Cellulosic nanofibre composites

Cellulosic nanofibres were made from sulphite bleached softwood using mechanical action. Fibre dimensions were evaluated with FE-SEM. The average diameter was found to be below 100 nm. Composites containing up to 50% of these cellulosic nano fibres and starch were prepared using a wet film casting method. Three routes for preparation were evaluated for their effect on mechanical performance of the resulting films. All resulting films were translucent and showed an increase in strength of a factor of 1.5 larger than for conventional flax-PP composites. The failure strain remained at the same level. Nanofibre inclusion did not result in a significant effect on the oxygen barrier properties of starch films up to at least 30 wt.% fibre in starch. Furthermore, the sensitivity of starch to water was reduced. Barrier properties against O2 and H2O were improved by addition of 4 wt.% of nanoclay. Nanoclay addition up to 4 wt.% had no significant effect on the films strength, stiffness and strain at failur