利用废弃蚕丝制备蛋白基表面活性剂的工艺技术

Preparation Technology of Protein-based Surfactant Using Waste Natural Silk

针对缫丝过程产生废弃蚕丝的资源化利用问题,研究以废弃蚕丝为原料高效制备蛋白基表面活性剂的工艺技术。首先将废弃蚕丝在碱性条件下水解获得氨基酸和多肽,以蚕丝水解产物提取率为考核指标,通过正交试验确定最佳水解工艺条件:水用量为蚕丝干质量的1 600%,NaOH用量为蚕丝干质量的18%,水解温度95℃,水解时间4 h。在此条件下,蚕丝水解产物的提取率可达86.3%。进一步将蚕丝水解产物浓缩液与油酰氯进行缩合反应,以产品的表面张力、乳化力和起泡力为考核指标,在反应温度75℃、反应体系pH值为10和反应时间为2.5 h的条件下,通过单因素试验确定反应体系中蚕丝水解产物浓缩液与油酰氯的质量比为1.8∶1时,制备的阴离子蛋白基表面活性剂产品为棕黄色半透明粘稠液体,临界胶束质量浓度(CMC)为0.3 g/L,并具有良好的表面活性。试验初步建立了利用废弃蚕丝生产阴离子蛋白基表面活性剂的基础工艺技术。

In order to address resource utilization issue of waste silk generated in the process of silk reeling,preparation technology of protein-based surfactant using waste silk was developed.Amino acids and polypeptides were obtained via hydrolyzing waste silk in alkaline aqueous solution,and hydrolysis condition of waste silk was optimized via orthogonal experiments.The optimal hydrolysis condition was as follows： to use water 16 times to the dry weight of silk,to use NaOH 0.18 times to the dry weight of silk,to hydrolyze at 95 ℃,and to hydrolyze for 4 hours,under which the extraction rate of silk hydrolysis product（amino acid polypeptides） could reach 86.3%.Furthermore,anionic protein-based surfactant was synthesized by condensation reaction between silk hydrolysate concentrate and oleoyl chloride.Using surface activity,emulsifying power and foaming power of the product as evaluation indexes,single-factor experiments demonstrated that the optimal mass ratio of silk hydrolysate concentrate to oleoyl chloride was 1.8 ∶1 while other reaction conditions were set at 75 ℃,pH 10 and 2.5 hours.The prepared protein-based anionic surfactant was a light brown translucent liquid with excellent surface activity.Its critical micelle concentration（CMC） was 0.3 g/L.The above work established a primary preparation technology for synthesizing anionic protein-based surfactant using waste silk.