Application of green technologies on the development of starch cellulose acetate strucutures

Starch-based blends present an enormous potential to be widely used in the biomedical area, because they are totally biodegradable, inexpensive, available in large quantities. However, natural-based polymers have great limitations in processability particularly due to their usually high crystallinity which limits their solubility. This can be overcome by the use of ionic liquids which are recognized as ‘green’ replacements for conventional organic solvents, dissolving some natural macromolecules such as cellulose, starch, chitin, chitosan, silk fibroin, wool keratin, as well as lignin) . Furthermore, they present unique physicochemical properties, namely lower vapour pressure, excellent chemical and thermal stabilities, high ionic conductivity and easy recyclability . 

Starch based materials have been proceed in a variety of different morphologies and shapes by a number of different processes. In this work starch/cellulose acetate (SCA) was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in different non-solvents (water, ethanol and isoprophanol) in order to obtain membranes. Different concentrations of CA (5 and 10%) in ionic liquid and drying techniques (vacuum oven and freeze drying) were also studied. The starch/cellulose acetate structures were posteriorly examined by scanning electron microscopy to evaluate the morphological features.

The development of innovative technology suchas novel natural polymers materials is of grater interest in medical field. The obtained structures (membranes) present high biomedical potential as these can be used in several applications, for instance drug delivery, skin substitutes, guided bone regeneration or as coatings for medical devices.