十六烷基羧甲基淀粉醚的挤压法制备及其性质的研究

发布时间：2018-08-15 18:11

【摘要】：以羧甲基淀粉为原料,溴代十六烷为醚化剂,NaOH为催化剂,利用双螺杆挤压机在干法挤压条件下制备了一种高碳疏水基团的十六烷基羧甲基淀粉醚。探讨了醚化剂用量、螺杆转速、机筒温度、物料水分及碱用量对产品乳化性的影响,利用紫外分光光度计、红外光谱分析仪、粒度仪等对不同取代度(0、0.025 6、0.049 5、0.058 0、0.0701)的十六烷基羧甲基淀粉醚的结构和表面活性、乳液粒径等进行了表征比较。红外光谱图在2 960~2 850 cm~(-1)处产生了吸收峰,-OH的伸缩振动变得弱而平缓,这是因为淀粉中羟基基团进一步被取代所导致,说明溴代十六烷的长碳链已接入淀粉分子;与原淀粉相比,产物的表面张力减小,且随着产物溶液质量分数的增大表面活性越大;随着醚化取代度的增加,乳状液的平均粒度逐渐减小,从粒径分布可以证明羧甲基淀粉疏水化后乳化性明显得以改善;当淀粉接入长碳链疏水基团后,十六烷基羧甲基淀粉醚的水溶性降低。
[Abstract]:A high carbon hydrophobic cetyl carboxymethyl starch ether was prepared by twin-screw extruder with carboxymethyl starch as raw material, cetyl bromide as etherifying agent and NaOH as catalyst. The effects of etherifying agent dosage, screw speed, barrel temperature, water content and alkali dosage on the emulsifying property of the product were discussed. The structure and surface activity of the sixteen alkyl carboxymethyl starch ether with different degree of substitution (0,0.025 6,0.049 5,0.058 0,0.0701) were characterized by ultraviolet spectrophotometer, infrared spectrum analyzer and particle size analyzer. The absorption peak of the infrared spectrum was obtained at 2 960~2 850 cm~ (-1), and the stretching vibration of -OH became weak and gentle. This is due to the further substitution of hydroxyl groups in starch, indicating that the long carbon chain of cetyl bromide has been incorporated into starch molecules; the surface tension of the product decreases compared with the original starch, and the surface activity increases with the increase of the mass fraction of the product solution; with the increase of etherification degree of substitution, the average particle size of the emulsion decreases gradually from the granule. Diameter distribution showed that the emulsification of carboxymethyl starch was improved obviously after hydrophobic treatment, and the water solubility of cetylcarboxymethyl starch ether decreased when the starch was added to the hydrophobic group of long carbon chain.
【作者单位】：沈阳师范大学粮食学院;沈阳师范大学化学与生命科学学院;
【基金】：国家星火计划(2015GA650007) 辽宁“百千万人才工程”人选项目(2013921038)
【分类号】：TS231

【相似文献】