فيلم هاي بر پايه آميزه هاي پلي اتيلن كم چگال/ بره موم : ويژگي هاي مكانيكي و زيست تخريب پذيري

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

در مطالعه حاضر، ويژگي هاي زيست تخريب پذيري و مكانيكي فيلم هاي پلي اتيلني كم چگال (LDPE)آﻣﯿﺨﺘﻪ ﺑﺎ ﺑﺮهﻣﻮم ﺑﺮرﺳﯽ ﺷﺪ. ﺑﺮاي اﯾﻦ ﻣﻨﻈﻮر، ﺑﺮهﻣﻮم ﺧﺎم ﭘﻮدر ﺷﺪ و در ﻧﺴﺒﺖﻫﺎي ﻣﺘﻔﺎوت ﺑﺮهﻣﻮم ﺑﻪ LDPE )5 ،0، 15 ،10، و 20 درﺻﺪ وزﻧﯽ( ﺑﻪ ﻣﺎﺗﺮﯾﺲ ﭘﻠﯿﻤﺮ اﻓﺰوده ﺷﺪ و ﻓﯿﻠﻢﻫﺎ ﺑﻪ روش اﮐﺴﺘﺮوژن ﺗﻬﯿﻪ ﺷﺪﻧﺪ. وﯾﮋﮔﯽﻫﺎي ﻓﯿﻠﻢﻫﺎي ﺑﻪدﺳﺖ آﻣﺪه ﺑﺎ اﺳﺘﻔﺎده از آزﻣﻮنﻫﺎي ﻣﮑﺎﻧﯿﮑﯽ )ﮐﺸﺸﯽ(، و زﯾﺴﺖﺗﺨﺮﯾﺐﭘﺬﯾﺮي در ﺧﺎك ﺗﻌﯿﯿﻦ ﺷﺪﻧﺪ ﻣﻄﺎﻟﻌﻪ ﺳﺎﺧﺘﺎر ﻣﯿﮑﺮوﺳﮑﻮﭘﯽ ﻓﯿﻠﻢﻫﺎ ﺑﻪ ﮐﻤﮏ ﻣﯿﮑﺮوﺳﮑﻮپ اﻟﮑﺘﺮوﻧﯽ روﺑﺸﯽ ﻣﯿﺪان ﻧﺸﺮي )ESEM اﻧﺠﺎم ﺷﺪ. ﺗﺼﻮﯾﺮﻫﺎي FESEM ﺑﺒﺎﻧﮕﺮ آن ﺑﻮد ﮐﻪ ﺳﻄﺢ ﻓﯿﻠﻢﻫﺎي داراي ﺑﺮهﻣﻮم ﻧﺴﺒﺖ ﺑﻪ ﺷﺎﻫﺪ ﺑﻪ ﺻﻮرت ﻧﺎﺣﯿﻪﻫﺎي ﺟﺰﯾﺮهاي ﻣﺎﻧﻨﺪ ﻣﺘﻮرم ﺷﺪه و ﺑﺮهﻣﻮم ﺷﯿﺎرﻫﺎﯾﯽ را در ﺳﻄﺢ ﻓﯿﻠﻢ اﯾﺠﺎد ﮐﺮده اﺳﺖ و اﯾﻦ وﯾﮋﮔﯽ، ﺑﺎ اﻓﺰاﯾﺶ ﻣﻘﺪار ﺑﺮهﻣﻮم در ﻣﺎﺗﺮﯾﺲ ﭘﻠﯿﻤﺮ ﮔﺴﺘﺮش ﻣﯽﯾﺎﺑﺪ. وﯾﮋﮔﯽﻫﺎي ﻣﮑﺎﻧﯿﮑﯽ ﻓﯿﻠﻢﻫﺎ ﻧﺸﺎن داد ﮐﻪ اﻓﺰودن ﺑﺮهﻣﻮم ﺑﻪ ﻓﯿﻠﻢ LDPE ﺑﺎﻋﺚ ﮐﺎﻫﺶ ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ و ﻧﯿﺰ ازدﯾﺎد ﻧﺴﺒﯽ ﻃﻮل ﺗﺎ ﭘﺎرﮔﯽ ﻓﯿﻠﻢ ﻫﺎ ﺑﻪ ﺗﺮﺗﯿﺐ از 16/5262 و 1/00 درﺻﺪ ﺑﺮاي ﻓﯿﻠﻢ ﺷﺎﻫﺪ ﺑﻪ 9/7794و 0/84 درﺻﺪ ﺑﺮاي ﻓﯿﻠﻢ LDPE داراي 20 درﺻﺪ ﺑﺮهﻣﻮم ﮐﺎﻫﺶ ﯾﺎﻓﺖ. ﻫﻤﭽﻨﯿﻦ روﻧﺪ زﯾﺴﺖﺗﺨﺮﯾﺐﭘﺬﯾﺮي در ﺧﺎك در ﻣﺪت زﻣﺎن 150 روز ﺑﺎ اﻓﺰاﯾﺶ ﻏﻠﻈﺖ ﺑﺮهﻣﻮم در آﻣﯿﺰه ﭘﻠﯿﻤﺮي ﺑﺎ ﺳﺮﻋﺖ ﺑﯿﺶﺗﺮي ﻧﺴﺒﺖ ﺑﻪ ﻓﯿﻠﻢ ﺷﺎﻫﺪ ﻫﻤﺮاه ﺑﻮد و ﺑﯿﺸﯿﻨﻪ زﯾﺴﺖﺗﺨﺮﯾﺐﭘﺬﯾﺮي درﺧﺎك ﺑﻪ ﻣﻘﺪار 5/2 درﺻﺪ ﺑﺮاي ﻓﯿﻠﻢ داراي 20 درﺻﺪ ﺑﺮهﻣﻮم رﺳﯿﺪ. وﯾﮋﮔﯽﻫﺎي ﻣﮑﺎﻧﯿﮑﯽ ﻓﯿﻠﻢﻫﺎ ﭘﺲ از ﻃﯽ 150 روز قرار گيري در خاك، براي هر يك از فيلم هاي داراي بره موم نسبت به پيش از قرارگيري آن ها در خاك كاهش يافته بود.

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.