Patil Namrata V, Netravali Anil N
Department of Fiber Science & Apparel Design, Cornell University, 37 Forest Home Dr., Ithaca, New York 14853, United States.
ACS Omega. 2019 Mar 15;4(3):5392-5401. doi: 10.1021/acsomega.9b00055. eCollection 2019 Mar 31.
This study presents the preparation and use of a "green" cross-linker derived from a waste soy flour sugar (SFS) mixture to cross-link keratin in wool fibers to increase their tensile properties. Earlier studies of keratin cross-linking involved chemicals such as glyoxal and glutaraldehyde that are toxic to humans. In addition, their effectiveness in improving tensile properties has been significantly lower than obtained in this study using modified SFS. Characterization of SFS using C NMR revealed the presence of five sugars having different molecular lengths. Oxidation of SFS using sodium periodate resulted in multiple aldehyde groups, as confirmed by H NMR and attenuated total reflection Fourier-transform infrared (ATR-FTIR). The oxidized SFS (OSFS) when used to cross-link the amine groups from the wool keratin resulted in 36 and 56% increase in the tensile strength and Young's modulus of the fibers, respectively. These significant increases in strength and Young's modulus were a result of having multiple aldehyde groups on each sugar molecule as well as different molecular lengths of sugars, which favored cross-links of multiple lengths within the cortical cell matrix of wool fibers. The cross-linking between the aldehyde groups in OSFS and amine groups in wool fibers was confirmed using ATR-FTIR and from the color change resulting from the Maillard reaction as well as decrease in moisture absorption by the fibers. Stronger wool fibers can not only increase the efficiencies of wool fiber spinning and weaving and reduce yarn and fabric defects but can also allow spinning finer yarns from the same fibers. Oxidized sugars with optimum molecular lengths can be used to cross-link other biological proteins as well, replacing the currently used toxic cross-linkers.
本研究介绍了一种由废弃大豆粉糖（SFS）混合物衍生而来的“绿色”交联剂的制备及其用于交联羊毛纤维中的角蛋白以提高其拉伸性能的情况。早期对角蛋白交联的研究涉及乙二醛和戊二醛等对人体有毒的化学物质。此外，它们在改善拉伸性能方面的效果明显低于本研究中使用改性SFS所获得的效果。使用碳核磁共振（C NMR）对SFS进行表征，发现存在五种分子长度不同的糖。用过碘酸钠氧化SFS后产生了多个醛基，氢核磁共振（H NMR）和衰减全反射傅里叶变换红外光谱（ATR-FTIR）证实了这一点。当氧化后的SFS（OSFS）用于交联羊毛角蛋白中的胺基时，纤维的拉伸强度和杨氏模量分别提高了36%和56%。强度和杨氏模量的显著提高是由于每个糖分子上有多个醛基以及糖的分子长度不同，这有利于羊毛纤维皮质细胞基质内形成多种长度的交联。通过ATR-FTIR以及美拉德反应导致的颜色变化和纤维吸湿率的降低，证实了OSFS中的醛基与羊毛纤维中的胺基之间发生了交联。更强的羊毛纤维不仅可以提高羊毛纤维纺纱和织造的效率，减少纱线和织物缺陷，还可以用相同的纤维纺出更细的纱线。具有最佳分子长度的氧化糖也可用于交联其他生物蛋白质，以取代目前使用的有毒交联剂。
