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嘉峪检测网 2019-02-20 09:08
介质在外加电场时会产生感应电荷而削弱电场,介质中的电场减小与原外加电场(真空中)的比值即为相对介电常数(relative permittivity或dielectric constant),又称诱电率,与频率相关。介电常数是相对介电常数与真空中绝对介电常数乘积。如果有高介电常数的材料放在电场中,电场的强度会在电介质内有可观的下降。理想导体(金属)的相对介电常数为无穷大。
根据物质的介电常数可以判别高分子材料的极性大小。通常,相对介电常数大于3.6的物质为极性物质;相对介电常数在2.8~3.6范围内的物质为弱极性物质;相对介电常数小于2.8为非极性物质。
同理,我们根据高分子材料的极性也可以大致推测材料介电常数大小,极性基团多,介电常数高,极性基团少介电常数小。下面是常见材料的介电常数的大小:
聚合物 |
最低值 |
最高值 |
HIPS Flame Retardant V0 |
2 |
3 |
PCTFE - Polymonochlorotrifluoroethylene |
2 |
3 |
PMMA - Polymethylmethacrylate/Acrylic |
2 |
5 |
FEP - Fluorinated Ethylene Propylene |
2.1 |
2.1 |
PFA - Perfluoroalkoxy |
2.1 |
2.1 |
PTFE - Polytetrafluoroethylene |
2.1 |
2.1 |
PMP - Polymethylpentene |
2.1 |
3.6 |
HDPE - High Density Polyethylene |
2.3 |
2.3 |
LDPE - Low Density Polyethylene |
2.3 |
2.3 |
LLDPE - Linear Low Density Polyethylene |
2.3 |
2.3 |
PMP Mineral Filled |
2.3 |
2.3 |
PP, 10-40% Mineral Filled |
2.3 |
2.3 |
PP, 10-40% Talc Filled |
2.3 |
2.3 |
PP (Polypropylene) Copolymer |
2.3 |
2.3 |
PP (Polypropylene) Homopolymer |
2.3 |
2.3 |
PP, Impact Modified |
2.3 |
2.3 |
UHMWPE - Ultra High Molecular Weight Polyethylene |
2.3 |
2.3 |
PMP 30% Glass Fiber-reinforced |
2.4 |
2.4 |
PS (Polystyrene) Crystal |
2.4 |
2.7 |
PS, High Heat |
2.4 |
2.7 |
HIPS - High Impact Polystyrene |
2.4 |
4.8 |
ABS High Heat |
2.4 |
5 |
ABS High Impact |
2.4 |
5 |
PS (Polystyrene) 30% glass fiber |
2.5 |
2.5 |
EVA - Ethylene Vinyl Acetate |
2.5 |
3 |
SAN - Styrene Acrylonitrile |
2.5 |
3.4 |
ECTFE |
2.57 |
2.59 |
ETFE - Ethylene Tetrafluoroethylene |
2.6 |
2.6 |
PP - Polypropylene 10-20% Glass Fiber |
2.6 |
2.6 |
PP, 30-40% Glass Fiber-reinforced |
2.6 |
2.6 |
PPE - Polyphenylene Ether |
2.7 |
2.7 |
PPE, Flame Retardant |
2.7 |
2.7 |
PE - Polyethylene 30% Glass Fiber |
2.7 |
2.8 |
ABS - Acrylonitrile Butadiene Styrene |
2.7 |
3.2 |
SMA - Styrene Maleic Anhydride |
2.8 |
2.8 |
ABS Flame Retardant |
2.8 |
3 |
MABS - Transparent Acrylonitrile Butadiene Styrene |
2.8 |
3 |
PC - Polycarbonate, high heat |
2.8 |
3.8 |
PPE, 30% Glass Fiber-reinforced |
2.9 |
2.9 |
ABS/PC Blend - Acrylonitrile Butadiene Styrene/Polycarbonate Blend |
2.9 |
3.2 |
PMMA (Acrylic) Impact Modified |
2.9 |
3.7 |
PBT - Polybutylene Terephthalate |
2.9 |
4 |
PA 66, Impact Modified |
2.9 |
5 |
PC/PBT Blend - Polycarbonate/Polybutylene Terephthalate Blend |
2.95 |
3.14 |
PTFE, 25% Glass Fiber-reinforced |
3 |
3 |
PSU - Polysulfone |
3 |
3.2 |
PPS - Polyphenylene Sulfide |
3 |
3.3 |
ASA/PC Blend - Acrylonitrile Styrene Acrylate/Polycarbonate Blend |
3 |
3.4 |
PC (Polycarbonate) 20-40% Glass Fiber |
3 |
3.5 |
PC (Polycarbonate) 20-40% Glass Fiber Flame Retardant |
3 |
3.8 |
CP - Cellulose Proprionate |
3 |
4 |
LCP Glass Fiber-reinforced |
3 |
4 |
PA 6-10 - Polyamide 6-10 |
