paraaramidid

Paraaramids are a class of strong, heat-resistant synthetic fibers. They are characterized by the presence of para-oriented aromatic amide linkages in their polymer backbone. This specific chemical structure is responsible for their exceptional mechanical properties. The most well-known paraaramid is Kevlar, developed by DuPont in the 1960s. Another significant paraaramid is Twaron, produced by Teijin.

These fibers are synthesized through a complex chemical process, often involving the polymerization of aromatic diamines with aromatic diacid chlorides. The resulting liquid crystalline solutions are then spun into fibers, which are subsequently drawn to align the polymer chains and enhance their strength. The rigid, rod-like structure of the paraaramid molecules allows for strong intermolecular forces, contributing to the high tensile strength and modulus of the fibers.

Paraaramids possess several desirable properties including high tensile strength, excellent toughness, low elongation, good chemical resistance, and high thermal stability. They do not melt but rather char at high temperatures. Their resistance to degradation from UV radiation and certain chemicals is also notable.

The unique combination of strength and heat resistance makes paraaramids highly versatile. They are widely used in applications requiring protection and durability, such as body armor, bulletproof vests, aerospace components, ropes, and reinforcement for tires and industrial belts. Their light weight also makes them attractive for ballistic protection and high-performance sporting goods.