the dialdehyde microfibrillated cellulose/poly(vinyl alcohol) (DAMFC/PVA) composite hydrogels were investigated
with easily controlled mechanical strength. DAMFC/PVA hydrogels were prepared by the acetal reaction occurred between the aldehyde groups on the surface of DAMFC microfibers and the hydroxyl groups on the PVA macromolecular chains. Then the hydrogels were soaked in various salt solutions. Due to the acetal reaction
the reinforcement DAMFC and the matrix polymer PVA were connected by covalent bonds. Under the stress
the load could be efficiently transferred from the reinforcement to the matrix
so that the mechanical strength of the composite hydrogel was significantly improved. In addition
due to the salting out effect
the mechanical strength of the hydrogels was further improved by soaking in salt solutions. The anion species of the salt had a great influence on the mechanical strength. By regulating the content of DAMFC
the oxidation time of NaIO
4
and the selection of anion in salt solution
the mechanical strength of PVA composite hydrogels can be regulated in a wide range to meet the needs of different applications.