ARS | Publication request: Application of Cellulose Microfibrils in Polymer Nanocomposites

Submitted to: Polymers And The Environment
Publication Acceptance Date: July 22, 2004
Publication Date: August 22, 2004
Citation: Orts, W.J., Shey, J., Imam, S.H., Glenn, G.M., Guttman, M.E. 2004. Application Of Cellulose Microfibrils In Polymer Nanocomposites. Polymers And The Environment.

Interpretive Summary: Considering the increased legislation limiting the burning of rice and wheat straw, and the difficulty in dealing with agricultural surplus, new composites are being developed that use the unique fiber properties of ag-based microfibrils. Microfibrils obtained by the acid hydrolysis of cellulose fibers were added at low concentrations (2-10% w/w) to polymer gels and films as reinforcing agents. Significant improvements in mechanical properties were obtained for fibrils derived from several cellulosic sources, including cotton, softwood, and bacterial cellulose. For extruded starch plastics, the addition of cotton-derived microfibrils at 10.3% (w/w) concentration increased Young's modulus by 5-fold relative to a control sample with no cellulose reinforcement. Preliminary data suggests that shear alignment significantly improves tensile strength. These developments imply that composites derived from organic ag-derived products may show similar benefits to those from clay-based inorganic nancomposites.

Technical Abstract: Cellulose microfibrils obtained by the acid hydrolysis of cellulose fibers were added at low concentrations (2-10% w/w) to polymer gels and films as reinforcing agents. Significant changes in mechanical properties, especially maximum load and tensile strength, were obtained for fibrils derived from several cellulosic sources, including cotton, softwood, and bacterial cellulose. For extruded starch plastics, the addition of cotton-derived microfibrils at 10.3% (w/w) concentration increased Young's modulus by 5-fold relative to a control sample with no cellulose reinforcement. Preliminary data suggests that shear alignment significantly improves tensile strength. Addition of microfibrils does not always change mechanical properties in a predictable direction. Whereas tensile strength and modulus were shown to increase during addition of microfibrils to an extruded starch thermoplastic and a cast latex film, these parameters decreased when microfibrils were added to a starch-pectin blend, implying that complex interactions are involved in the application of these reinforcing agents.