PE film, full name of Polyethylene, the most simple structure of the polymer compounds, the world's most widely used polymer materials, the ethylene polymerization, according to the density were divided into high density polyethylene, medium density polyethylene and low density polyethylene.
Low-density polyethylene is relatively soft, multi-purpose high-pressure polymerization; high-density polyethylene has a rigid, hardness and mechanical strength properties, the use of low-pressure polymerization. High-density polyethylene containers can be done, pipes, can do high-frequency electrical insulation materials, for radar and television. Often large-scale use of low-density (high pressure) polyethylene. Polyethylene wax, wax, like the smooth feeling, no staining, low-density polyethylene transparent, opaque high density polyethylene.
Polyethylene by ethylene (CH2 = CH2) of the addition reaction and polymerization reaction, by repeating the-CH2-unit connections made of high polymer chain. It depends on the performance of polyethylene polymerization; in the medium pressure (15-30 atm) under the conditions of organic compounds catalyzed Ziegler-Natta polymerization of high-density polyethylene (HDPE). Polymerization under these conditions is linear polyethylene, and the molecular chain is very long, the molecular weight of up to hundreds of thousands. If it is in the high pressure (100-300MPa), high temperature (190-210 C), under the conditions of peroxide catalyzed free radical polymerization, produce is low-density polyethylene (LDPE), which is branched structure.
Polyethylene does not dissolve in water, water absorption is very small, is of some chemical solvents such as toluene, acetic acid, and only when the temperature is slightly above 70 ℃ to dissolve. But particles like polyethylene, can be between 15 ℃ ~ 40 ℃ of temperature melting or freezing, melting temperature increases, the absorption of heat; solidification temperature decreases, heat. Water is very small and because it is difficult to wet, the insulation performance, it is a good building materials.
Physical and Chemical Properties
Appearance: resilient, resinous particles or powder, white, wax flavor.
Relative density (water = 1):
Relative density (Air = 1):
Saturation vapor pressure (kPa):
Solubility: floating in water, insoluble.
Critical temperature (℃):
Critical pressure (MPa):
Heat of Combustion (kj / mol):
Avoid contact with the conditions:
Building Regulations fire classification:
Flash point (℃): 231 ℃
Ignition temperature (℃):
Explosive limit (V%):
Upper explosive limit (V%):
Hazardous characteristics: strong oxidant and can cause a fire and explosion. And fluoride, xenon tetrafluoride contacts violent reaction. And nitric acid, sodium chloride, three nitromethane not compatible.
Combustion (decomposition) products:
Fire fighting methods:
Packing and Storage
Packaging and marking of dangerous goods:
Handling Information: ERG Guide: 171 ERG Guide Category: Substances (low to moderate hazard)
Health hazards: IARC rating: 3 groups, animal sufficient evidence; human lack of evidence
Skin contact: Remove and isolate contaminated clothing and shoes. Ensure that medical staff understand the individual protection of the substance-related knowledge, attention to self protection.
Eye contact: If skin or eye contact with the substance, immediately flush with water at least 20min.
Inhalation: Move patient to fresh air, seek medical attention. If the patient is not breathing, give artificial respiration. If breathing is difficult, give oxygen.
Properties have been purpose
PE is the oldest high-density linear PE, launched in 1957. Characterized by density of 0.940 or more, with rigidity, toughness, good resistance to environmental stress cracking resistance (ESCR) and low temperature performance.
And widely used in many major markets. Some examples are packaging, blow molding, molded parts, extruded pipe, profiles, and rotational molding large hollow products.