Abstract
Alginic acid, also called algin or alginate, is an anionic polysaccharide distributed widely in the cell walls of brown algae, where it, through binding water, forms a viscous gum. In extracted form it absorbs water quickly; it is capable of absorbing 200-300 times its own weight in water.[1] Its colour ranges from white to yellowish-brown. It is sold in filamentous, granular or powdered forms. It is a linear copolymer with homopolymeric blocks of (1-4)-linked β-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. The monomers can appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks) or alternating M and G-residues (MG-blocks). Alginate is used extensively as an impression-making material in dentistry, prosthetics, life casting and occasionally for creating positives for small-scale casting. It is also used in the food industry, for thickening soups and jellies. In this paper, explains about the applications of alginates in different industries.