Electrical Properties of Polymers
Volume Resistivity of polymers material measures
how strongly a plastic material opposes the flow of electric current through a volume of cubic specimen. The lower the resistivity the higher the conductivity (electric charges meet a weak resistance to circulation).
It is also known as electrical resistivity, bulk resistivity, specific electrical resistance, specific volume resistance, or simply resistivity.
Volume Resistivity is measured in units: ohm-meter (Ohm-m or Ohm-cm).
- Below 105 Ohm-cm the material is considered as conductive.
- Above 109 Ohm-cm the material is considered as an electrical insulator.
Check out more on Volume Resistivity:
» Importance of Volume Resistivity
» How to Measure Volume Resistivity?
» Volume Resistivity Vs Surface Resistivity
» Factors Affecting Insulation Resistance
» Volume Resistivity Values of Several Plastics
Importance of Volume Resistivity
Volumes resistivity can be used as an aid in designing an insulator for a specific application. The change in resistivity with temperature and humidity may be great and must be known when designing for operating conditions.
Volumes resistivity determinations are often used in checking the uniformity of an insulating material, either with regards to:
- Processing, or
- Detect the conductive impurities that affect the quality of the material
Volume resistivities above 10
21 Ω-cm (10
19 Ω-m), calculated from data obtained on specimens tested under usual laboratory conditions, are of doubtful validity, considering the limitations of commonly used measuring equipment.
Applications include:
- Design of an insulator for a specific application
- Screening of conductive pastes
- Define applications for conducting composites
How to Measure Volume Resistivity?
The most usual test methods to determine plastics volume resistivity are
ASTM D257, ASTM D4496-04, ASTM D991-89(2005) or IEC 60093 (of course there exist several other methods as well!)
In the usual test, a standard size specimen is placed between two electrodes. For sixty seconds, a voltage is applied and the resistance is measured. Volumetric resistivity is, then, calculated and the apparent value for a 60 second electrification time is given. A 4-inch disk is preferable as the specimen size for the test.
Volume Resistivity Vs Surface Resistivity
The resistance offered by an insulating material to the electric current is the composite effect of volume and surface resistances, which always act in parallel.
- Volume resistance is the resistance to leakage if the electric current passes through the body of the material.
- It depends largely on the nature of the material
- On the other hand, surface resistance, which is the resistance to leakage along the surface of a material, is largely a function of surface finish and cleanliness
- Surface resistance is reduced by oil or moisture on the surface and by surface roughness
- And, very smooth or polished surface gives greater surface resistance
The insulation resistance of a dielectric is represented by its “Volume Resistivity” and “Surface Resistivity”.
The range of volume resistivities of different materials is shown below in ‘The Resistivity Spectrum’
Source: Plastics Technology Handbook, Fifth Edition
Values for plastics typically range from 10
10 ohm-cm for Cellulose Acetate to about 10
19 ohm-cm for a high-performance polystyrene.
Factors Affecting Insulation Resistance
The insulation resistance of most plastics is affected by temperature and the relative humidity of the atmosphere
The insulation resistance falls off appreciably with an increase in temperature or humidity
Even
PS , which has very high insulation resistance at room temperature, becomes generally unsatisfactory above 80°C (176°F). Under these conditions, polymers like
PTFE and PCTFE are more suitable.
Plastics that have high water resistance are relatively less affected by high humidities.
The longer the voltage is applied (longer electrification times) the higher the volume resistivity that is measured.
The presence of fillers in the polymer will affect the volume resistivity. The type and amount of filler change the volume resistivity.
