机械活化干法制备玉米羧甲基淀粉工艺研究

以玉米淀粉为原料,氯乙酸钠为醚化剂,氢氧化钠为催化剂,采用机械活化干法制备羧甲基淀粉。以取代度（degree of substitution,DS）为评价指标,通过单因素和正交实验设计优化玉米羧甲基淀粉制备工艺。采用红外光谱（sourier transform infrared spectroscopy,FTIR）、X-射线衍射（x-ray diffraction,XRD）、扫描电镜（scanning electron microscope,SEM）对羧甲基淀粉的结构进行表征。结果表明,机械活化干法制备羧甲基淀粉最佳工艺条件:淀粉与氯乙酸钠摩尔比为1∶1、淀粉与氢氧化钠摩尔比为1∶1.25（以淀粉干基计）、球磨时间为90 min,球磨温度为60℃,球磨转速为380 r·min-1、球磨介质堆体积500 m L,在该实验条件下制备的玉米羧甲基淀粉的取代度为0.5086。FTIR、XRD、SEM进一步证实玉米淀粉发生了醚化反应。 

Research on technology of preparing carboxymethyl maize starch by mechanical activation-strengthened dry method

The carboxymethyl maize starch was prepared using maize starch as a material, monochloroacetate ( MCA) as etherifying agent and sodium hydroxide ( Na OH) as catalyst by the mechanical activation-strengthened dry method.Single factor experiments and orthogonal array design methods were used to optimize the preparation conditions of carboxymethyl maize starch based on the degree of substitute ( DS) . The structure of the carboxymethyl maize starch were characterized by using fourier transform infrared spectroscopy ( FTIR) , X-ray diffraction ( XRD) and scanning electron microscope ( SEM) . The results showed that the optimum technology conditions were as follows: the mole ratio of starch and monochloroacetate was 1 ∶ 1, the mole ratio of starch and sodium hydroxide was 1 ∶ 1.25, ball-milling time was 90 min, ball-milling temperature was 60 ℃, stiring speed 380 r·min-1, tack media 500 m L, the DS of products 0.5086.The etherification reaction of maize starch had been confirmed further by FTIR, XRD, SEM.