湿法共混制备聚丁二酸丁二醇酯/淀粉食品包装膜

Preparation of Food Packaging Film of Poly (butylene succinate)/Starch by Wet Blending

以水和甘油为增塑剂,将玉米淀粉与聚丁二酸丁二醇酯(PBS)直接湿法共混得到母粒,进而流延制备了PBS/淀粉薄膜.扫描电镜(SEM)观察发现,用甘油/水混合增塑的淀粉可以在PBS基体中均匀的分散,与淀粉干法填充改性相比,原位塑化后的淀粉与PBS的相容性得到明显改善,并且薄膜的综合力学性能较好.甘油∶水为1∶2,增塑剂用量为淀粉的15%时,薄膜的横纵向拉伸强度在淀粉含量为11.5%时最高,此时横纵向断裂伸长率分别较纯PBS薄膜提高了147.2%和51.3%,横纵向直角撕裂强度分别提高了160.8%和57.3%.随淀粉填充量的不断增加,薄膜的横纵向拉伸强度和直角撕裂强度都有所下降,但横纵向断裂伸长率却在淀粉填充量为30%时最高.在淀粉填充量高达25%和30%时,薄膜横纵向拉伸强度仍分别可以满足GB/T 4456—1996"包装用聚乙烯吹塑薄膜"中规定的A类优等品和合格品的要求.该薄膜材料在满足食品等包装使用需求的同时,有效地降低了成本,并且可以完全生物降解.

Poly （ butylene and H2O, then blending succinate） （PBS）/starch film was prepared by in situ plasticization of glycerol PBS with corn starch wetly, and finally extrusion casting. SEM observation showed the starch using the mix of water and glycerin as plasticizer could be dispersed evenly in the matrix of PBS, the compatibility between starch and PBS was improved evidently due to the in situ plasticizing of starch, and the comprehensive mechanical properties of the film were enhanced comparing with dry starch packing modification. The highest tensile strengths both in length and breadth of the film could be observed when starch content was 11.5% and the ratio of glycerol to H2O was 1： 2. Comparing with the neat PBS film, elongation at break in length and breadth increased by 147.2% and 51.3% , and the right angle tear strength in length and breadth increased by 160.8% and 57.3% , respectively. Both the tensile strength and angle tear strength decreased with the increase of starch content. The highest break elongations both in length and breadth could be obtained with a starch content of 30%. The biodegradable films were suitable for practical application and could meet the requirement of GB/T 4456-1996 even with the high starch content of 25% and 30%.