Experimental and modeling investigation of cellulose nanocrystals polymer composite fibers

Chen, Si. Ph.D., Purdue University, May 2015. Experimental and Modeling Investigation of Cellulose Nanocrystal Polymer Composite Fibers. Major Professor: R. Byron Pipes. Cellulose nanocrystals (CNCs) are a class of newly developed and sustainable nanomaterial derived from cellulose-based materials such as wood. There have been substantial research efforts to utilize these materials as reinforcing agents. However, in order to develop CNC nanocomposites with industrial applications, it is necessary to understand how addition of CNCs affect the properties of the polymer nanocomposite. In the present work, several approaches, experimental and theoretical, are presented in an effort to characterize and understand the effect of CNCs on the properties of polymer CNC fibers. Two experimental methods were used to develop cellulose acetate (CA) and CNC composite fibers: electrospinning and dry spinning. Polyvinyl alcohol (PVA) and CNC dry spun composite fibers were also produced in order to study the effect of CNCs in additional polymeric systems. Surface morphology of these fibers was analyzed by scanning electron microscopy and optical microscopy. Elastic modulus, elongation, and ultimate tensile strength were measured by dynamic mechanical analysis. CNC dispersion was assessed by optical microscopy under cross polarizers. 2D X-ray