New Insights into Fibre Swelling, Interfibre Bonding and Wet Strength

Abstract

The various modes in which ordinary and modified cellulose fibres and surface modified cellulose microfibrils can interact with water are reviewed. The hydrogel state of fibres can be extruded and dried to form a continuous oriented strand: ‘one dimensional paper’. A colloidal suspension of surface modified cellulose microfibrils can be converted into a paracrystalline gel which exhibits birefringent domains and responds to extrusion through a cylindrical orifice to yield a continuous fibre whose density and x-ray diagram are characteristic of cellulose: ‘reconstituted native cellulose’. The mechanical properties of these two novel materials are reported. The mechanism of wet strength development in ‘one-dimensional paper’ which had been encapsulated with nascent polyethylene was studied. The polyethylene was confined to the exterior of the substrate and while it does not prevent fibre wetting and swelling the rate of wetting is considerably slowed. As a result, disruption of interfibre bonds is incomplete.