交联-羧甲基复合变性淀粉合成及结构表征

Synthesis and Structural Characterization of Cross-linked Carboxymethylated Composite-modified Starch

以环氧氯丙烷为交联剂,一氯乙酸为醚化剂,合成交联-羧甲基复合变性淀粉,考察交联、羧甲基化对淀粉表观及内部结构的作用。通过可见光吸收光谱,差示扫描量热、扫描电镜、X衍射、红外光谱对原淀粉、交联淀粉、羧甲基淀粉、复合变性淀粉进行结构与性质的表征及分析。结果显示:交联反应主要发生在淀粉颗粒表面的无定形区,羧甲基化反应发生在淀粉颗粒的无定形区及结晶区,交联-羧甲基复合变性淀粉兼有单一变性淀粉的性能。

Cross-linked carboxymethylated composite-modified starch was prepared by using wheat starch as material, monochloroacetic acid and epichlorohydrin as carboxymethylated agent and cross-linking agent respectively. The effect of cross-linking and carboxymethylating on the apparent and inside structure of starch was investigated. Original starch, cross-linked starch, carboxylmethylated starch, eross-linked carboxymethylated composite-modified starch were characterized through the visible light absorption, different scanning calorimeter, scanning microscopy, X-ray diffraction, infrared spectrum. The result showed： cross-linking mainly took place in amorphous district of surface of starch particle, carboxylmethylating occurred in amorphous district and crystallization district of starch particle to destroy the starch particle structure. Cross-linked carboxymethylated composite-modified starch was accompanied with properties of single modified starch.