Green Solvents in the Chemistry of Biopolymers: Synthesis of New Ionic Liquids and their Application in Cellulose Derivatization

• Grant number: 09/14349-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2010
• End date: December 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Organic Chemistry
• Principal Investigator: Omar Abou El Seoud
• Grantee: Romeu Casarano
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 04/15400-5 - Synthesis, properties and applications of tensoactives and functionalized bio-polymers: a green chemistry approach, AP.TEM

Abstract

In the last decades, the development and use of natural polymers have attracted increasing interest due to growing consumption of non-renewable resources. As the largest source of renewable biological resources, cellulose has been widely used in industrial applications in order to obtain fibers, films, membranes, biodegradable materials, food additives, etc. The dissolution of cellulose is of fundamental importance to (i) its processing to obtain regenerated cellulose and (ii) its derivatization in a controlled and reproducible manner. In this context, ionic liquids have been suggested as promising green solvents for the dissolution and chemical modification of cellulose in homogeneous medium.The focus of the present research project in is green chemistry, as the starting material (cellulose) is renewable and the products of derivatization (esters and ethers) are biodegradable, the solvents and excess reagents will be recycled in the process. The main objectives are: (i) To obtain cellulose esters, mixed esters, and ethers in homogeneous medium, using ionic liquids (ILs) as reaction medium, via a green approach (e.g., recycling of solvents); (ii) To investigate the effects of the characteristics of cellulose on its reactivity in the derivatization reactions. The parameters of interest include DS, Ic, surface area of cellulose, and its nature (microcrystalline or fibrous); (iii) To investigate the ILs as solvents, as compared to conventional solvents, LiCl/DMAc and R4N+F-/DMSO; (iv) To study the kinetics of esterification of cellulose by means of instrumental analysis.