Molecular weight of cellulose and its organization at different stages of cotton fiber development

There is a continuous change in cell wall composition and organization during cotton fiber development. Cotton fiber<br>strength correlates to the molecular weight (MW) and molecular weight distribution (MWD), and organization of<br>cellulose chains in the secondary cell wall. These parameters change drastically during fiber development. This study<br>reports on the MW, MWD, and organization of cellulose in cotton fibers harvested from two cotton cultivars of<br>Gossypium hirsutum L., (Texas Marker-1 and TX55) at different levels of maturity. Fiber dissolution is necessary to<br>estimate the molecular properties of cellulose. Cellulose in mature cotton fibers is larger in MW and highly crystalline<br>and, therefore, poorly dissolves in common solvent systems. To facilitate the dissolution, fibers were first pretreated with<br>23% sodium hydroxide and then dissolved in a dimethylacetamide/lithium chloride solvent system. Gel permeation<br>chromatography of dissolved fibers indicated th