Sodium alginate (SA) solution with high quality fraction was prepared by NaOH/urea, NaOH/thiourea/urea, NaOH/thiourea and LiOH/urea at low temperature. The results showed that we got 5.5 wt% SA solution by using 5.5 wt% LiOH/20 wt% urea. The viscosity of the solution was 62.44 Pa·s, which had declined by 64% compared to that of 5 wt% SA solution (176.12 Pa·s). The difference from the traditional low temperature dissolution principle is that the urea is mainly wrapped on the SA surface by the interaction between the OH⁻ in LiOH through the ether bond (O) and the π bond in the SA instead of the -OH in the SA. Only the crystallization peak of urea appeared in the XRD spectrum. It indicated that urea was successfully wrapped on the surface of SA to form urea-LiOH-SA inclusion complex. The ²³Na NMR showed that the interaction between Na⁺ and other ions or molecules around it increased at low temperature. Breaking strength of regenerated CA was 2.44 cN/dtex, which rose by about 21.39% compared to that of CA fiber (2.01 cN/dtex). The “groove” on the surface of regenerated fiber is denser and the section is more loosely compared with those of CA fiber.

低温下用NaOH /尿素，NaOH /硫脲/尿素，NaOH /硫脲和LiOH /尿素制备出高质量的藻酸钠溶液。结果表明，通过使用5.5重量％的LiOH / 20重量％的尿素，我们得到了5.5重量％的SA溶液。溶液的粘度为62.44 Pa·s，与5 wt％的SA溶液（176.12 Pa·s）相比下降了64％。从传统的低温溶解原理的不同之处在于脲由OH之间的相互作用主要是缠绕在SA表面上^-在LiOH通过醚键（Ô）和SA中的π键，而不是SA中的-OH。在XRD谱图中仅出现尿素的结晶峰。这表明尿素被成功包裹在SA表面，形成尿素-LiOH-SA包合物。的²³的Na NMR表明：Na之间的相互作用⁺和其它离子或在其周围的分子在低温下增加。再生CA的断裂强度为2.44 cN / dtex，比CA纤维（2.01 cN / dtex）的断裂强度提高了约21.39％。与CA纤维相比，再生纤维表面的“凹槽”更致密，截面更松散。