A wide‐angle x‐ray method has been developed by which quantitative structural information can be obtained on nylon‐6 yarns. To this end, experimental equatorial diffractometer scans measured in transmission were fitted to a mathematical model describing the profiles as the envelopes of three bell‐shaped functions. Four different models were investigated using, respectively, Gauss, Lorentz (Cauchy), Logistic, and Pearson‐VII functions. The last model, which can be regarded as a generalized Lorentz function, gave the best fit. On the basis of a statistical analysis of the results of well‐separated x‐ray peaks, two parameters could be fixed. Another reduction of the number of parameters was achieved by interrelating the peak areas of the two outer reflections. These reductions widened the applicability of a computer program based on the aforementioned model to highly overlapping x‐ray peaks. So the whole variety of x‐ray scans, which can be obtained from nylon‐6 yarns made under widely varying process conditions, can be well described. The fitting procedures provide unique solutions and hence objectively determined parameters.
synopsisThe free radicals formed on irradiation of nylon 6 have been studied by means of electron spin resonance (ESR). The irradiation WFS performed at liquid nitrogen temperature with wavelengths in the region of Vlar radiation. The spectfum so obtained could best be fitted by sssuming -CHAH-CHz-and -CHz--C-O to be the trapped radicals. The assignment of the spectrum supports the idea that the first step in photodegradation is the breaking of the amide bond. The splitting constant of the a proton of the alkyl radical has been found to be nearly the same for drawn and undrawn yarn. This strongly suggests that the low-energy radiation is capable of breaking bonds only in the unoriented amorphous regions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.