硫酸铝改性海藻酸钙纤维的结构与性能

Structure and properties of aluminum sulfate modified calcium alginate fibers

通过浸渍法采用硫酸铝溶液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.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Al3+与纤维分子结构中的Na+发生离子交换并形成新的配位结构,而且改性后纤维的结晶结构转变,结晶度显著提高.改性后纤维的断裂强度为2.94 cN/dtex,比未改性纤维提高11%;吸湿性下降,耐盐性提高,随着NaCl溶液质量浓度和温度的提高,改性纤维的强度下降.改性后纤维经直接染料染色后的K/S值为4.5以上,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 modified by immersing into aluminum sulfate aqueous solu- tion in order to improve salt resistance and dyeing properties of CAF. The FTIR and XRD of CAF before and af- ter modification indicated that the carboxyl groups react with hydroxyl groups involved in macromolecular struc- ture of calcium alginates fibers to form ester compounds. Meanwhile, aluminum ions in the solution exchange with sodium ions contained in macromolecular structure of calcium alginate fibers to form new coordination structure. The crystal structure of modified calcium alginate fiber （MCAF） was changed and the crystallinity in- creased. The breaking strength of MCAF was 2.94 cN/dtex, which was 11% higher than that of CAF. The wa- ter absorbability of MCAF decreased, and the salt resistance increased. The breaking strength of MCAF de- creased with the increase of NaCI concentration and temperature. The K/S value of direct dyed MCAF was above grade 4.5, which was 37.5 times higher than that of dyed CAF. Moreover, the color fastness to wash- ing of dyed MCAF was above grade 4.