Microstructural and thermal properties of fluoroelastomer/acidic surface modified carbon nanotube nanocomposites
Acid surface modified carbon nanotube (MCNT) carbon nanotube (CNT) filled fluoroelastomer (FE) and unfilled FE were prepared (MCNT/FE, CNT/FE, and FE) Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) showed that the glass transition temperature (Tg) of MCNT/FE is less than that of CNT/FE and FE. The storage modulus of CNT/FE is higher than that of MCNT/FE over the whole temperature range. Storage modulus in rubbery state is higher in the case of MCNT/FE when compared to FE, however, in glassy state, it is slightly higher. For MCNT/FE at glassy and rubbery state, loss modulus is less than that of CNT/FE. Loss modulus in rubbery states is higher in the case of MCNT/FE compared to FE and in glassy states for both are the same. The DSC, DMA, and X ray diffraction (XRD) results confirmed that the FE and filler/FE is partially crystalline mostly in g form. MCNT and CNT together with shear and high temperature, induced g crystallinity in the FE, g phase melting of MCNT/FE is higher than that of CNT/FE and FE. Most probably MCNT/FE obeys behaviors of thin films with high surface energy substrate interactions, while in CNT/FE the substrate surface energy is lower. XRD and DSC showed that MCNT causes more g crystallinity in FE compared to others. Tetrafluoroethylene segments crystals have the degree of crystallinity in the order of CNT/FE MCNT/FE FE. The g phase crystal size is in the order of FE CNT/FE MCNT/FE. XRD, DSC, and DMA results for FE and filler/FE confirmed each other. POLYM. COMPOS. 2015. (c) 2015 Society of Plastics Engineers