Low Density Polyethylene/Propolis Blended Films: Mechanical and Biodegradability Properties

In the present study the mechanical and biodegradability properties of Low-Density Polyethylene (LDPE)/propolis blended films were investigated. For this purpose, crude propolis was powdered and was added to the polymer matrix at different percentages of propolis to LDPE (0, 5, 10, 15, and 20 by weight percentages). The films were prepared by the extrusion method. The characterizations of the obtained films were determined by using mechanical (tensile) and biodegradability in soil tests. The study of the microscopic structures of the films was performed using Field Emission Scanning Electron Microscopy (FESEM). FESEM images showed that the surface of the films containing propolis was swollen in the island form as compared to the control and this property expands with the increase in the amount of propolis in the polymer matrix. The mechanical properties of films showed that the addition of propolis to LDPE film reduced the tensile strength and also reduced the relative elongation of the films from 16.5262 and 1%, respectively, for film control to 9.7794 and 0.840% for LDPE film containing 20% propolis. The biodegradability results of these films showed that after 150 days of film placement in the soil, the biodegradability process in the films containing propolis was more rapid than the control. The percentage of soil biodegradability in the film containing 20 percentages of propolis was the highest and reached 5.2 percent. Also, the mechanical properties of the films after 150 days of soil biodegradability also decreased for each film containing propolis than before.