双醛淀粉及其交联效率的研究

【作者】 王保金；

【导师】 周家华；

【作者基本信息】 广东工业大学 ， 化学工艺， 2004， 硕士

【摘要】 双醛淀粉是一种多功能、高反应活性的羰基化合物，与低分子量的交联剂，如戊二醛和乙二醛相比较，具有毒性小、可再生性和生物可降解性，在各种工业中具有广阔的应用潜力。在国内，双醛淀粉几乎没有生产和应用；虽然双醛淀粉在一些国家已经商业化，但是至今也没有大规模的应用。一方面，是由于双醛淀粉的生产成本高；另一方面，是由于双醛淀粉的交联效率低。我国淀粉资源极为丰富，同时，也很没有关于双醛淀粉低交联效率机理的文献报道。为此，我们深入研究双醛淀粉的制备和性质，并探讨影响双醛淀粉交联效率的因素，为双醛淀粉的推广应用提供理论指导： 1．影响双醛淀粉的醛基含量的因素有反应时间、反应温度、高碘酸钠浓度、反应pH值及高碘酸钠与淀粉的摩尔比。根据单因素实验结果，固定高碘酸钠与淀粉的摩尔比确定为1.1∶1不变，对其余的四因素进行均匀优化实验。根据均匀实验结果，最优化工艺条件为反应时间为3.47小时，反应温度为36.46℃，高碘酸钠浓度为0.63mol／L，反应pH值为1.83，高碘酸钠与淀粉的摩尔比为1.1∶1。 2．将已知醛基含量的双醛淀粉水悬浮液在不同pH值条件进行各种加热处理。酸产物（（COOH）_T）量用NaOH连续滴定测定。通过滴加羟胺，测定肟的生成数量，来计算具有反应活性醛基(（CHO）_T^oxime)的含量。具有反应活性的醛基含量要比真实的醛基含量低。 3．双醛淀粉稳定性及流变性的研究表明表明：醛基含量高的双醛淀粉颗粒不易膨胀，绝对粘度值低；双醛淀粉颗粒的强度由内部交联的数量所决定，与醛基含量成一定的比例；在碱性条件下，双醛容易膨胀。 4．双醛淀粉与壳聚糖相互作用的研究表明：影响双醛淀粉交联效率的因素主要有两个：一是双醛淀粉中醛基的含量；二是双醛淀粉的分子量。 5．双醛淀粉与明胶相互作用的研究表明：乙二醛、戊二醛和双醛淀粉的交联效率：戊二醛＞双醛淀粉＞乙二醛。更多还原

【Abstract】 Dialdehyde starch is a multifunctional, highly reactive carbonyl compound. It is generally accepted that dialdehyde starch has its very low toxicity, renewability and degradability compared with low molecular weight cross-linkers such as glyoxal and glutaraldehyde. Dialdehyde starch has found broad potential applications in various industries. Dialdehyde starch is scarcely produced and applied in China. Though its production has been commercialized in some countries, as yet, dialdehyde starch has not found any important application on large scale. On the one hand, the cost of dialdehyde starch is high. On the other hand, dialdehyde starch has low cross-linking efficiency. Starch resources are very abundant in China and no literature is available on the mechanism of low cross-linking efficiency. So we study the preparation, properties of dialdehyde starch and investigate the factors that influence the cross-linking efficiency of dialdehyde starch and hope to find the theories to improve the applications of dialdehyde starch.1. The factors that influence the aldehyde content in dialdehyde starch included reaction time, reaction temperature, concentrations of sodium periodate, reaction PH, and the ratio of sodium periodate to starch. A four-factor homogeneous experiment was designed with fixed ratio of sodium periodate to starch at 1.1:1. It was found that the optimal conditions were reaction time 3.47 hours, reaction temperature 36.46 C, reaction concentration of sodium periodate 0.63mol/L, reaction pH 1.83.2. Dialdehyde starch of known aldehyde content were subjected to various heat treatments in aqueous suspensions at different pHvalues. Acid product was determined by continuous titration with sodium hydroxide. The amount of reactive aldehydes ((CHO) T 掳xime) was calculated by measuring the oxime formation upon addition of hydroxylamine. The amount of reactive aldehydes is lower than the actual amount of aldehydes.3. The study of the stability and Theological properties shown that the dialdehyde starch with high aldehyde content didn’t easily swell, the absolute viscosity was lower than that of dialdehyde starch with low aldehyde content and the dialdehyde starch swelled easily in alkaline medium.4. The study of interaction of dialdehyde starch and chitosan shown that two main factors influenced the cross-linking efficiency of dialdehyde starch. One was thealdehyde content. The other was the molecular weight of dialdehyde starch.5. The study of interaction of dialdehyde starch and gelatin shown that the order of the cross-linking efficiency was: glutaraldehyde > dialdehyde starch > glyoxal.更多还原