Degree of Polymerization, Spiral Structure, and Strength of Cotton Fiber

Abstract

Cotton fiber from bolls collected on opening and dried in the laboratory without exposure to direct sunlight were tested for the following fiber properties: fiber length, fineness, strength, spiral structure, and degree of polymerization (D.P.). When these individual properties were each correlated with the Pressley strength index in simple correlations, the spiral structure and Pressley strength index gave the highest r values, and the degree of polymerization and Pressley index the second highest. For variety effects, the D.P. and Pressley index gave a higher coefficient of correlation than the spiral structure and Pressley index. Significant r values were obtained between fineness and Pressley index for total and variety effects, between fineness and D.P. for all effects, and between spiral structure and D.P. for all effects. Further more, a significant r value was found when fiber length was correlated with chain length (D.P.) for total over-all effects. It is concluded that the length of the cellulose molecule (D.P.) is an important factor in the physical properties of cotton fibers. All multiple correlations, including the fiber properties used in the simple correlations, were highly significant for varieties within locations and for over-all effects. Spiral structure and chain length (D.P.) when correlated with Pressley strength gave the highest coefficient of correlation.