and Germany provide an additional service.