增塑剂对淀粉基复合薄膜性能的影响

Effect of plasticizers on the properties of starch-based composite film

淀粉是最具发展潜力的天然生物降解材料之一,但由其制备的薄膜力学性能较差,脆性也较大。为了提升淀粉基薄膜的韧性,以甘油、木糖醇、聚乙烯醇(PVA1788)、聚乙二醇(PEG400)和山梨醇作为增塑剂,对淀粉基复合薄膜进行增塑改性,探究不同增塑剂对淀粉基复合薄膜性能的影响。结果表明:增塑剂对淀粉基复合薄膜的拉伸性能影响显著,当甘油和PVA1788的添加量分别为水基的2.63%和0.95%时,共同增塑得到的淀粉基复合薄膜满足拉伸强度高于5MPa、断裂伸长率大于20%的性能要求;甘油分别与木糖醇和PEG400复配制得的复合薄膜的断裂伸长率也有明显提高;从溶解度来看,甘油与PEG400复配增塑时,淀粉基复合薄膜的溶解度最大,溶解性能最好;与甘油复配增塑膜相比,单一甘油增塑膜的表面更加平整,甘油与淀粉基复合薄膜的相容性最好。通过加入增塑剂,可以得到与明胶胶囊薄膜力学性能相当的淀粉基复合薄膜,未来有望替代明胶制备淀粉基植物胶囊。

Starch is one of the most potential natural biodegradable materials,but the film prepared by it has poor mechanical properties and is also brittle.In order to improve the toughness of starch based films,glycerol,xylitol,polyvinyl alcohol(PVA1788),polyethylene glycol(PEG400)and sorbitol are used as plasticizers to plasticize starch based composite films,and the effects of different plasticizers on the properties of starch based composite films are explored.The results show that the addition of plasticizer has a significant effect on the tensile properties of starch-based composite films.The starch-based composite films obtained by co-plasticizing can meet the performance requirements of tensile strength higher than 5 MPa and breaking tensile rate higher than 20%,when the addition of glycerol and PVA1788 are 2.63%and 0.95%of starch,respectively.In addition,the breaking elongation of the starch based composite films prepared with glycerol and xylitol and PEG400 respectively has a significant increase.From the solubility point of view,when compounding glycerol with PEG400,the starch based composite film has the largest solubility and the best solubility;compared with the compounding film,the surface of the single glycerol based composite film is smoother,and the compatibility between glycerol and starch based composite film is the best.By adding plasticizer,starch based composite film with the same mechanical properties as gelatin capsule film can be obtained,which is expected to replace gelatin to prepare starch based plant capsule in the future.