Polyethylene resin is a non-toxic, tasteless white powder or granule, the appearance is milky white, there is a wax-like feel, low water absorption, less than 0.01%. The polyethylene film is transparent and decreases with the increase of crystallinity. Polyethylene film has low water permeability but large air permeability, which is not suitable for fresh-keeping packaging but suitable for moisture-proof packaging. Flammable, oxygen index of 17.4, low smoke when burning, a small amount of molten droplets, yellow and blue on the flame, paraffin smell. Polyethylene has good water resistance. The surface of the product is non-polar, difficult to bond and print, and the surface treatment has been improved. There are many branched chains, and their light degradation and oxidation resistance are poor.
Its molecular weight is in the range of 10,000~100,000. Those with a molecular weight of more than 100,000 are ultra-high molecular weight polyethylene. The higher the molecular weight, the better its physical and mechanical properties, the closer it is to the required level of engineering materials. However, the higher the molecular weight, the more difficult it is to process. The melting point of polyethylene is 100~130 °C, and its low temperature resistance is excellent. It can still maintain good mechanical properties at -60 °C, but the use temperature is 80~110 °C.
Insoluble in any known solvent at room temperature, above 70 °C can be dissolved in toluene, amyl acetate, trichloroethylene and other solvents.
