两种新型丝素衍生物的研制与性能研究

发布时间：2018-02-08 16:53

  本文关键词： 羧甲基丝素 醚化 丝蛋白酸钙 透析 表面活性性能　出处：《广西工学院》2012年硕士论文　论文类型：学位论文

【摘要】：本文以废茧、废丝（家蚕）为原料，利用醚化、盐溶两种不同的手段，在溶解丝素蛋白的基础上研究了其表面活性性能。一方面通过丝素蛋白与一氯乙酸的醚化反应，使丝素单元上的活性羟基（-OH）被钠羧甲基（-CH2COONa）取代，从而合成可溶性的羧甲基丝素，并对其乳化性、乳化稳定性、起泡性、泡沫稳定性、表面张力、HLB值等表面活性性能进行了测定，制备出了新型的羧甲基丝素蛋白表面活性剂。另一方面通过盐溶、脱盐等手段，将丝素溶于氯化钙溶液中，对其表面活性性能做了测定，制备出了丝蛋白酸钙。有效利用了蚕丝、废丝，使得蚕丝蛋白表面活性性能研究成为可能。 本论文主要做了以下几方面的研究工作，研究内容和结果如下： 1、利用制备羧甲基纤维素的方法建立了羧甲基丝素的制备工艺。废茧、废丝在除杂精选后，投入0.5%的Na2CO3溶液中煮沸，置烘箱内烘干。然后与乙醇水溶液混合进行碱化反应，接着与一氯乙酸进行醚化反应，用乙醇水溶液洗涤得到的粗产品。将最后产品干燥4h，可得到丝素蛋白醚，即羧甲基丝素蛋白。研究了影响羧甲基丝素醚化工艺的六个因素，并选取对反应影响较为显著的四个因素做了正交试验，通过单因素实验和正交实验确定了制备羧甲基丝素的最佳工艺条件：NaOH用量为7.2g，投料比为2.2，，碱化时间为90min，醚化时间为90min，碱化温度为25℃，醚化温度为70℃。 2、研究了羧甲基丝素的表面活性性能。羧甲基丝素的表面张力（γCMC）为51.37mN/m，临界胶束浓度（CMC）为1.25g/L；羧甲基丝素的HLB值为10，具有较好的亲水性。与羧甲基纤维素和酪蛋白酸钠相比，羧甲基丝素蛋白在增稠性、降低表面张力、起泡性、乳化性等性能方面较差，不能完全取代他们成为新的绿色环保产品。还需在性能方面尽可能的加以完善。 3、建立了新的水溶性丝素蛋白的制备工艺。废蚕丝除杂后，投入0.5%的Na2CO3溶液中煮沸，置烘箱内烘干。将精练丝加入到沸腾的l00mL浓度分别在30%-50%（W/W）的CaCl2溶液中，控制氯化钙的溶解时间。将制得的丝蛋白酸钙溶液用透析袋流水透析30h，利用微量凯氏定氮法检测溶液中蛋白质的含量，利用EDTA检测钙离子的残留量。脱盐后的丝素蛋白溶液冷冻干燥后制得丝蛋白酸钙。SDS-PAGE凝胶电泳图表明，它是由多组分构成的，在较宽范围内呈连续分布。随着盐溶时间的延长，丝素蛋白分子量逐渐减小。但其分子量随盐溶时间增长变化的趋势不是特别明显。透析时间在30h时透析完全。丝蛋白酸钙溶液中的蛋白质含量基本上在3.5%之间，没有太大的变化。 4、研究了丝蛋白酸钙的表面活性性能。丝蛋白酸钙乳化性能良好，乳化稳定性很高；丝蛋白酸钙溶液具有一定的起泡能力，起泡稳定性比较稳定；丝蛋白酸钙HLB值为10，具有较好亲水性；临界胶束浓度为1.25g/L，此时表面张力为61.37mN/m。
[Abstract]:In this paper, using waste cocoon, waste silk (silkworm) as raw material, using etherification and salinization, the surface activity of silk fibroin was studied on the basis of dissolving silk fibroin, on the one hand, the etherification of silk fibroin with monochloroacetic acid was carried out through the etherification of silk fibroin and monochloroacetic acid. The active hydroxyl group on silk fibroin unit was replaced by sodium carboxymethyl-CH2COONa. soluble carboxymethyl fibroin was synthesized and its surface active properties, such as emulsification, emulsification stability, foaming stability, foam stability, surface tension and HLB value, were determined. A new carboxymethyl silk fibroin surfactant was prepared. On the other hand, silk fibroin was dissolved in calcium chloride solution by salinization and desalination, and its surface activity was determined. Calcium monophosphate was prepared, and silk and waste silk were effectively utilized, which made it possible to study the surface activity of silk protein. The main contents and results of this thesis are as follows:. 1. The preparation process of carboxymethyl fibroin was established by using the method of preparing carboxymethyl cellulose. After removing impurities, the waste silk was boiled in 0.5% Na2CO3 solution and dried in oven. Then mixed with ethanol aqueous solution, the waste silk was alkalized. After etherification with monochloroacetic acid, the crude product was washed with ethanol aqueous solution. After drying the final product for 4 h, silk fibroin ether, that is, carboxymethyl fibroin protein, was obtained. Six factors affecting the etherification process of carboxymethyl fibroin were studied. The orthogonal experiments were carried out by selecting four factors that had a significant effect on the reaction. The optimum conditions of preparing carboxymethyl fibroin were determined by single factor experiment and orthogonal experiment. The dosage of: NaOH was 7.2 g, the feed ratio was 2.2, the alkali time was 90 min, the etherification time was 90 min, the alkalization temperature was 25 鈩

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