本文關(guān)鍵詞： 羧甲基絲素 醚化 絲蛋白酸鈣 透析 表面活性性能　出處：《廣西工學(xué)院》2012年碩士論文　論文類型：學(xué)位論文

【摘要】：本文以廢繭、廢絲（家蠶）為原料，利用醚化、鹽溶兩種不同的手段，在溶解絲素蛋白的基礎(chǔ)上研究了其表面活性性能。一方面通過絲素蛋白與一氯乙酸的醚化反應(yīng)，使絲素單元上的活性羥基（-OH）被鈉羧甲基（-CH2COONa）取代，從而合成可溶性的羧甲基絲素，并對其乳化性、乳化穩(wěn)定性、起泡性、泡沫穩(wěn)定性、表面張力、HLB值等表面活性性能進行了測定，制備出了新型的羧甲基絲素蛋白表面活性劑。另一方面通過鹽溶、脫鹽等手段，將絲素溶于氯化鈣溶液中，對其表面活性性能做了測定，制備出了絲蛋白酸鈣。有效利用了蠶絲、廢絲，使得蠶絲蛋白表面活性性能研究成為可能。 本論文主要做了以下幾方面的研究工作，研究內(nèi)容和結(jié)果如下： 1、利用制備羧甲基纖維素的方法建立了羧甲基絲素的制備工藝。廢繭、廢絲在除雜精選后，投入0.5%的Na2CO3溶液中煮沸，置烘箱內(nèi)烘干。然后與乙醇水溶液混合進行堿化反應(yīng)，接著與一氯乙酸進行醚化反應(yīng)，用乙醇水溶液洗滌得到的粗產(chǎn)品。將最后產(chǎn)品干燥4h，可得到絲素蛋白醚，即羧甲基絲素蛋白。研究了影響羧甲基絲素醚化工藝的六個因素，并選取對反應(yīng)影響較為顯著的四個因素做了正交試驗，通過單因素實驗和正交實驗確定了制備羧甲基絲素的最佳工藝條件：NaOH用量為7.2g，投料比為2.2，，堿化時間為90min，醚化時間為90min，堿化溫度為25℃，醚化溫度為70℃。 2、研究了羧甲基絲素的表面活性性能。羧甲基絲素的表面張力（γCMC）為51.37mN/m，臨界膠束濃度（CMC）為1.25g/L；羧甲基絲素的HLB值為10，具有較好的親水性。與羧甲基纖維素和酪蛋白酸鈉相比，羧甲基絲素蛋白在增稠性、降低表面張力、起泡性、乳化性等性能方面較差，不能完全取代他們成為新的綠色環(huán)保產(chǎn)品。還需在性能方面盡可能的加以完善。 3、建立了新的水溶性絲素蛋白的制備工藝。廢蠶絲除雜后，投入0.5%的Na2CO3溶液中煮沸，置烘箱內(nèi)烘干。將精練絲加入到沸騰的l00mL濃度分別在30%-50%（W/W）的CaCl2溶液中，控制氯化鈣的溶解時間。將制得的絲蛋白酸鈣溶液用透析袋流水透析30h，利用微量凱氏定氮法檢測溶液中蛋白質(zhì)的含量，利用EDTA檢測鈣離子的殘留量。脫鹽后的絲素蛋白溶液冷凍干燥后制得絲蛋白酸鈣。SDS-PAGE凝膠電泳圖表明，它是由多組分構(gòu)成的，在較寬范圍內(nèi)呈連續(xù)分布。隨著鹽溶時間的延長，絲素蛋白分子量逐漸減小。但其分子量隨鹽溶時間增長變化的趨勢不是特別明顯。透析時間在30h時透析完全。絲蛋白酸鈣溶液中的蛋白質(zhì)含量基本上在3.5%之間，沒有太大的變化。 4、研究了絲蛋白酸鈣的表面活性性能。絲蛋白酸鈣乳化性能良好，乳化穩(wěn)定性很高；絲蛋白酸鈣溶液具有一定的起泡能力，起泡穩(wěn)定性比較穩(wěn)定；絲蛋白酸鈣HLB值為10，具有較好親水性；臨界膠束濃度為1.25g/L，此時表面張力為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

本文編號：1495914