Produção e caracterização de polieletrólitos catiônicos derivados da celulose

Abstract

Polymers are materials present in almost all areas of human performance. However, many polymers come from non-renewable sources and can generate toxic waste in their processing, which harms the environment. A more sustainable alternative is to replace these materials with others that are environmentally appropriate. Biopolymers are natural and biodegradable materials, so they are an attractive substitute for synthetic polymers. Cellulose is the most abundant biopolymer on earth. It is present in the cell wall of most vegetables as an important structural component. It is a linear, neutral polymer with high molar mass and has crystalline regions and also strong inter- and intramolecular hydrogen bonds. Due to such characteristics the processing of the cellulose becomes difficult. Polyelectrolytes are generally synthetic polymers and employed in various areas such as: effluent treatment, paper production, in the chemical, food, cosmetic and pharmaceutical industries, petroleum and textile industries. These materials have loads throughout their structure, and can be cationic, anionic or amphoteric. In this work, several sources of cellulose, such as sugarcane bagasse, commercial cellulose acetate and commercial methylcellulose were tested in order to carry out their solubilization and then react with a quaternizing agent to give a polyelectrolyte cationic surfactant that is biodegradable. The quaternizing agent was 2,3-epoxypropyltrimethylammonium chloride (ETA). From the sources tested, only sugarcane bagasse pulp, which had been previously treated to reduce its molar mass (CBCA/AD), was solubilized by the LiOH/urea solvent system. After the quaternization or cationization reaction of this sample, the material was soluble in water at room temperature. For the quaternization reaction using commercially available methylcellulose (MCC), which is a water-soluble cellulose-derived material, the reaction product of this material (MCC) with ETA was also soluble in water at room temperature. In addition to the solubility, the samples were characterized by X - ray diffraction, infrared spectroscopy (FTIR) and the cationized CBCA/AD sample was also characterized by 13C nucler magnetic resonance. The characterization of the materials indicated the substitution of hydroxyl (OH) groups of cellulose/methylcellulose bycationic groups, evidencing the successful production of cationic polyelectrolytes derived from cellulose.