이온 가교에 의한 수용성 알긴산나트륨의 경화와 염 수용액에 의한 이의 재용해에 관한 연구

Abstract

In this work, the insolubilization of water-soluble sodium alginate, which is a representativebiomass natural polymer, was investigated for various purposes, including coatingson paper cups. It was observed that sodium alginate could be insolubilized well incalcium chloride by formation of ionic crosslinks through replacement of Na+ ions withCa2+ ions on a block of L-guluronic acid of alginate to form calcium alginate. Water-insolubilizationof alginate is a critical prerequisite for the coatings on cups to retain water. However,the calcium alginate coating needs to undergo re-dissolution in water to enablerecycling of the paper cups after use. It was observed that calcium alginate could be easilyre-dissolved in a specific aqueous salt solution containing disodium phosphate (Na2HPO4). The re-dissolution of calcium alginate was confirmed by scanning electron microscopy andenergy-dispersive X-ray spectroscopy (EDS). The process developed in this study isexpected to be used for various eco-friendly applications without the need to use organicsolvents.