Their results suggest that pectins and xylans take on a larger role in the absence of xyloglucan; furthermore they proposed a cell wall model where crosslinks formed by xyloglucan are not present as a load-bearing fibril extended between cellulose fibres, but that the Sorafenib mechanical effect of XG is limited to a small fraction that effectively binds regions of cellulose microfibrils SCH727965 together. In our studies the presence of xyloglucan increased the mechanical strength or resistance to compression at all strain rates tested. CXG composites were able to withstand compression strengths at least 3 times larger than C; this effect was even more pronounced at fast strain rates showing an effective modulus up to 8 times larger. Similar behaviour under compression has been reported for other cellulose composites containing polyacrylamide. In contrast to the increase in modulus under compression, CXG composites are much weaker than cellulose alone under uniaxial or biaxial tension. This difference in behaviour of xyloglucan composites under compression and tension is due to the orientation of the cellulose microfibrils and differences in how the water can flow out of the structure under load. Under the compression test studied here, water can only flow out of the sides of the hydrogel disks which have a low surface area and porosity whereas in tensile tests water can flow from all surfaces of the test pieces. Hence the contribution of fluid confinement to the deformation is negligible in tensile tests, while under the compression tests reported here water raises the internal pressure of the system which increases significantly the apparent stiffness of the cellulose hydrogel. As shown by the near-zero Poisson ratio, under the compression test there is no significant radial extension of the hydrogel which indicates that the network exhibits greater resistance to deformation in the longitudinal direction of the fibres. During compression the fibres may buckle, bend or slip at connexion points due to cellulose entanglements or xyloglucan crosslinks. In CXG, SEM and mechanical tests suggest that xyloglucan crosslinks have less resistance to compression compared to cellulose entanglements, allowing the cellulose fibres to collapse onto each other increasing the density and compression strength of the network. In addition, the presence of the hemicelluloses might affect the interstitial fluid drag, raising the internal pressure caused by water and increasing the stiffness of the composites; this effect would be more apparent at fast compression speeds, as is observed. In clear contrast to xyloglucan, the presence of arabinoxylan did not affect the micromechanical behaviour at slow strain rates /long time scales, but did at short time scales.