The Dependence of Stiffness and Strength of Gossypium hirsutum Cotton on Crystallite Orientation

Abstract

The crystallite orientation angle obtained from x-ray diffraction patterns can be used for varietal characterization of cotton at the molecular level. The 40 and 50% x-ray angles are usually taken as representative parameters to correlate with the strength of the fiber. Although the 50% x-ray angle has some theoretical justification, like the use of the half-width of spectral lines, the choice of the 40% x-ray angle is arbitrary. From the study of 24 Gossypium hirsulum cotton varieties reported in this paper, it is observed that the average angle of orientation αm evaluated from the Hermans orientation factor fc gives better correlations with mechanical properties than the 40 and 50% x-ray angles con ventionally used.

Dependence of Stiffness and Strength of Cotton Fibers on Crystallite Orientation

“…Our initial studies [3] on 11 cotton varieties of mixed species showed that the Hermans orientation factor gave the highest correlations. This was then extended to 24 varieties of Gossypium hirsutum species and the conclusion was confirmed [9]. The investigations have been further extended to another 24 varieties of the Gossypium arboreum species, and the results on these samples, along with the results for Gossypium hirsutum species, are presented in this paper.…”

“…While some workers found the 40% X-ray angle has higher correlation with mechanical properties [ 1,2,5,14,15], others have found the 50% Xray angle, or even the 75% X-ray angle is superior [ 1,3] in this respect. Some workers obtained relatively high correlations [3,7,9,13] with the Hermans orientation factor.…”

“…The samples were purified using our standard purification techniques [9]. CHARACTERIZATION Details of the characterization techniques are given elsewhere [3], only a brief description is given here.…”

The correlation between X‐ray orientation parameters and strength of fibers in native cotton

“…[36][37][38][39][40][41][42][43] postulated that the Hermans factor and the average angle of crystallite orientation a, deduced from it is the best index for varietal characterization of cotton fiber strength and is recommended to be used in cotton breeding. Although there is some theoretical justification for the use of the 50% X-ray angle as the half-width of a spectral line intensity peak in spectroscopy, the choice of 40, 75, and other X-ray angles is purely a r b i t r a r~.~~,~~…”