Extended-chain polyethylene fibers

Extended-chain polyethylene fiber became available commercially in 1984 when DSM, a Dutch firm in the Netherlands, introduced Dyneema , and Mitsui Petrochemicals in Japan announced Tekmilon . Allied Signal of the United States entered the field in 1985 when it introduced Spectra fibers. These materials are characterized by very high strength and modulus, which are achieved by the use of ultrahigh molecular weight polyethylene spun by the gel spinning method into fibers having extended-chain structures and near perfect orientation. 

Extended-Chain Polyethylene Fibers (ECPE) fibers are relatively recent entrants into the high-performance fibers field. Spectra ECPE, the first commercially available ECPE fiber and the first in... 

Cordova, D. S. and Donnelly D. S. 1990. Reinforced Plastics, Extended-Chain Polyethylene Fibers. In 1.1. Rubin, Ed. Hand-bookofPlastic Materials andTechnology (Wiley. Hoboken, NJ). 

Brown, J.R., P.J.C. Chappell, Z. Mathys (1992b). Plasma surface modification of advanced organic fibers, part III. Effects on the mechanical properties of aramid/vinylester and extended chain polyethylene/ vinylester composites. J. Mater. Sci. 27. 6475-6480. 

By variation of the conditions of crystallization (see Sect. 1.3.3.3) polyethylene can be obtained either as folded lamellae, as extended chain crystals (high strength fiber), or as so-called shish kebabs (fibrils with a morphology similar to cellulose). All these variants differ in properties. 

Thus, compared to other polymers, it is easier to obtain an extended and oriented chain structure in polyethylene. High density polyethylene (HDPE) is preferred to other types of polyethylene because HDPE has fewer branch points along its backbone and a high degree of crystallinity. These characteristics of linearity and crystallinity are important to obtain a high degree of orientational order and an extended chain structure in the final fiber. 

---