چكيده به لاتين
Abstract:
Nowadays carbon nanoparticles, especially CNTs due to their unique properties have gained significant importance. Incorporating CNTs into polymer matrices such as Epoxy, which is one of the most widely used polymers, improves characteristics and increases the efficiency of its properties. Nevertheless, the CNT particles tend to agglomerate, which causes it difficult to achieve a homogenous dispersion in Epoxy. In this project, CNT was functionalized in two ways; which include acid treatment and Amino acid treatment. The effect of temperature (60, 90, 110 °C), acid treatment time (15, 30, 60 min), pre ultrasonication and wt% of nanoparticles (0.5, 1, 3, 5) were investigated on performance of Epoxy nanocomposites containing treated CNTs. In addition, effects of Amino acid concentration in the aqueous solution during functionalization reaction (4, 50, 100 g/lit) and wt% of nanoparticles (0.5, 1, 2) on the performance of Epoxy nanocomposites containing amino acids treated CNTs were studied. Also the performance of Epoxy nanocomposites containing treated CNTs, untreated CNT and neat Epoxy were compared. Treated CNTs were analyzed by FTIR, UV-Visible, titration analyses and solvent stability test. Epoxy nanocomposites containing CNT and treated CNTs were studied by mechanical tensile and flexural tests and analyzed by DMTA, DSC and TGA analyses. The results showed that in both ways functional groups successfully attached to the surface of CNT. In the case of solvent stability, acid treated CNT was stable just for an hour in different solvents, but those treated with Amino acid last three days in ethanol and one month in DMF. Tensile strength, tensile modulus and tensile toughness for acid treated samples in comparison to neat Epoxy were, respectively 59, 69 and -32 percent and for amino acid treated samples were respectively 67, 52 and -19 higher (lower). Flexural strength, flexural modulus and flexural toughness of acid treating method samples to neat Epoxy were, respectively 27, 59 and 49 percent and for amino acid treating method were, respectively 18, 51 and 33 percent higher. In the Acid treating approach, storage modulus did not increase in comparison to neat Epoxy, but the glass transition temperature increased by 1.1 °C. While in Amino acid treating approach storage modulus and glass transition temperature increase respectively, 15% and 6.9 °C. Acid treating method decreases Epoxy cure reaction temperature by 9.1 °C and Amino acid treating declined it by 13.3 °C. An increase to thermal stability of acid and Amino acid treated samples was not observed.
Keywords: Epoxy, Carbon Nanotube, Functionalization, Acid treatment, Amino acid
