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Browsing by Author "Andrade, Carlos A."

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    Phase separation spinning of polypropylene fibers
    Andrade, Carlos A. (Virginia Polytechnic Institute and State University, 1972)
    Polypropylene fibers were spun from solutions of different polymer contents undergoing phase separation. The range of concentrations used was 25 to 60 wt. % polypropylene. The solvent used was naphthalene. After the naphthalene was extracted from the fibers using diethyl ether the fiber's properties were measured. Deniers and diameters of the fibers varied inversely with the spinning draw ratio. The fibers had void fractions ranging from 0.20 to 0.70. The porosity of the fibers was inversely proportional to the polymer contents of the spinning solution. Tenacities and moduli ranging from 1.5 to 8.5 and from 6 to 17 grams per denier, respectively, were measured after the fibers were cold drawn 4/1. These values varied directly with spinning draw ratio. Percent elongation at break of fibers spun from solutions of polymer contents greater than 35 wt. % polypropylene varied inversely with draw ratio. Fibers spun from solutions of less are 35 polymer contents showed elongations at break which varied directly with draw ratio for draw ratios of less than about 1500. For higher draw ratios and inverse relationships were observed. The fibers exhibited good hand bulk, and self-coiling and crimping characteristics.