添加海藻酸钠的乙酸酯淀粉薄膜的制备

Preparation and properties of starch acetate films adding sodium alginate

以马铃薯淀粉为原料,采用超声波预处理,以乙酸酐为酯化剂,制备乙酸酯淀粉;再以乙酸酯淀粉为成膜主料,添加定量海藻酸钠(SA),制备了乙酸酯淀粉薄膜。采用正交试验法研究了成膜工艺条件,并测定了淀粉薄膜的性能。结果表明:乙酸酯淀粉制备工艺为马铃薯淀粉乳质量浓度0.10g/mL,于30℃超声处理15min,加入乙酸酐进行酯化反应,得到乙酸酯淀粉,酯化度为0.0433;当乙酸酯淀粉质量浓度为0.05g/mL,甘油质量浓度0.02g/mL,质量分数为4%的聚乙烯醇5mL,SA质量浓度0.01g/mL,制备的乙酸酯淀粉薄膜的拉伸强度为20.45MPa,断裂伸长率为11.23%。

Starch acetate was prepared with potato starch as raw material that was pretreated by ultrasonic and acetic anhydride as esterification agent. Then starch acetate blend films were made with starch acetate as the main materials and sodium alginate（SA） as additives. The film-forming process was tested by orthogonal experiment and the properties of the film were determined as well. The results show that the preparation conditions are as follows：the potato starch emulsion whose mass concentration is 0.10 g/mL is pretreated at 30℃ via ultrasonic vibration for 15 min,then it is reacted with acetic anhydride to produce starch acetate whose degree of esterification reaches 0.0433. The tensile strength and alongation at break of the films are 20.45 MPa and 11.23% when the mass fraction of 4% of polyvinyl alcohol is 5 mL,the mass concentration of glycerol,starch acetate and SA are 0.02,0.05,0.01 g/mL respectively.