Upon production of refined carrageenan, seaweed is extracted using alkali, commonly sodium hydroxide, which cause chemical structure changes and increment of gel strength in the carrageenan. Kappa carrageenan undergoes polymerization process in form of gelation when it is cooled to between 40–60 degree C after mixing in hot solution, depending on the cations present. Gelation of carrageenan will occur when a single helix of carrageenan molecule comes near a second identical single helix of carrageenan, thus forming a double helix structure. Viscosity and shear stress value are different in both types of carrageenan due to chemical structure changes and increment of gel strength. The chemical structure of kappa carrageenan can be determined by infrared spectroscopy characteristic. The presence of sulphate group in the carrageenan structure causes the activation energy of carrageenan biocomposite to reduce. The crystallinity structure shows that the carrageenan has a short chain structure and disorderly long chain structure.