Establishment of Stabilization Technology of Extruded Starch Fibers

答：通过直径为0.2 mm的圆形或矩形加压喷嘴，以60℃的速度将约10%的淀粉水溶液挤出到40%的硫酸铵溶液中，可制得淀粉纤维。在各种淀粉样品中，玉米淀粉制备淀粉纤维的效果最好，这可能是因为玉米淀粉中直链淀粉和支链淀粉的质量比合适。为了提高得到的淀粉纤维在高温或弱碱性条件下的纤维形态稳定性，在淀粉纤维中加入了几种交联剂。然而，在目前考察的各种条件下，都不能获得足够的形状稳定性。另一方面，在淀粉溶液中加入碳酸钙或氧化钛进行挤压时，得到的淀粉纤维对热和弱碱性条件具有较高的形状稳定性。此外，这些含有无机填料的淀粉纤维还可以保持手抄纸的不透明度。D.将其黄原酸酯溶液纺丝作为两种多糖的共溶剂，制备了纤维素-淀粉杂化纤维。由于纤维素组分主要存在于这些杂化纤维的表面，因此由于淀粉组分的特殊性质不会出现在杂化纤维上。因此，控制淀粉和纤维素组分在杂化纤维横截面上的分布是提高纤维素-淀粉杂化纤维性能的必要手段。

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.