Grafting modification is a common method for improving the specific properties of polysaccharides. Herein, we synthesised sodium alginate-g-poly (acrylic acid) (NaAlg-g-PAA) as a novel printing thickener via catalysis of horseradish peroxidase and hydrogen peroxide in the presence of acetylacetone. The synthesised products were characterised by Fourier Transform–infrared spectroscopy and polar nuclear magnetic resonance spectroscopy, which confirmed that the PAA was successfully grafted onto the hydroxyl groups at carbon atoms (C2) of sodium alginate. The optimal grafting percentage and grafting efficiency reached 51% and 96%, respectively. Compared with native sodium alginate, the grafted copolymer NaAlg-g-PAA exhibited better thermal stability, rheological and printing properties. This work provides an efficient and promising approach for modifying polysaccharides like alginates and could be used as an alternative to conventional chemical modification.

中文翻译：

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酶法合成海藻酸钠-g-聚丙烯酸接枝共聚物作为新型印刷增稠剂

接枝修饰是提高多糖特定性能的常用方法。在此，我们在乙酰丙酮存在下通过辣根过氧化物酶和过氧化氢的催化合成了海藻酸钠-g-聚（丙烯酸）（NaAlg-g-PAA）作为新型印刷增稠剂。合成的产物通过傅里叶变换红外光谱和极性核磁共振光谱进行了表征，证实了 PAA 成功接枝到海藻酸钠碳原子 (C2) 的羟基上。最佳接枝率和接枝效率分别达到51%和96%。与天然海藻酸钠相比，接枝共聚物NaAlg-g-PAA表现出更好的热稳定性、流变性和印刷性能。