中文摘要：

海藻酸钠作为一种天然高分子物质广泛应用于各领域,它的研究和开发对人类生存环境的可持续发展具有重要意义。系统回顾了近年来国内外对海藻酸钠提取工艺的相关研究,主要包括酸凝-酸化法、钙凝-酸化法、钙凝-离子交换法、酶解法和超滤法,简述了温度、pH值等因素对提取率的影响,并对比分析了各提取工艺的优势以及存在的问题。在此基础上,综述了海藻酸钠结构中羟基以及羧基的功能化改性及其改性化合物的潜在应用,包括氧化、磺化、共聚、酯化等新进展。最后,展望了海藻酸钠提取工艺的发展方向以及改性的发展前景。

英文摘要：

Sodium alginate as a natural polymer has been widely used in various research fields. This paper reviewed systematically recent advances in several extraction technologies in sodium alginate, mainly including acid coagulation- acidification, calcium coagulation-acidification, calcium coagulation-ion exchange, enzymolysis, ultrafihration. The advantages and shortcomings of these techniques were comparatively analyzed. On this basis, the functionalization of hydroxyl group and carboxyl group in sodium alginate were summarized, and the potential application of sodium alginate derivative was also discussed. Furthermore, we present the suggestions and outlooks concerning on the further development directions towards key researches based on the existing problems in the current extraction and functionalization of sodium alginate.