PA66 is a translucent or opaque milky white crystalline polymer. It emits purple-white or blue-white light when exposed to ultraviolet light. Its crystal form has both a-type and b-form forms. It is triclinic at normal temperature and above 165 °C. It is a hexagonal crystal form. PA66 has a Tg of 65 ° C and a melting point of 260-265 ° C. It is a high melting point of aliphatic polyamide and can maintain good performance over a wide temperature range. The heat distortion temperature is 70 degrees, but if it is added 30 % glass fiber can jump to 250 ° C.
PA66 has good insulation properties, large computer resistance and surface resistance, and is widely used as an insulating device in power transmission systems (such as railway insulation). However, the various electrical properties of PA66 are significantly reduced as the temperature rises and the water absorption increases, so the modified product is often used.
PA66 is also well tolerated at high temperatures for lubricants, oils, hydraulic shafts, coolants, refrigerants, paint solvents, detergents, detergents, aliphatic and aromatic solvents, and other solvents. Corrosion by inorganic acids, certain oxidizing agents, chlorinated solvents and heavy metal salts, care should be taken when using them.
PA66 has high strength, hardness, stiffness and creep resistance, and has excellent fatigue resistance. Therefore, PA66 can be used for gears, hair, etc., to reduce the loss of fracture or mechanical properties under cyclic stress or vibration stress. Also because of the water absorption, the long-term strength of PA66 decreases with the increase of moisture content. PA66 has good compressive stress and high compressive modulus in polyamide. The toughness of PA66 is very good, but it is sensitive to the notch. The chemical of PA66 The physical properties are very similar to those of polyamide 6, so the modification method is also close. For example, modification of PA66 with glass fiber can enhance its hardness, strength, creep resistance and fatigue resistance, and reduce water absorption to improve dimensional stability; Carbon black can improve the weatherability of PA66.
