Rajisha K R, Maria H J, Pothan L A, Ahmad Zakiah, Thomas S
Department of Chemistry, CMS College, Kottayam, Kerala, India.
School of Chemical Sciences, Mahatma Gandhi University, Priyadarsini Hills, Kottayam, Kerala, India.
Int J Biol Macromol. 2014 Jun;67:147-53. doi: 10.1016/j.ijbiomac.2014.03.013. Epub 2014 Mar 19.
Potato starch nanocrystals were found to serve as an effective reinforcing agent for natural rubber (NR). Starch nanocrystals were obtained by the sulfuric acid hydrolysis of potato starch granules. After mixing the latex and the starch nanocrystals, the resulting aqueous suspension was cast into film by solvent evaporation method. The composite samples were successfully prepared by varying filler loadings, using a colloidal suspension of starch nanocrystals and NR latex. The morphology of the nanocomposite prepared was analyzed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). FESEM analysis revealed the size and shape of the crystal and their homogeneous dispersion in the composites. The crystallinity of the nanocomposites was studied using XRD analysis which indicated an overall increase in crystallinity with filler content. The mechanical properties of the nanocomposites such as stress-strain behavior, tensile strength, tensile modulus and elongation at break were measured according to ASTM standards. The tensile strength and modulus of the composites were found to improve tremendously with increasing nanocrystal content. This dramatic increase observed can be attributed to the formation of starch nanocrystal network. This network immobilizes the polymer chains leading to an increase in the modulus and other mechanical properties.
研究发现，马铃薯淀粉纳米晶体可作为天然橡胶（NR）的有效增强剂。淀粉纳米晶体是通过对马铃薯淀粉颗粒进行硫酸水解而获得的。将胶乳与淀粉纳米晶体混合后，通过溶剂蒸发法将所得水悬浮液浇铸成膜。使用淀粉纳米晶体和NR胶乳的胶体悬浮液，通过改变填料含量成功制备了复合样品。通过场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）对制备的纳米复合材料的形态进行了分析。FESEM分析揭示了晶体的尺寸和形状及其在复合材料中的均匀分散。使用XRD分析研究了纳米复合材料的结晶度，结果表明结晶度随填料含量总体增加。根据ASTM标准测量了纳米复合材料的力学性能，如应力-应变行为、拉伸强度、拉伸模量和断裂伸长率。发现复合材料的拉伸强度和模量随着纳米晶体含量的增加而大幅提高。观察到的这种显著增加可归因于淀粉纳米晶体网络的形成。该网络固定了聚合物链，导致模量和其他力学性能增加。
