Evaluation on reinforcing effect of cellulose nanocrystals in starch films produced by continuous casting

Abstract

The growing accumulation of non-biodegradable plastic waste in the environment has motivated research toward the development of biodegradable materials from renewable sources. Starch is a natural polymer that has a good potential for biodegradable plastics production, because it is cheap and abundant, however, physical properties of starch plastics, such as water barrier and mechanical properties, are inferior to those of most commercial plastics. This proposal is aimed at developing starch biodegradable plastics reinforced with cellulose nanocrystals using continuous casting, an emerging scaled-up polymer solution casting technique. The main hypothesis is that inclusion of highly dispersed cellulose nanocrystals will extend the mechanical and barrier properties of continuously cast starch films. Commercial cellulose nanocrystals will be characterized with respect to their morphology and dimensions, and later incorporated into starch films. Different concentrations of nanocrystals (1 - 5%) and plasticizer will be evaluated in this project. The starch/cellulose nanocrystal nanocomposites will be studied by electron microscopy, thermogravimetry, tensile tests, optical analysis, among other techniques. Correlations between size and dispersion state of nanocrystals within the starch film matrix and properties of nanocomposites will be established. Finally, the properties of the starch/cellulose nanocrystal nanocomposites will be compared with those of non-biodegradable plastic films in order to describe their market potential. (AU)