3 |
4 |
PBT, 30% Glass Fiber |
3 |
4 |
PEI, 30% Glass Fiber-reinforced |
3 |
4 |
PEI, Mineral Filled |
3 |
4 |
PET - Polyethylene Terephtalate |
3 |
4 |
PET, 30% Glass Fiber-reinforced |
3 |
4 |
PETG - Polyethylene Terephtalate Glycol |
3 |
4 |
POM (Acetal) Low Friction |
3 |
4 |
PVC Rigid |
3 |
4 |
PVC, Plasticized |
3 |
5 |
PVC, Plasticized Filled |
3 |
5 |
LCP Mineral-filled |
3 |
5.9 |
CPVC - Chlorinated Polyvinyl Chloride |
3 |
6 |
PVDC - Polyvinylidene Chloride |
3 |
6 |
CAB - Cellulose Acetate Butyrate |
3 |
7 |
CA - Cellulose Acetate |
3 |
8 |
PA 11, Conductive |
3 |
9 |
PA 11, Flexible |
3 |
9 |
PA 11, Rigid |
3 |
9 |
PA 12 (Polyamide 12), Conductive |
3 |
9 |
PA 12, Fiber-reinforced |
3 |
9 |
PA 12, Flexible |
3 |
9 |
PA 12, Glass Filled |
3 |
9 |
PA 12, Rigid |
3 |
9 |
SRP - Self-reinforced Polyphenylene |
3.1 |
3.1 |
ABS/PC Blend 20% Glass Fiber |
3.1 |
3.2 |
PEI - Polyetherimide |
3.1 |
3.2 |
PI - Polyimide |
3.1 |
3.55 |
ASA/PC Flame Retardant |
3.2 |
3.2 |
PEEK - Polyetheretherketone |
3.2 |
3.2 |
SMMA - Styrene Methyl Methacrylate |
3.2 |
3.2 |
PEEK 30% Carbon Fiber-reinforced |
3.2 |
3.4 |
SAN, 20% Glass Fiber-reinforced |
3.2 |
3.8 |
PMMA (Acrylic) High Heat |
3.2 |
4 |
LCP - Liquid Crystal Polymer |
3.3 |
3.3 |
PAR - Polyarylate |
3.3 |
3.3 |
PEKK (Polyetherketoneketone), Low Cristallinity Grade |
3.3 |
3.3 |
SMA, 20% Glass Fiber-reinforced |
3.3 |
3.3 |
ASA - Acrylonitrile Styrene Acrylate |
3.3 |
3.8 |
PPS, 20-30% Glass Fiber-reinforced |
3.3 |
3.8 |
PC/PBT blend, Glass Filled |
3.3 |
3.9 |
PEEK 30% Glass Fiber-reinforced |
3.3 |
4.2 |
POM - Polyoxymethylene (Acetal) |
3.3 |
4.7 |
PPSU - Polyphenylene Sulfone |
3.4 |
3.5 |
PA 46 - Polyamide 46 |
3.4 |
3.8 |
PA 66, Impact Modified, 15-30% Glass Fiber |
3.4 |
4.2 |
Amorphous TPI Blend, Ultra-high heat, Chemical Resistant (Standard Flow) |
3.5 |
3.5 |
PESU - Polyethersulfone |
3.5 |
4.1 |
PA 66, 30% Glass Fiber |
3.5 |
5.6 |
PSU, 30% Glass finer-reinforced |
3.6 |
3.7 |
PPA, 33% Glass Fiber-reinforced – High Flow |
3.7 |
3.9 |
PARA (Polyarylamide), 30-60% glass fiber |
3.9 |
4.5 |
PAI - Polyamide-Imide |
3.9 |
7.3 |
PPS, 40% Glass Fiber-reinforced |
4 |
4 |
PPA, 30% Mineral-filled |
4 |
4.2 |
POM (Acetal) Impact Modified |
4 |
4.3 |
PA 46, 30% Glass Fiber |
4 |
4.6 |
PA 6 - Polyamide 6 |
4 |
5 |
PA 66 - Polyamide 6-6 |
4 |
5 |
PA 66, 30% Mineral filled |
4 |
5 |
PESU 10-30% glass fiber |
4.2 |
4.3 |
PAI, 30% Glass Fiber |
4.2 |
6.5 |
PPA - Polyphthalamide |
4.3 |
4.3 |
PPA, 33% Glass Fiber-reinforced |
4.4 |
4.6 |
PPA, 45% Glass Fiber-reinforced |
4.4 |
4.6 |
PA 11 - (Polyamide 11) 30% Glass fiber reinforced |
4.8 |
4.8 |
EVOH - Ethylene Vinyl Alcohol |
4.8 |
5.6 |
PPS, Glass fiber & Mineral-filled |
5 |
5 |
PVDF - Polyvinylidene Fluoride |
6 |
9 |
来源:AnyTesting