淀粉的改性及其复合材料的合成与性能研究
发布时间：2018-12-10 23:50
【摘要】：本实验选用功率500W、频率20kHz的探头式超声波反应器,以蒸馏水为介质制备了超声改性淀粉。对实验条件进行了优化,随着超声波处理时间的延长,淀粉的溶解率增加,溶液的温度逐渐升高,最佳超声处理时间为10mmin,制备改性淀粉时原淀粉乳质量分数为20%. 测定了改性淀粉的性质,改性淀粉的颗粒密度为838.64kg/m3,比原淀粉颗粒密度减小。改性淀粉糊化后透光率为55.85%,比原淀粉糊透光率增加。使用扫描电子显微镜观察,发现超声波处理并没有改变淀粉颗粒的形状,而是在光滑的颗粒表面形成了许多孔洞和凹坑。X射线衍射分析淀粉颗粒的晶体结构表明,超声波改变了淀粉颗粒的非结晶区,没有改变淀粉颗粒的结晶区。 制备了超声改性淀粉/聚乙烯醇/海藻酸钠复合微球,并优化了实验条件。改性淀粉质量分数4%,聚乙烯醇质量分数8%,海藻酸钠质量分数为4%,氯化钙的质量分数为5%时制备的复合微球的形态最好。最佳的干燥方式为先室温干燥24h,再40℃烘箱干燥24h。超声改性淀粉、聚乙烯醇、海藻酸钠分子中都含有羟基,三元复合微球的红外光谱图显示复合后在3400cm-1附近的-OH伸缩振动峰的峰宽变窄,说明游离羟基的数目变少,认为三种原料之间有氢键形成。干燥前微球的平均粒径约为3.08mmm,干燥后的复合微球的平均直径约为1.03mm。微球的扫描电镜图显示微球表面和剖面都有大量的缝隙和少量孔洞,内外贯穿,有利于水分子的进入和药物的释放。 测定了复合微球的性能。随着复合微球中改性淀粉质量分数的增加,复合微球的含水率增加。复合微球在蒸馏水中浸泡2h达到溶胀平衡,溶胀倍率为160%。复合微球在pH为7.4的PBS缓冲液中可以缓慢降解,8h之后降解率为98.79%,在pH为1.2的盐酸溶液和pH为7的蒸馏水中几乎不降解。复合微球的降解液溶血率为2.32%,小于5%,说明复合微球不会引起溶血。用微球的降解液培养细胞,细胞的增殖未受到影响,说明复合微球的细胞相容性好。 以盐酸四环素为模型药物制备了载药复合微球,随着投药量的增加,载药率增大,包封率先增大,后又略微减小。盐酸四环素载药复合微球在pH为7.4的PBS缓冲液中进行体外释药实验,结果表明不同淀粉质量分数的载药微球在350min内均可以缓慢释放出药物,超声改性淀粉的质量分数越大,药物释放速度越大。
[Abstract]:In this experiment, ultrasonic modified starch was prepared in a probe type ultrasonic reactor with power of 500W and frequency of 20kHz, and distilled water was used as the medium. The experimental conditions were optimized. With the prolongation of ultrasonic treatment time, the dissolution rate of starch increased, the temperature of solution gradually increased, the optimum ultrasonic treatment time was 10 m min, and the mass fraction of raw starch milk was 20% when the modified starch was prepared. The particle density of modified starch was 838.64 kg / m ~ (3), which was lower than that of original starch. The transmittance of modified starch paste is 55.85, which is higher than that of original starch paste. Using scanning electron microscope (SEM), it was found that ultrasonic treatment did not change the shape of starch particles, but formed many holes and pits on the smooth surface of starch particles. Ultrasonic wave changed the amorphous zone of starch granules, but did not change the crystalline region of starch granules. The ultrasonic modified starch / polyvinyl alcohol / sodium alginate composite microspheres were prepared and the experimental conditions were optimized. When the mass fraction of modified starch is 4, the mass fraction of polyvinyl alcohol is 8, the mass fraction of sodium alginate is 4, the mass fraction of calcium chloride is 5, the morphology of composite microspheres is the best. The best drying method is to dry at room temperature for 24 hours and then to dry at 40 鈩，
本文编号：2371446
[Abstract]:In this experiment, ultrasonic modified starch was prepared in a probe type ultrasonic reactor with power of 500W and frequency of 20kHz, and distilled water was used as the medium. The experimental conditions were optimized. With the prolongation of ultrasonic treatment time, the dissolution rate of starch increased, the temperature of solution gradually increased, the optimum ultrasonic treatment time was 10 m min, and the mass fraction of raw starch milk was 20% when the modified starch was prepared. The particle density of modified starch was 838.64 kg / m ~ (3), which was lower than that of original starch. The transmittance of modified starch paste is 55.85, which is higher than that of original starch paste. Using scanning electron microscope (SEM), it was found that ultrasonic treatment did not change the shape of starch particles, but formed many holes and pits on the smooth surface of starch particles. Ultrasonic wave changed the amorphous zone of starch granules, but did not change the crystalline region of starch granules. The ultrasonic modified starch / polyvinyl alcohol / sodium alginate composite microspheres were prepared and the experimental conditions were optimized. When the mass fraction of modified starch is 4, the mass fraction of polyvinyl alcohol is 8, the mass fraction of sodium alginate is 4, the mass fraction of calcium chloride is 5, the morphology of composite microspheres is the best. The best drying method is to dry at room temperature for 24 hours and then to dry at 40 鈩，
本文编号：2371446
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