改性木薯淀粉胶黏剂的制备及性能研究

Preparation and Properties of Modified Cassava Starch Adhesive

目的探究不同含量的氧化剂、糊化剂以及交联剂对木薯淀粉性能的影响。方法通过红外、流变学表征方法系统研究了糊化剂(NaOH)和氧化剂(NaClO)用量对淀粉胶黏剂性能的影响。结果当加入16%(相于干淀粉质量而言)的NaClO作为氧化剂时,淀粉胶黏剂的初黏力和黏度都达到最佳。当加入10%(相对干淀粉质量而言)的NaOH作为糊化剂时,淀粉在室温下就能发生糊化,形成黄色透明状胶黏剂,此时,胶黏剂有明显的触变性。结论NaClO的加入可以很好地改变淀粉胶黏剂的流动性,但过量的NaClO会使胶黏剂黏度过小,并致耐水性和黏结性不足。适量的NaOH加入可以使淀粉的黏度增加,但过量的NaOH会减弱重新缠结的淀粉高分子链间的作用力,导致黏度下降。硼砂的加入能与淀粉分子形成络合物,使淀粉胶黏剂的黏度有明显提升。

The work aims to study the effects of different contents of oxidants,gelatinizers and crosslinkers on the properties of cassava starch.The effect of pasting agent(NaOH)and oxidant(NaClO)on starch pasting and their dosage on starch adhesive properties were systematically investigated by infrared and rheological characterization methods.When 16%NaClO(relative to dry starch)was added as an oxidant,the initial adhesion and viscosity of starch adhesive reached the best.When 10%NaOH(relative to dry starch)was added as a gelatinizer,starch could gelatinize at room temperature to form yellow transparent adhesive,and the adhesive had obvious thixotropy.The addition of NaClO can change the fluidity of the starch adhesive well,but excessive NaClO will make the viscosity of the adhesive too low and lead to insufficient water resistance and adhesion.Adding proper amount of NaOH can increase the viscosity of starch.However,excessive NaOH will weaken the force between the re-entangled starch polymer chains,resulting in a decrease in viscosity.The addition of borax can form a complex with starch molecule,so the viscosity of starch adhesive can be improved obviously.