Polymer Used As Body Armor - Para-aramid

In the history of the development of polymer fibers in the world, the discovery of poly-para-aramid (para-aramid) is considered to be a very important historical process [1]. Its significance lies in:

1) Technically, it is the first fiber produced by the new polymer liquid crystal spinning technology, which has guiding significance for the development of subsequent fibers;

2) Due to its excellent mechanical properties and high temperature resistance, it greatly enriches the application fields of man-made fibers. This paper mainly introduces its development process and wide application.

 Overview of para-aramid

Aramid is a synthetic aromatic polyamide [2]. The FTC has adopted a simple definition of aramid as at least 85% of the amide bonds in an aramid are directly attached to two aromatic rings. Para-aramid is a kind of aramid, named after the amide group in the para-position of the benzene ring in its structural formula. Due to the presence of conjugated benzene rings in the main chain of para-aramid, the molecular chain segments are not prone to internal rotation, thus presenting a linear rigid structure, which also makes it have the characteristics of high strength, high modulus, and thermal stability that ordinary fibers do not have. Finally opened up its field of application.

The research and development process of para-aramid fiber

The discovery of para-aramid and subsequent application development are inseparable from DuPont of the United States [2]. As early as 1945, with the commercialization of nylon fiber and the development of polyester fiber, DuPont's leadership formulated a long-term development plan, hoping to develop a fiber with ultra-high strength and high temperature resistance in subsequent production. of fiber. In the 1960s, DuPont's improvement of the low-temperature solution polymerization method and the research on the dissolution process of insoluble polymers promoted by inorganic salt solutions laid the foundation for the birth of aramid. Then in 1972, DuPont solved the problem of para-aramid Spinning problems, thus launching a commercial para-aramid and named it Kelvar.

The research and development of para-aramid fiber in various countries is not far behind, and similar products have been launched one after another. Japan's Teijin Corporation began to produce its own para-aramid fiber in 1972 and named it Technora. The para-aramid fiber product launched by AkzoNobel in the Netherlands was named Twaron in 1986. South Korea's Kelon Corporation began research and development in 1979 and 2005. Achieve industrial-grade production. Russia built a production line as early as 1985. The product was called Terlon, but later it turned to heterocyclic aramid. Its main models are Armos, SVM and Rusar.