采用硫酸铝溶液浸渍处理对海藻酸钙纤维进行改性,以提高纤维的耐盐性,改善其染色性能。结果表明,纤维的最佳改性工艺条件为硫酸铝浓度159/6,溶液温度45℃,处理时间40min,此时纤维的断裂强度比未改性纤维提高了11%。改性前后纤维的FT—IR和XRD表明,纤维分子结构中的羧基和羟基发生了酯化反应,同时A1抖与纤维分子结构中的Na+发生离子交换,形成新的配位结构,而且改性后纤维的结晶结构转变,结晶度显著提高。改性后纤维的吸湿性下降,但经直接染料染色后的K/S值为4.5,是未改性纤维的37.5倍,且耐水洗牢度达到4级以上。
Calcium alginate fibers (CAF) were immersed into aluminum sulfate aqueous solution in order to im- prove salt resistance and dyeing properties of CAF. The optimum conditions for modification of CAF were as following: concentration of aluminum sulfate was 15wt%, reaction temperature was 45℃ and reaction time was 40rain. Under these conditions, the breaking strength of modified calcium alginate fiber (MCAF) was 2.94cN/ dtex which was 11% higher than that of CAF. The structure of both CAF and MCAF was characterized by FT- IR and XRD. During modification process, carboxyl groups react with hydroxyl groups involved in calcium algi- nares fibers' macromolecular structure to form ester compounds. Meanwhile, aluminum ions in the solution exchange with sodium ions contained in calcium alginate fibers' macromolecular structure to form a three dimen- sional network configuration with alginate macromolecular which was different from the "egg-box" structure of the compound containing calcium ions and alginate macromolecular. The results of XRD show that crystal structure of MCAF was changed and crystallinity of MCAF has increased with the comparision of unmodified calcium alginate fibers. However, crystallinity of MCAF slightly decreases with the increase of temperature and concen- tration of aluminum sulfate aqueous solution. The water absorbability of MCAF decreases compare with CAF, especially for solution A that was used to imitate the wound exudates. The water absorbability of CAF was 13.1 in solution A, but that of MCAF declines to 1.28. However, the water absorbability of MCAF was still much better than that of cotton fibers. The K/S value of dyed MCAF was about 4.5, which was 37.5 times higher than that of dyed CAF. Moreover, the color fastness to washing of dyed MCAF was above grade 4.