  We present numerical simulations of a model of cellulose consisting of long
stiff rods, representing cellulose microfibrils, connected by stretchable
crosslinks, representing xyloglucan molecules, hydrogen bonded to the
microfibrils. Within a broad range of temperature the competing interactions in
the resulting network give rise to a slow glassy dynamics. In particular, the
structural relaxation described by orientational correlation functions shows a
logarithmic time dependence. The glassy dynamics is found to be due to the
frustration introduced by the network of xyloglucan molecules. Weakening of
interactions between rod and xyloglucan molecules results in a more marked
reorientation of cellulose microfibrils, suggesting a possible mechanism to
modify the dynamics of the plant cell wall.
