丙烯酰胺改性壳聚糖/氧化海藻酸钠复合薄膜的制备及性能研究

Preparation and Property Research of Acrylamide-Modified Chitosan/Oxidized Sodium Alginate Composite Film

本研究以丙烯酰胺(AM)在碱-尿素体系下循环冻融法对壳聚糖(CS)进行改性,基于席夫碱反应制备得到丙烯酰胺改性壳聚糖/氧化海藻酸钠(AMCS/OSA)复合薄膜。采用红外光谱对AMCS/OSA复合薄膜的内部结构进行表征,研究了OSA含量、浸泡时间和甘油含量对AMCS/OSA复合薄膜的力学性能、水蒸气透过率和自愈合效率的影响。结果表明,当AM与CS的摩尔比为7:1时,可以制备水溶性为3%(质量分数)的AMCS;当甘油添加量为4%(质量分数)、OSA含量为2%(质量分数)、浸泡时间为15min时,制备得到的AMCS/OSA复合薄膜的拉伸强度、断裂伸长率和水蒸气透过率分别为5.31MPa、50.7%和0.507g/(m^(2)·24h),在温度25℃、相对湿度55%的条件下,静置8h后,自愈合效率为76.7%。研究结果表明,该AMCS/OSA复合薄膜具有优异的力学性能和可自愈合性,可以应用于食品包装领域。

In this study,AM was used to modify CS by cyclic freeze-thaw method in the alkali-urea system.Based on the Schiff base reaction,AMCS/OSA composite film was prepared.The structure of AMCS/OSA film was characterized using ATR-FTIR spectroscopy.The effects of the concentration OSA solution,the immersion time the addition of glycerin on the mechanical properties,water vapor transmittance and self-healing efficiency were investigated.The results indicated that when the molar ratio of AM to CS was 7:1,AMCS with water-solubility of 3 wt%can be prepared;when the content of glycerol,OSA and soaking time were set as 4 wt%,2 wt%and 15 min,the tensile strength of the prepared AMCS/OSA composite film reached 5.31 MPa,the elongation at break was 50.7%,and the water vapor transmission rate was 0.507 g/(m^(2)·24 h),respectively.Meanwhile,the self-healing efficiency of AMCS/OSA composite film was 76.7%under the conditions of a temperature of 25℃and a relative humidity of 55%for 8 hours.This AMCS/OSA composite film with excellent mechanical and self-healing properties has broad prospects in the field of food packing.