INFLUENCE OF STRUCTURE AND MOISTURE ON COTTON FIBER PROPERTIES
Location: Cotton Structure and Quality Research
Project Number: 6435-44000-076-00
Start Date: Jul 28, 2010
End Date: Jul 27, 2015
Objective 1: Develop new or improved industry-supported methods to measure moisture in cotton fiber.
Sub-objective 1a: Develop and implement accurate reference methods to replace the existing standard oven-drying methods to alleviate the biases in the latter methods.
Sub-objective 1b: Develop more accurate techniques to measure the “free” and “bound” water contents in cotton for use in understanding which quality indicator correlates best with the fiber properties.
Objective 2: Determine the bases for the interaction of moisture with cotton structures and resulting fiber properties.
Sub-objective 2a: Determine the structures and interactions of cotton cellulose crystals and amorphous regions at the molecular level.
Sub-objective 2b: Determine the impact of moisture interaction/moisture levels on fiber physical properties and on the transport properties of moisture between cotton fibers.
Sub-objective 2c: Improve the understanding of factors that control molecular shape and reactivity for cotton.
This research is a comprehensive effort to optimize the measurement of the amount of water in cotton fiber by both reference and rapid, indirect methods, to understand the structural bases for the interaction of water with cotton, to determine the implications of water for cotton performance properties, and to develop means of optimizing the effects of water on cotton performance. The first objective develops a more accurate measure of the water in cotton fiber. Karl Fischer Titration (KFT) and Low Temperature Distillation (LTD) techniques will be used to develop new fiber reference moisture methods. Solvent extraction techniques, followed by the KFT method for moisture, will be used to separate and measure the free water and bound water fractions of the total moisture level. The second objective develops a deeper understanding of fiber structure at the molecular, crystallite, and microfibrillar levels, how water interacts with, and moves within, these entities, and how these levels are affected by water. Theoretical and experimental molecular modeling and X-ray diffraction studies will be used to characterize and establish new structural features. A large number of rapid moisture measurement techniques (chemical, electric, spectroscopy, gravimetric) will be compared to the present oven and new reference moisture methods. Environmentally controlled chambers, in combination with sensors, will be used to monitor moisture transport through a specified mass/density of cotton fiber and to characterize moisture impacts (e.g., strength/ breakage) on cotton fiber by varying the relative humidity and temperature. Light and electron microscopy and molecular spectroscopy will be used to monitor changes in structure and breakage patterns with moisture.