Volume Resistivity Values of Several Plastics
Click to find polymer you are looking for:
A-C |
E-M |
PA-PC |
PE-PL |
PM-PP |
PS-X
| Polymer Name |
Min Value (1015 Ohm.cm) |
Max Value (1015 Ohm.cm) |
| ABS - Acrylonitrile Butadiene Styrene |
14.0 |
16.0 |
| ABS Flame Retardant |
14.0 |
15.0 |
| ABS High Heat |
16.0 |
16.0 |
| ABS High Impact |
16.0 |
16.0 |
| ABS/PC Blend - Acrylonitrile Butadiene Styrene/Polycarbonate Blend |
14.0 |
17.0 |
| ABS/PC Blend 20% Glass Fiber |
16.0 |
17.0 |
| ABS/PC Flame Retardant |
16.0 |
17.0 |
| ASA - Acrylonitrile Styrene Acrylate |
14.0 |
15.0 |
| ASA/PC Blend - Acrylonitrile Styrene Acrylate/Polycarbonate Blend |
13.05 |
15.0 |
| ASA/PC Flame Retardant |
14.0 |
14.0 |
| CA - Cellulose Acetate |
12.0 |
12.0 |
| CAB - Cellulose Acetate Butyrate |
13.0 |
13.0 |
| CP - Cellulose Proprionate |
11.0 |
11.0 |
| COC - Cyclic Olefin Copolymer |
14.0 |
15.0 |
| CPVC - Chlorinated Polyvinyl Chloride |
15.0 |
16.0 |
| ECTFE - Ethylene ChloroTriFluoroEthylene |
16.0 |
16.0 |
| ETFE - Ethylene Tetrafluoroethylene |
15.0 |
17.0 |
| EVA - Ethylene Vinyl Acetate |
15.0 |
15.0 |
| EVOH - Ethylene Vinyl Alcohol |
12.0 |
13.0 |
| FEP - Fluorinated Ethylene Propylene |
17.0 |
18.0 |
| HDPE - High Density Polyethylene |
16.0 |
18.0 |
| HIPS - High Impact Polystyrene |
16.0 |
16.0 |
| HIPS Flame Retardant V0 |
15.0 |
16.0 |
| Ionomer (Ethylene-Methyl Acrylate Copolymer) |
16.0 |
16.0 |
| LCP - Liquid Crystal Polymer |
16.0 |
16.0 |
| LCP Carbon Fiber-reinforced |
-1.0 |
-8.0 |
| LCP Glass Fiber-reinforced |
15.0 |
15.0 |
| LCP Mineral-filled |
12.0 |
16.0 |
| LDPE - Low Density Polyethylene |
0.917 |
0.940 |
| LLDPE - Linear Low Density Polyethylene |
16.0 |
18.0 |
| MABS - Transparent Acrylonitrile Butadiene Styrene |
13.0 |
14.0 |
| PA 46 - Polyamide 46 |
15.0 |
15.0 |
| PA 46, 30% Glass Fiber |
10.0 |
13.0 |
| PA 6 - Polyamide 6 |
14.0 |
14.0 |
| PA 6-10 - Polyamide 6-10 |
14.0 |
14.0 |
| PA 66 - Polyamide 6-6 |
14.0 |
14.0 |
| PA 66, 30% Glass Fiber |
13.0 |
13.0 |
| PA 66, 30% Mineral filled |
12.0 |
15.0 |
| PA 66, Impact Modified, 15-30% Glass Fiber |
12.0 |
13.0 |
| PA 66, Impact Modified |
11.0 |
15.0 |
| PAI - Polyamide-Imide |
12.0 |
17.0 |
| PAI, 30% Glass Fiber |
14.0 |
17.0 |
| PAR - Polyarylate |
16.0 |
17.0 |
| PARA (Polyarylamide), 30-60% glass fiber |
15.0 |
15.0 |
| PBT - Polybutylene Terephthalate |
14.0 |
17.0 |
| PBT, 30% Glass Fiber |
16.0 |
16.0 |
| PC (Polycarbonate) 20-40% Glass Fiber |
15.0 |
16.0 |
| PC (Polycarbonate) 20-40% Glass Fiber Flame Retardant |
15.0 |
17.0 |
| PC - Polycarbonate, high heat |
15.0 |
16.0 |
| PC/PBT Blend - Polycarbonate/Polybutylene Terephthalate Blend |
16.0 |
17.0 |
| PC/PBT blend, Glass Filled |
15.0 |
16.0 |
| PCTFE - Polymonochlorotrifluoroethylene |
14.0 |
15.0 |
| PE - Polyethylene 30% Glass Fiber |
16.0 |
16.0 |
| PEEK - Polyetheretherketone |
16.0 |
17.0 |
