The PP duct has high crystallinity and regular structure, and thus has excellent mechanical properties. However, at room temperature and low temperature, the impact strength is poor due to the high degree of molecular structure regularity. The more outstanding performance of the PP pipe is the resistance to bending fatigue, commonly known as the hundred-fold adhesive.
The PP air duct has good heat resistance, and the product can be sterilized and sterilized at a temperature of 100oC or higher, and is not deformed at 150oC under the condition of no external force. The embrittlement temperature is -35oC, embrittlement occurs below -35oC, and the cold resistance is not as good as polyethylene.
The chemical stability of the PP duct is very good. Besides being attacked by concentrated sulfuric acid and concentrated nitric acid, it is stable to various other chemical reagents. However, low molecular weight aliphatic hydrocarbons, aromatic hydrocarbons and chlorinated hydrocarbons can soften the PP pipe. And swelling, and its chemical stability with the increase of crystallinity is also improved, so PP pipe is suitable for the production of various chemical pipes and fittings, anti-corrosion effect is good.
The PP duct has excellent high-frequency insulation performance, and since it hardly absorbs water, the insulation performance is not affected by humidity. It has a high dielectric constant and can be used to make heated electrical insulation products as temperature rises. It also has a high breakdown voltage and is suitable for use as an electrical accessory. It has good resistance to voltage and arc resistance, but it has high static electricity and is easy to age with copper.
The PP duct is sensitive to ultraviolet light, and the addition of zinc oxide, dilauryl thiodipropionate, carbon black or similar white filler can improve its aging resistance.