مطالعه تجربي اثر فرآوري قليايي بر خواص مكانيكي الياف نخل خرما و چسبندگي آن با رزين اپوكسي

Effect of Alkali Treatment on the Mechanical Properties of Date Palm Fibers and their Adhesion to Epoxy Resin

اﻟﯿﺎف ﻣﻮﺟﻮد در ﻗﺴﻤﺖ ﻫﺎي ﻣﺨﺘﻠﻒ ﻧﺨﻞ ﺧﺮﻣﺎ، ﮐﻪ از ﮔﯿﺎﻫﺎن ﺑﻮﻣﯽ زﯾ ﺴﺖ اﻗﻠﯿﻢ ﺟﻨﻮب اﯾﺮان اﺳﺖ ، از اﻧﻮاع اﻟﯿﺎف ﻃﺒﯿﻌ ﯽ ﺑﻪ ﺷﻤﺎر ﻣﯽروﻧﺪ ﮐﻪ ﻣﯽ ﺗﻮان از آﻧﻬﺎ ﺑﻪ ﻋﻨﻮان ﺗﻘﻮﯾﺖ ﮐﻨﻨﺪه ﮐﺎﻣﭙﻮزﯾﺖﻫﺎي ﭘﻠﯿﻤﺮي ﺑﻬﺮه ﺟﺴﺖ. در اﯾﻦ ﭘﮋوﻫﺶ اﺛﺮ ﻓﺮآوري ﻗﻠﯿﺎﯾﯽ ﺑﺮ روي ﺧﻮاص ﻣﮑﺎﻧﯿﮑﯽ اﻟﯿﺎف ﻧﺨﻞ ﺧﺮﻣﺎ و ﭼﺴﺒﻨﺪﮔﯽ آن ﺑﺎ ﭘﻠﯿﻤﺮ ﮔﺮﻣﺎﺳﺨﺖ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﺗﺠﺮﺑﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. از ﻣﺤﻠﻮل ﺳﺪﯾﻢ ﻫﯿﺪروﮐﺴﯿﺪ )NaOH( در ﺳﻪ ﻏﻠﻈﺖ 1٪، 3٪ ، و 5٪ ﺑﺮاي ﻓﺮآوري ﻗﻠﯿﺎﯾﯽ اﻟﯿﺎف اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. ﺧﻮاص ﻣﮑﺎﻧﯿﮑﯽ اﻟﯿﺎف ﺑﻮﺳﯿﻠﻪ ﺗﺴﺖ ﮐﺸﺶ ﺗﮏ ﻟﯿﻒ و اﺳﺘﺤﮑﺎم ﺑﺮﺷﯽ در ﻓﺼﻞ ﻣﺸﺘﺮك اﻟﯿﺎف و ﻣﺎﺗﺮﯾﺲ ﺑﻮﺳﯿﻠﻪ ﺗﺴﺖ Pull-outاﻧﺪازه ﮔﯿﺮي ﺷﺪ. ﺑﺮرﺳﯽ ﺗﺼﺎوﯾﺮ ﻣﯿﮑﺮوﺳﮑﻮپ اﻟﮑﺘﺮوﻧﯽ روﺑﺸﯽ )SEM( ﺳﻄﺢ اﻟﯿﺎف ﻧﺨﻞ ﺧﺮﻣﺎ ﻗﺒﻞ و ﺑﻌﺪ از ﻓﺮآوري ﻧﺸﺎن دﻫﻨﺪه ﺑﻬﺒﻮد ﮐﯿﻔﯿﺖ ﺳﻄﺢ اﻟﯿﺎف و ﺣﺬف ﻻﯾﻪ ﻫﺎي ﻟﯿﮕﻨﯿﻦ و واﮐﺲ ﭘﺲ از ﻓﺮآوري ﺑﺎ ﻏﻠﻈﺖ 3٪ ﺑﻮد. ﻫﻤﭽﻨﯿﻦ، ﻓﺮآوري ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﻣﻌﻨﺎداري در اﺳﺘﺤﮑﺎم ﮐﺸﺸﯽ، ﻣﺪول اﻻﺳﺘﯿﺴﯿﺘﻪ و ﮐﺮﻧﺶ ﺷﮑﺴﺖ اﻟﯿﺎف ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﺗﺴﺖ Pull-outو ﺑﺮرﺳﯽ ﺗﺼﺎوﯾﺮ SEMﺳﻄﺢ اﻟﯿﺎف ﭘﺲ از ﺗﺴﺖ ﻧﯿﺰ ﻧﺸﺎن دﻫﻨﺪه اﻓﺰاﯾﺶ ﭼﺴﺒﻨﺪﮔﯽ ﻣﺎﺗﺮﯾﺲ ﺑﻪ اﻟﯿﺎف ﺑﻌﺪ از ﻓﺮآوري ﺑﻮد. ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان اﻓﺰاﯾﺶ در ﺧﻮاص ﻣﮑﺎﻧﯿﮑﯽ و ﭼﺴﺒﻨﺪﮔﯽ اﻟﯿﺎف و ﻣﺎﺗﺮﯾﺲ در ﻏﻠﻈﺖ 3٪ ﻣﺸﺎﻫﺪه ﺷﺪ.

The fibers of date palms, which are widely available in the south of Iran, are a variety of natural fibers that can be used as a reinforcement in polymer composites. This work investigates the effect of alkali treatment on the mechanical properties of date palm fibers and their adhesion to thermoset polymer. The sodium hydroxide (NaOH) solution at three different concentrations (1 wt%, 3 wt%, and 5 wt%) was used to treat the fibers. The single fiber tensile test and fiber pull-out tests were performed to measure the mechanical properties and fiber/matrix interfacial share strength, respectively. Comparing the SEM images of the untreated and treated fibers showed that the 3% NaOH treatment could effectively remove non-cellulosic materials, i.e. lignin and wax, with minimum damage to the fiber surface. The experimental results showed a clear improvement of the mechanical properties and fiber/matrix adhesion after treatment. It was found that the 3% NaOH solution is the optimal concentration to achieve the maximum improvement in the fiber and bonding properties.