| PEEK 30% Carbon Fiber-reinforced |
1.0 |
8.0 |
| PEEK 30% Glass Fiber-reinforced |
15.0 |
16.0 |
| PEI - Polyetherimide |
5.0 |
18.0 |
| PEI, 30% Glass Fiber-reinforced |
15.0 |
16.0 |
| PEKK (Polyetherketoneketone), Low Crystallinity Grade |
1.0 |
1.0 |
| PESU - Polyethersulfone |
15.0 |
17.0 |
| PESU 10-30% glass fiber |
15.0 |
16.0 |
| PET - Polyethylene Terephthalate |
16.0 |
16.0 |
| PET, 30% Glass Fiber-reinforced |
15.0 |
16.0 |
| PET, 30/35% Glass Fiber-reinforced, Impact Modified |
0.0 |
2.0 |
| PFA - Perfluoroalkoxy |
16.0 |
18.0 |
| PGA - Polyglycolides |
1.400 |
1.600 |
| PI - Polyimide |
14.0 |
18.0 |
| PMMA - Polymethylmethacrylate/Acrylic |
14.0 |
16.0 |
| PMMA (Acrylic) High Heat |
15.0 |
15.0 |
| PMMA (Acrylic) Impact Modified |
14.0 |
16.0 |
| PMP - Polymethylpentene |
16.0 |
18.0 |
| PMP 30% Glass Fiber-reinforced |
16.0 |
17.0 |
| PMP Mineral Filled |
16.0 |
16.0 |
| POM - Polyoxymethylene (Acetal) |
14.0 |
15.0 |
| POM (Acetal) Impact Modified |
15.0 |
16.0 |
| POM (Acetal) Low Friction |
15.0 |
16.0 |
| PP - Polypropylene 10-20% Glass Fiber |
16.0 |
17.0 |
| PP, 10-40% Mineral Filled |
16.0 |
17.0 |
| PP, 10-40% Talc Filled |
16.0 |
17.0 |
| PP, 30-40% Glass Fiber-reinforced |
16.0 |
17.0 |
| PP (Polypropylene) Copolymer |
16.0 |
18.0 |
| PP (Polypropylene) Homopolymer |
16.0 |
18.0 |
| PP, Impact Modified |
16.0 |
18.0 |
| PPA - Polyphthalamide |
15.0 |
15.0 |
| PPA, 30% Mineral-filled |
14.0 |
16.0 |
| PPA, 33% Glass Fiber-reinforced – High Flow |
14.0 |
16.0 |
| PPA, 45% Glass Fiber-reinforced |
14.0 |
16.0 |
| PPE - Polyphenylene Ether |
15.0 |
16.0 |
| PPE, 30% Glass Fiber-reinforced |
15.0 |
16.0 |
| PPE, Flame Retardant |
15.0 |
16.0 |
| PPS - Polyphenylene Sulfide |
15.0 |
16.0 |
| PPS, 20-30% Glass Fiber-reinforced |
16.0 |
16.0 |
| PPS, 40% Glass Fiber-reinforced
|
16.0 |
16.0 |
| PPS, Conductive
|
1.0 |
3.0 |
| PPS, Glass fiber & Mineral-filled |
15.0 |
16.0 |
| PPSU - Polyphenylene Sulfone
|
14.0 |
16.0 |
| PS (Polystyrene) 30% glass fiber
|
16.0 |
16.0 |
| PS (Polystyrene) Crystal |
16.0 |
17.0 |
| PS, High Heat |
16.0 |
16.0 |
| PSU - Polysulfone
|
15.0 |
17.0 |
| PSU, 30% Glass finer-reinforced
|
15.0 |
16.0 |
| PSU Mineral Filled
|
16.0 |
16.0 |
| PTFE - Polytetrafluoroethylene
|
17.0 |
18.0 |
| PTFE, 25% Glass Fiber-reinforced
|
16.0 |
18.0 |
| PVC (Polyvinyl Chloride), 20% Glass Fiber-reinforced
|
15.0 |
16.0 |
| PVC, Plasticized |
10.0 |
16.0 |
| PVC, Plasticized Filled
|
10.0 |
16.0 |
| PVC Rigid
|
15.0 |
16.0 |
| PVDC - Polyvinylidene Chloride
|
15.0 |
16.0 |
| PVDF - Polyvinylidene Fluoride
|
5.0 |
14.0 |
| SAN - Styrene Acrylonitrile |
16.0 |
16.0 |
| SAN, 20% Glass Fiber-reinforced
|
15.0 |
17.0 |
| SMA - Styrene Maleic Anhydride
|
16.0 |
16.0 |
| SMA, 20% Glass Fiber-reinforced
|
15.0 |
15.0 |
| SMMA - Styrene Methyl Methacrylate
|
15.0 |
15.0 |
| UHMWPE - Ultra High Molecular Weight Polyethylene |
16.0 |
17.0 |