Chemical Modification of Marine Polysaccharide (Alginate) By Free-Radical Graft Copolymerization― a Short Review

Because of considerable interest in the preparation of biodegradable materials based on natural polymers, many techniques have been used to modify the physical and chemical properties of natural polymers. Due to the presence of various functional groups on molecular chains, polysaccharides could be readily modified chemically to form polymer hybrid of good composition and functional properties. There have been a number of studies reported for chemical attachments of synthetics polymers. However, grafting of vinyl monomers onto polysaccharides backbone via radical polymerization is often used technique. Alginic acid or alginate is polyuronides, i.e., polysaccharides in which the molecules are built up of uronic acid residues which are obtained from seaweed species of brown algae. Alginate has broad applications in various fields such as pharmaceutical, biomedical, agriculture, and environmental. The present review compiled the studies on the chemical modification of alginate via freeradical graft copolymerization, particularly by generating the free radicals using thermal initiator or electron transfer reaction (redox system) and the potential applications of the grafted copolymers.