Теплові та механічні властивості композитів епоксидної смоли з неокисненим графеном за малого вмісту графену

• Date: 2020
• Main Authors: Sigareva, N. V., Gorelov, B. M., Mistchanchuk, O. V., Starokadomsky, D. L.
• Format: Article
• Language: English
• Published: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2020
• Subjects: епоксидний композит; неокиснений графен; хімічна стійкість; механічні властивості
• Online Access: https://www.cpts.com.ua/index.php/cpts/article/view/549
• Journal Title: Chemistry, Physics and Technology of Surface

Thermophysical and mechanical properties of epoxy resin compositions with nonoxidized graphene particles have been investigated. The particles were obtained using the electrochemical method and they had a block structure with a thickness of about 50 nm. The particle concentrations in the composites were C = 1.0, 2.0 and 5.0 % for thermophysical studies and 0.1, 0.2, 0.5 and 1.0 % for mechanical measurements.Thermophysical measurements of the composite destruction were performed by method of thermo-programmable desorption with mass spectrometric recording of volatile products in the temperature range 40-800 оС. The main effect of the introduction of unoxidized graphene particles is a sharp increase in the thermal stability of the composite and a decrease in the amount of the released volatile products Qi in the low graphene loading at C ? 1 %. With increasing loading, the value of Qi nonmonotonously reduces with a maximum at C = 2.0 %.Concentration dependences of the amount of the released volatile products and the activation energy of thermodestruction for volatile products were determined. The thermodesorption activation energy Ed for atomic fragments, which was determined from the Wigner-Polanyi equation, reduced. The Ed slightly and nonmonotonously increases with a maximum at C = 2 %. It has been shown that the run of the Ed (С) dependence correlates with the Qi (С) behavior.Models describing growth of thermal stability and variations of mechanical parameters are proposed. Compressive strength and elastic modulus have been measured in the low concentration range at C ? 1 %. It has been found that the parameters nonmonotonously vary with maximum at C = 0.01 %. The absence of correlation between the behavior of mechanical parameters and the thermal stability of graphene composites is related with various reasons. Behavior of mechanical parameters is caused by variation in elastic and conformational deformations of polymer chains upon loading gaphene filler in the polymer. The growth in thermal stability may be attributed to partial removal of heat flux energy at the interface in the electronic subsystem of graphene particles with subsequent lowering vibrational energy of atoms  at the interface.