PE-HD: Polyethylene high density
- Short Name
- PE-HD
- Name
- Polyethylene high density
- Group
- CTP - Commodity Thermoplastics
- General Properties
- Chemical Formula
- Structural Formula
-
Properties
- Glass Transition Temperature
- -130 to -100 °C
- Melting Temperature
- 125 to 135 °C
- Melting Enthalpy
- 293 J/g
- Decomposition Temperature
- 480 to 498 °C
- Young's Modulus
- 600 to 1400 MPa
- Coefficient of Linear Thermal Expansion
- 200 to 250 *10¯6/K
- Specific Heat Capacity
- 1.8 to 2.7 J/(g*K)
- Thermal Conductivity
- 0.33 to 0.53 W/(m*K)
- Density
- 0.94 to 0.96 g/cm³
- Morphology
- Semi-crystalline thermoplastic
- General properties
- Better chemical reistance compared to PE-LD, good electrical insulating properties.
- Processing
- Extrusion (foils, profiles), Blow moulding, extrusion (foils, profiles), deep-drawing, injection moulding.
- Applications
- Films (for different applications), packaging for household and industry (e.g. bottles, plastic bags, beverage bottles caps), gas and water pipes, cable lines.
Internet Links
NETZSCH Measurements
- Instrument
- DSC 204 F1 Phoenix®
- Sample Mass
- 10.49 mg
- Isothermal Phase
- 20 min/2 min/20 min
- Heating/Colling Rates
- 10 K/min
- Crucible
- Al, pierced
- Atmosphere
- N2 (40 ml/min)
Evaluation
Although PE-HD belongs to the semi-crystalline thermoplastics, the measurement curves reflect only a melting effect with a peak temperature of approx. 133°C and a melting enthalpy of approx. 201 J/g (2nd heating, green). A glass transition range would have been expected between -130°C and -100°C; however, the specific heat hanges are probably too small to be detected in this case.
PE-LD and PE-HD differ significantly in their melting temperature. While the low density polyethylene (PE-LD) on page 69 has a peak temperature of 112°C in the 2nd heating (green), the above example for high-density polyethylene (PE-HD) has a peak temperature of 133°C. Linear low-density polyethylene (PE-LLD) shows a melting effect with characteristic double peak structure (see page 71), with a main peak temperature (approx. 124°C) that lies between the two previously mentioned values.
PE-LD and PE-HD differ significantly in their melting temperature. While the low density polyethylene (PE-LD) on page 69 has a peak temperature of 112°C in the 2nd heating (green), the above example for high-density polyethylene (PE-HD) has a peak temperature of 133°C. Linear low-density polyethylene (PE-LLD) shows a melting effect with characteristic double peak structure (see page 71), with a main peak temperature (approx. 124°C) that lies between the two previously mentioned values.