The inherent properties of starch which are poor mechanical properties and its hydrophilicity that leads to poor long-term water absorption, fostered the incorporation of additives into starch-based bioplastic to enhance its mechanical and barrier properties. Zinc oxide (ZnO) nanoparticle as a lightweight material that is biocompatible, nontoxic, cost-effective and exhibit strong antibacterial activity can be considered as nano reinforcement of starch-based bioplastic. The present work studied the reinforcing effect of ZnO on the physical, mechanical and antibacterial properties of starch-based bioplastic. Bioplastic was prepared by melt-mixing starch and glycerol (3:1, w/w) with ZnO (1%, 2%, 3%, 4% and 5%, w/w). Bioplastic density and water contact angle increased with the increase of ZnO concentration. Bioplastic with the addition of 4% ZnO showed the lowest moisture content of 3.45%. Moreover, the decomposition temperature of bioplastic with ZnO increased slightly which indicated the higher stability. Mechanical properties evaluation showed that bioplastic with addition of ZnO had higher tensile strength than that without ZnO where 4% ZnO exhibited the highest tensile strength of 10.29 MPa with elongation of 5.69%. Cross-section microstructure after tensile test showed that ZnO was fairly dispersed in starch matrix that implied the increase of the mechanical properties of bioplastic. FTIR spectra exhibited that the intermolecular interaction in bioplastics occurred through C–H, C=O, C–O–H and O–H groups. In addition, biodegradability tests of bioplastic showed that the growth of microbes decreased in the presence of ZnO due to the nature of ZnO as an antibacterial compound. The results showed that ZnO played a key role in reinforcing the physical, mechanical and antibacterial properties of starch-based bioplastic.

淀粉的固有性质是较差的机械性能，而其亲水性则导致较差的长期吸水率，促进了将添加剂掺入基于淀粉的生物塑料中以增强其机械性能和阻隔性能。氧化锌（ZnO）纳米颗粒是一种轻质材料，具有生物相容性，无毒，成本效益高和表现出强大的抗菌活性，可以被认为是淀粉基生物塑料的纳米增强材料。本工作研究了ZnO对淀粉基生物塑料的物理，机械和抗菌性能的增强作用。通过将淀粉和甘油（3：1，w / w）与ZnO（1％，2％，3％，4％和5％，w / w）熔融混合来制备生物塑料。随着ZnO浓度的增加，生物塑料的密度和水的接触角增加。添加4％ZnO的生物塑料的最低水分含量为3.45％。此外，ZnO对生物塑料的分解温度略有升高，表明其具有较高的稳定性。力学性能评估表明，添加ZnO的生物塑料的拉伸强度比不添加ZnO的生物塑料更高，其中4％ZnO的最大拉伸强度为10.29 MPa，伸长率为5.69％。拉伸试验后的横截面显微组织表明，ZnO均匀地分散在淀粉基体中，暗示了生物塑料力学性能的提高。FTIR光谱表明，生物塑料中的分子间相互作用是通过C–H，C = O，C–O–H和O–H组发生的。此外，生物塑料的生物降解性测试表明，由于ZnO作为抗菌化合物的性质，在ZnO存在下微生物的生长减少。结果表明，ZnO在增强淀粉基生物塑料的物理，机械和抗菌性能方面起着关键作用。