Polyolefin Fibers and Polymer Structure'

Abstract

The polyolefins (or, more restrictedly, the poly-alpha-olefins) are a growing family of polymers which comprise the straight linear polyethylene or polymethylene and its derivatives. Their fiber-forming properties are based on the paraffinic backbone com mon to all these polymers; the derivatives can have an infinite variety of structures, and this has an extremely pronounced influence upon the fiber properties. Present polymerization chemistry and technique permit close control of these structures to a high degree of purity and in turn the control of the fibers processed therefrom. Length and distribution of the molecular chains, their stereospecific configurations, and crystallinity and its degree are shown in their effect on the polyethylenes (low to high density) and on polypropylene, and future developments are foreseen. The case of the polyolefin fibers is not that of "one more" synthetic fiber ; the polyolefins may well become the classical, even textbook example of the intricate relationship between molecular structure and fiber properties. As a new textile material the polypropylene fiber is of particular interest economically and in its characteristics—all the more so as problems such as ultraviolet stability and dyeability are being overcome.