Abstract：A series of citric acid modified starch/polyvinyl alcohol composite membranes were preparedby solution casting method to prepare a new environment ally friendly plastic wrap． Structure and proper-ties of composite membrane was characterized by means of infrared spectroscopy，universal testing ma-chine，moisture permeable machine，light transmittance/haze measuring instrument and other analyticalmethods，and discussed the effect of citric acid dosage on the performance of the composite membranewere discussed． The results showed that the citric acid and starch were esterified and cross-linked． Thecitric acid modified starch could improve the mechanical properties of the composite membrane，reducethe haze，hydrophilicity and water vapor transmission rate of the film，and improve the preservation of thefilm to mango． When the citric acid content was 3. 3%，the mechanical properties were optimized，andthe tensile strength and elongation at break were increased by 42% and 79%，respectively．
2019, Vol. 32 
