Establishment of Stabilization Technology of Extruded Starch Fibers

a .通过直径0.2 mm的圆形或矩形加压喷嘴，将约10%的淀粉水溶液在60℃下挤压到40%的硫酸铵溶液中，即可制备淀粉纤维。在各种淀粉样品中，玉米淀粉制备淀粉纤维的效果最好，这可能是由于玉米淀粉中直链淀粉和支链淀粉的质量比比较合适。为了提高所制淀粉纤维在热或弱碱性条件下的纤维形状稳定性，在淀粉纤维上加入了不同种类的交联剂。然而，只要迄今为止所研究的各种条件，就不能达到足够的形状稳定性。另一方面，当在淀粉溶液中加入碳酸钙或氧化钛填料进行挤压时，得到的淀粉纤维在热和弱碱性条件下具有较高的形状稳定性。此外，使用这些含有无机填料的淀粉纤维可以保持手纸的不透明度。以黄原药溶液作为两种多糖的共溶剂，纺丝制备纤维素-淀粉杂化纤维。由于纤维素成分主要存在于这些杂交纤维的表面，由于淀粉成分的特定性质不会出现在杂交纤维上。因此，控制淀粉和纤维素组分在杂交纤维横截面上的分布是改善纤维素-淀粉杂交纤维的必要条件。

A. Starch fibers can be prepared by extruding about l0% aqueous starch solutions into 40% ammonium sulfate solutions at 60℃ through a pressurized nozzle with circle or rectangular shape of 0.2 mm diameter. Among various starch samples, corn starch was the best for preparing starch fibers probably because of a suitable weight ratio between amylose and amylopectin in the corn starch.B. In order to increase stability of fibrous shape of the obtained starch fibers to thermal or weakly alkaline conditions, some kinds of cross-linking reagents were applied to the starch fibers. However, sufficient shape-stability could not be achieved as long as the various conditions examined so far.C. On the other hand, when calcium carbonate or titanium oxide filler was mixed in the starch solutions for extruding, the obtained starch fibers had higher shape-stability to thermal and weakly alkaline conditions. Furthermore, opacity of handsheets can be maintained by using these starch fibers containing the inorganic fillers.D. Cellulose-starch hybrid fibers were prepared by spinning their xanthate solutions as a co-solvent for the two polysaccharides. Because the cellulose component is predominantly present at the surfaces of these hybrid fibers, specific properties due to the starch component do not appear on the hybrid fibers. Thus, controlling distributions of starch and cellulose components in the cross-sections of hybrid fibers are necessary to improve the cellulose-starch hybrid fibers for future work.