魔芋葡甘聚糖/凹凸棒土复合膜的制备与表征

Preparation and characterization of konjac glucomannan/attapulgite nanocomposites

采用天然纳米粘土——凹凸棒土(AT)对魔芋葡甘聚糖(KGM)进行共混改性,并通过流延成膜的方法制备了KGM/AT纳米复合材料,采用X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)对复合材料的结构和形貌进行表征;利用热重分析(TG)、力学性能测试、溶胀性测试分别研究了复合材料的热稳定性、机械性能以及耐水性能。结果表明,AT与KGM之间可以通过氢键产生较强的相互作用,AT在一定程度上可以促进KGM结晶,适量的AT在KGM基体中可以均匀分散,而过量的AT则易发生团聚,在基体中无规分布。复合材料的起始分解温度和最快分解温度明显提高,材料的热稳定性增强。此外,随着AT的加入,复合材料的力学性能和耐水性能也得到了一定程度的改善。

A natural nano-clay, attapulgite （AT）, was introduced for the modification of konjac glucomannan （KGM） by solution blending, and KGM/AT nanocomposites were prepared by casting the blend aqueous solutions. The structure and morphology of KGM/AT blend films were characterized by using X-ray diffraction （XRD）, FT-infrared（FT-IR）, scanning electron microseopy（SEM）. Besides, the thermal stability, mechanical properties as well as water resistance of the composites were investigated by thermogravimetric analysis（TG）, measurements of mechanical properties, and swelling test, respectively. The results show that strong interactions between KGM and AT can be generated through hydrogen bond formation. Besides, the crystallinity of KGM was slightly increased with the addition of AT to a certain degree. It was also found that the appropriate amount of AT nano-rods could be dispersed uniformly with single crystal state in the matrix of KGM while excessive AT nano-rods were easily to aggregate, inducing an irregular distribution in the matrix. In addition, the thermal stability of KGM/AT composites was improved based on the increase of initial temperature of thermal decomposition and the temperature of maximum thermo-gracimetric rate. Meanwhile, a certain improvement of the mechanical properties and water resistance of the KGM films were also observed by addition of AT nanoclay.