Antioxidant Polymers by Free Radical Grafting on Natural Polymers

This chapter presents an overview of the different antioxidant polymeric materials, based on natural macromolecules, which can be obtained by employing the free radical grafting procedure. Free radical grafting is a straightforward method which allows the covalent insertion of the antioxidant molecules onto the polymer backbone without the use of organic solvents or toxic radical initiators. Chitosan, starch, inulin and alginate are examples of polysaccharides widely used to obtain these kind of systems, while some gelatin-antioxidant materials will also be presented as representative examples of protein-based conjugates. The advantages to having these systems consist of their high stability, biocompatibility and good biological properties. All these characteristics make them suitable systems for several pharmaceutical and food applications, such as delivery devices of drugs, as preservatives and for food packaging.