Polyamide-6 has chemical and physical properties similar to nylon 66, however, it has a lower melting point and a wide process temperature range. It has better impact and dissolution resistance than nylon 66 plastic, but is also more hygroscopic. Because many quality characteristics of plastic parts are affected by hygroscopicity, it is important to take this into account when designing products using nylon 6.
In order to improve the mechanical properties of nylon 6, various modifiers are often added. Glass is the most common additive, and sometimes synthetic rubbers such as EPDM and SBR are added to improve impact resistance.
The biggest feature is that under long-term load, it has excellent dimensional stability and outstanding electrical insulation, a wide temperature range, and can be used for a long time in the range of -127~121℃ . The product has high tensile strength and impact strength, and good creep resistance. In addition, the dielectric properties of PPO rank first among plastics, and are hardly affected by temperature and humidity. The deformation temperature under load can reach above 190℃.
The molecular structure of PPS is relatively simple. The main chain of the molecule is alternately arranged by benzene rings and sulfur atoms. A large number of benzene rings give PPS rigidity, and a large number of thioether bonds provide flexibility. Symmetrical molecular structure, easy to dry crystallization, non-polar, good electrical properties, no water absorption.
There are two main disadvantages of polypropylene, one is that the shrinkage rate is large, which leads to poor dimensional stability of the product, which is prone to warping deformation, and the other is that it is easy to break at low temperature. Of course, compared with traditional engineering plastics, there are still disadvantages such as low modulus, poor heat resistance, poor light resistance and thermal aging properties.
PP material, through inorganic filling, elastic toughening, adding glass fiber and other modification methods, improves the strength, rigidity, heat resistance and dimensional stability of general PP, mainly used in To manufacture high-strength, high-heat-resistance products such as automotive dashboards, door inner guards, water tank masks, engine bellows, and bumpers.