Physicochemical properties of sodium alginate from brown algae Sargassum aquifolium and Sargassum cinereum

Abstract Synthesis and characterization of sodium alginate from Sargassum aquifolium dan cinereum have been successfully performed. S. were collected the Dompu Islands, West Nusa Tenggara, Indonesia. Extraction was performed by acid pathway, due to cell disruption addition Na 2 CO 3 for extraction. The HCl convert into alginate, then transformed using NaOH. NaOCl IPA used purification. Physicochemical properties characterized SEM-EDS, FTIR, TG/DTG. morphological structure synthetic shows layer fiber fibrils. Sodium contained C, O, Na, Cl elements. FTIR spectrum indicated presence functional groups at following wavelengths: OH 3343 cm −1 , CH 2915 double bonds 1614 fingerprint uronic acid, which functioned as group stretched 935 . sample a three-step thermal degradation pattern. first step starting 41.7 °C associated with dehydration followed 206.4 241 decomposition. TGA/DTG results showed reduction in stability 250–300 °C. It is suitable modification application.