ارائه ي روشي نوين با تركيب ساخت رشته ي ذوبي (FFF)/فوم توده اي به منظور بهبود خواص قطعات پليمري زيست تخريب پذير پلي لاكتيك اسيد

Introducing A Novel Combined Method of Fused Filament Fabrication (FFF)/Batch Foaming to Improve the Properties of Biodegradable Poly Lactic Acid

اﻫﻤﯿﺖ ﻣﺴﺎﺋﻞ زﯾ ﺴﺖ ﻣﺤﯿﻄ ﯽ ﮔﺴﺘﺮدﮔﯽ روز اﻓﺰون ﮐﺎرﺑﺮد ﭘ ﻠﯿﻤﺮﻫﺎ ي ز ﯾﺴﺖ ﺗﺨﺮ ﯾ ﺐﭘﺬﯾﺮ را در ﭘﯽ داﺷﺘﻪ اﺳﺖ ﺑﻪﻃﻮري ﮐﻪ اﻣﺮوزه اﯾﻦ ﭘﻠﯿﻤﺮﻫﺎ ﺑﻪ ﺟﺰء ﺟﺪاﯾﯽ ﻧﺎﭘﺬﯾﺮ در ﻋﻠﻮم ﭘﺰﺷﮑ ﯽ و ز ﯾﺴﺘﯽ ﺑﺪل ﮔﺸﺘﻪاﻧﺪ. در ﺗﺤﻘﯿﻖ ﺣﺎﺿﺮ از ﯾﮏ روش ﻧﻮﯾﻦ ﮐﻪ ﺗﺮﮐ ﯿﺒﯽ از روش ﺳﺎﺧﺖ رﺷﺘﻪ ذوﺑﯽ ) FFF( و ﻓﻮم ﺗﻮدها ي اﺳﺖ ﺟﻬﺖ ﺑﻬﺒﻮد ﺧﻮاص ﻗﻄﻌﺎت از ﺟﻨﺲ ﭘ ﻠﯽﻻﮐﺘ ﯿ ﮏ اﺳﯿﺪ اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. ﺑﺮ اي اﯾﻦ ﻣﻨﻈﻮر ﻧﻤﻮﻧﻪﻫﺎي ﭼﺎﭘﯽ ﺑﺎ درﺻﺪ ﭼﮕﺎﻟ ﯽ ﭘﺮ ﺷﺪن 100، 80و 60ﺗﻮﻟ ﯿﺪ ﺷﺪه و ﺳﭙﺲ ﻓﻮم ﺷﺪﻧﺪ. ﺑﻪ دﻟﯿ ﻞ اﻫﻤﯿ ﺖ و ﺗﺎﺛﯿ ﺮ ﮐﺴﺮ ﺗﻮﺧﺎﻟﯽ )Void fraction( ﺑﺮ ﺧﻮاص ﺳﺎﺧﺘﺎر ي و ﻣﮑﺎﻧ ﯿﮑ ﯽ و ﻫﻤﭽﻨ ﯿﻦ ﺳﺮﻋﺖ ﺗﺠﺰﯾﻪﭘﺬﯾﺮ ي ﻣﻮاد ﺑﺎ ﺳﺎﺧﺘﺎر ﻣﺘﺨﻠﺨﻞ ﺑﺨﺼﻮص ﺑﺎ ﻣﻘﺎﺻﺪ ﭘﺰﺷﮑ ﯽ ، دو ﭘﺎراﻣﺘﺮ ﮐﺴﺮ ﺗﻮﺧﺎﻟﯽ و اﺳﺘﺤﮑﺎم ﺑﻪ ﺿﺮﺑﻪ ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ درﺻﺪ ﮐﺴﺮ ﺗﻮﺧﺎﻟ ﯽ ﻧﻤﻮﻧﻪﻫﺎي ﻓﻮم ﻧﺸﺪه ﺑﺮ اي درﺻﺪ ﭘﺮ ﺷﺪن 100، 80و 60ﺑﻪ ﺗﺮﺗ ﯿ ﺐ3 ، 13و 25درﺻﺪ ﻣ ﯽﺑﺎﺷﺪ، در ﺻﻮرﺗﯽﮐﻪ اﯾﻦ ﻣ ﯿﺰان ﺑﻌﺪ از ﻓﻮم ﺷﺪن ﻧﻤﻮﻧﻪﻫﺎ ﺑﻪ ﺗﺮﺗ ﯿﺐ ﺑﻪ 14، 19و 30درﺻﺪ رﺳ ﯿﺪ. ﻫﻤﭽﻨﯿ ﻦ ﻧﺘﺎﯾﺞ ﺣﮑﺎﯾﺖ از اﻓﺰ اﯾﺶ اﺳﺘﺤﮑﺎم ﺑﻪ ﺿﺮﺑﻪ ﻧﻤﻮﻧﻪﻫﺎي ﭼﺎﭘﯽ ﺑﺎ اﺳﺘﻔﺎده از ﻓﺮآﯾﻨﺪ ﻓﻮم داﺷﺖ. ﺑﻪ ﻃﻮر ي ﮐﻪ ﺑﺮاي ﻧﻤﻮﻧﻪﻫﺎ ي ﺑﺎ درﺻﺪ ﭘﺮﺷﺪن 100، ﻣﻘﺪار اﺳﺘﺤﮑﺎم ﺑﻪ ﺿﺮﺑﻪ ﺑﺎ ﻓﺮآﯾﻨﺪ ﻓﻮم ﺷﺪن از 207ﺑﻪ 506ژول ﺑﺮ ﻣﺘﺮ ﻣﺮﺑﻊ رﺳ ﯿﺪ ﮐﻪ ﺑﻪ دﻟﯿﻞ ﺳﻠﻮلﻫﺎي اﯾﺠﺎد ﺷﺪه ﺑﻪ روش ﻓﻮم ﺗﻮدها ي در اﺑﻌﺎد ﻧﺎﻧﻮﻣﺘﺮ ي ﺑﻮد.

The importance of environmental issues has increased the use of biodegradable polymers which nowadays have become among main components in medical and biological applications. In the present study, a new combined method of fused filament fabrication (FFF) and batch foaming was introduced to improve the properties of poly lactic acid. For this purpose, FFF samples were produced with infill percentages of 100, 80 and 60 and then, foamed in batch process. Due to the importance and effect of the void fraction on structural and mechanical performance as well as the biodegradability of materials with porous structure, especially for medical purposes, void fraction and impact strength were evaluated. The results showed that the void fractions of FFF samples were 3%, 13% and 25% in infill percentages of 100, 80 and 60, respectively while after the foaming they reached to 14%, 19% and 30%. The findings revealed that the impact strength of FFF foamed samples was improved compared to FFF solid samples. For samples with 100 infill percentage, the impact strength improved from 207 to 506 J/m2 due to the foaming procedure with nano-sized cells created by the batch foaming.