玉米淀粉制备羧甲基淀粉的研究

Study on Preparation of Carboxymethyl Starch from Corn Starch

玉米淀粉作为一种重要的生物质资源,在食品、纺织、造纸、医药等领域有着广泛的应用。然而,传统玉米淀粉的溶解性和冻融稳定性等性能的限制,严重影响了其在工业上的应用。因此,采用异丙醇-水混合溶剂法制备羧甲基淀粉,通过调控淀粉与NaOH物质的量比、反应介质体积、异丙醇质量分数、氯乙酸钠质量和醚化时间等参数,成功制备出了取代度为0.7的高取代度羧甲基淀粉,其溶胀度达到了36.56 g.g^(-1)。该方法通过加入水,使得NaOH更好地与淀粉表面接触,同时水的存在促进了氯乙酸钠更好地进入淀粉分子内部参与反应,从而大大提高了反应效率。利用红外光谱、XRD衍射图谱、SEM等表征手段证明了羧甲基化的成功,为未来大规模生产高取代度羧甲基淀粉提供了一种简单可行的方法。

Corn starch,as an important biomass resource,has extensive applications in fields such as food,textiles,papermaking and pharmaceuticals.However,the traditional corn starch suffers from limitations in solubility and freezethaw stability,significantly impacting its industrial applications.Hence,the isopropanol-water mixed solvent method was used to prepare carboxymethyl starch,successfully achieving a high degree of substitution carboxymethyl starch with a substitution degree of 0.7 and a swelling degree of 36.56 g.g-1 by controlling parameters including molar ratio of starch to NaOH,reaction medium volume,isopropanol mass fraction,sodium chloroacetate dosage,and etherification time.The addition of water in this method facilitated better contact between NaOH and starch surface while enabling sodium chloroacetate to penetrate starch molecules more effectively,thereby greatly enhancing reaction efficiency.The successful carboxymethylation was confirmed through characterization techniques including infrared spectroscopy,XRD diffraction patterns,and SEM,providing a simple and feasible method for large-scale production of high degree of substitution carboxymethyl starch in the future.