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Properties Chart: The Polyolefins

Property Units ASTM test method Polyethylene
 Polypropylene
Low density Medium Density High Density Homopolymer Copolymer
Density g/cm3 D792 0.910-0.925 0.926-0.941 0.942-0.970 0.890-0.915 0.890-0.905
Specific Volume cm3/g D792 1.09-1.07 1.07-1.06 1.06-1.04 1.13 1.13-1.10
Inj. Moulding temp. °C   150-290 150-290 180-351 200-300 200-300
Inj. Moulding press. MPa   55-100 70-140 70-140 70-140 70-140
Moulding qualities     Excellent Excellent Excellent Excellent Excellent
Extrusion temp. °C   120-315 135-315 150-315 170-300 170-300
Buring rate   D635 Very slow Very slow Very slow Slow Slow
Specific heat kJ6kg.K   2.3 2.3 2.3 1.92-2.3 2.09
Thermal conductivity W/m.K C177 0.46-0.52   0.33 0.08-0.017 0.005-0.010
Thermal expansion cm/cm.K D696 16-18x10-5   11-13x10-5 5-11x10-5 8.0-9.5x10-5
Heat distortion temp. °C(0.45 MPa) D648 40.6-49.4 48.9-65.6 60-88 98.9-121 85-113
Vicat softening point °C   85-87 95-105 120-130 150  
Tensile strength MPa D638 7-16 8-24 21-41 21-41 20.0-31.0
Ultimate elongation % D638 90-650 50-700 15-1000 40-600 200-700
Compressive strength MPa D695 11-16.5 18-21 16.5-22 59-69 25-55
Flexural strength MPa D790 No fracture 33-48 14-21   34.5-48
Flexural modulus MPa   310-380 520 760 120-1500 800-1400
Impact strength Izod J/m of notch D256 No break 27-295 80-640 30-120 60-1070
Modulus of elasticity in tension MPa D747 115-250 170-380 550-1050 900-1400 700-1200
Hardness   D2240 or D785 D40-D46 (Shore) D50-D70 (Shore) D60-D70 (Shore) R85-R110 R50-R96
Refractive Index nD   D542 1.51   1.54 1.49  
Volume resistivity ohm.cm D257 >1016 >1016 >1015->1018 >1016 >1017
Dissipation (power) factor at 1KHz   D150 <0.0005 <0.0005 <0.0002 0.0002-0.0008 0.0001-0.0008
Dissipation constant at 1KHz   D150 2.25-2.35 2.25-2.35 2.25-2.35 2.0-2.1 2.24-2.30
Dielectric strength kV/cm D149 175-400 175-400 175-200 200-260 200-260
Arc resistence s D495 135-160 200-235   186 136
Water absorption % D570 <0.015 <0.01 <0.01 <0.01 0.01-0.03
Odour     None None None None None
Machining qualities     Fair Good Excellent Excellent Excellent
Clarity     Translucent to opaque Translucent to opaque Translucent to opaque Translucent to opaque Translucent to opaque
Effect of sunlight     Surface crazing Surface crazing Surface crazing Affected Requires protection
Effoct of organic solvents   D543 Resistant below 60°C Resistant below 60°C Resistant below 80°C Resistant below 80°C Resistant below 80°C
Chemical resistance   D543 Attacked slowly by oxidising acids Attacked slowly by oxidising acids Attacked slowly by oxidising acids Attacked slowly by oxidising acids Attacked slowly by oxidising acids