Wide‐angle X‐ray diffraction studies of nylon–ionomer blends

摘要

AbstractBlends of nylon 6 with poly(acrylic acid) polyacrylamide, poly(ethylene‐co‐acrylic acid), poly(ethylene‐co‐vinyl alcohol), poly(acrylamide‐co‐acrylic acid), and polypropylene were prepared by melt blending. Annealing treatments included treatments in Vacuum, in water, and in 20 formic acid at various temperatures. WAXS (wide‐angle X‐ray scattering) patterns of melt chips and of undrawn, drawn and textured yarns were obtained. The melt chips of 100 nylon 6 crystallize in the α form while the chips of all the blends exhibit a single diffracton ring. All the blends behave similarly during different annealing treatments. When annealed in 20 formic acid at 102°C, the α structure results. The as‐spun fibers of nylon 6 and of the blends with poly(acrylamide‐co‐acrylic acid) and poly(ethylene‐co‐vinyl alcohol) exhibit a broad diffraction maximum in the region 2θ = 19–25°. The α content and its purity increase with increasing severity of the annealing treatment. The as‐spun fibers of the blend with poly(acrylic acid), on the other hand, exhibit a highly oriented γ structure which is highly resistant to conversion to the α from during the annealing treatments. Only when treated in 20 formic acid at 102° does the pure α form result. The drawn textured yarns of nylon 6 exhibit both the α and the γ forms. However, the γ content of the textured yarns from the blends varies with the type and concentration of the additives. The textured yarns from the blends with low levels (0.125) of poly(acrylic acid) have a very high α content. It is very unusual that the as‐spun fibers with almost pure γ structure, when dr