| Abstract: | The drawing behavior and mechanical properties of gel-spun nylon 6 fibers were investigated in relation to the growth rate and morphology of gels. The sol-gel transition temperature of a nylon 6/benzyl alcohol solution increased with polymer concentration and, at higher concentration, appeared with gel melting. From the measurements of gelation time, the growth rate of gels was estimated assuming an Arrhenius type of gelation rate. It was found that gel growth of nylon 6 in benzyl alcohol was nearly three-dimensional, evidenced by the presence of spherical gels observed in the scanning electron microscope. A draw of asspun fibers was performed at one-stage or two-stage hot drawing. Modulus and tenacity increased with increase of the draw ratio and were nearly independent of the draw temperature. A two-stage draw was more effective to obtain a higher modulus than that of the one-stage draw and it was ascribed to the difference in the molecular orientation mechanism. However, it was difficult to obtain a higher modulus than 6.2 GPa by the gel-spinning of nylon 6 in this study and it was regarded as a result of the presence of spherical gels which hindered the sample to elongate to a higher draw ratio. © 1996 John Wiley & Sons, Inc. |
