Preliminary Modulus Calculations for Cellulose

The Young's modulus is a measure of inherent stiffness.  In the case of cellulose, it is the ability to undergo changes in length as tension or compression forces are applied. The modulus can be calculated by performing tension tests on cotton fibers or, as in this study, by stretching molecular models in a computer program. However, considerable disparities between values from tensile tests and molecular modeling calculations are typically observed. With this study we attempt to ascertain the roles of intermolecular hydrogen bonding and other intra- and intermolecular details from molecular models. Thus, modulus calculations with empirical force fields and quantum mechanics are being performed with models containing various (N = 1-7) cellobiose molecules capable of intermolecular hydrogen bonds as well as some analogs that cannot make hydrogen bonds.