ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
In the course of our investigations into the relation between draw ratio (i.e., the permanent extension ratio imparted during manufacture) and birefringence of man-made fibers, we found that the relation published by Kordes et al. for Perlon (nylon 6) has equivalents for several different fibers that may be considered as special cases of one general empirical relation. This empirical relation, expressed in differential form, reads \documentclass{article}\pagestyle{empty}\begin{document}$ d(\Delta n)/d(\ln \lambda) = m + p\Delta n $\end{document} where Δn = specific birefringence of the fiber, In λ = the natural logarithm of the permanent extension ratio, reckoned from the isotropic state, and m and p are constants. The constant m can assume positive or negative values, according to the sign of the birefringence of the fiber. The values found for p appear also to be characteristic of the polymer. It also appears that the experimental results can be described within experimental error by taking for p multiples of 1/2. This opens the possibility for a comparatively simple way of plotting the results. Thus, apart from the value p = -1/2 corresponding to Kordes' relation, for p the following values, which are multiples of 1/2, viz., -1, -1/2, +1/2, +1, have been found by us (e.g., respectively for nylon 66, polyethylene, polyethylene terephthalate, viscose rayon). These seem to be preferred values of p. So far no case has been found of the values p = 0 and p 〉 ±1. As yet there is no theory forthcoming to explain the empirical relation in its general form nor the apparent rule of preference for the above-mentioned values of p.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1959.1203412750
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